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Claw trimming routines in relation to claw lesions, claw shape and lameness in Norwegian dairy herds housed in tie stalls and free stalls
Preventive Veterinary Medicine 73 (2006) 255–271 www.elsevier.com/locate/prevetmed
Claw trimming routines in relation to claw lesions, claw shape and lameness in Norwegian dairy herds housed in tie stalls and free stalls ˚ .M. Sogstad a,b, O. Østera˚s a,b T. Fjeldaas a,*, A a
Norwegian School of Veterinary Science, P.O. Box 8146, Dep. 0033 Oslo, Norway b TINE Norwegian Dairies BA, P.O. Box 58, 1431 A˚s, Norway
Received 22 December 2004; received in revised form 17 August 2005; accepted 16 September 2005
Abstract We assessed the prevalence of claw lesions, abnormal claw shapes and lameness in relation to most-recent claw-trimming routines in Norwegian dairy herds housed in tie stalls and free stalls. Equal-sized groups were randomly sampled from both tie and free stalls in each of the three most animal-dense regions in Norway. The study population consisted of 2551 cows of the Norwegian Red breed housed in 54 tie stalls and 52 free stalls. Fourteen educated claw trimmers performed claw trimming and recording of claw lesions once during the spring of 2002. A multivariable model including cluster effects and individual-cow factors was fit for each claw lesion and abnormal claw shape. In tie-stall herds with routine trimming 39.9% of the cows had one or more lesions or abnormal shapes in front or hind claws versus 52.8% in herds with no routine trimming. Hind-claw results in tie stalls with concrete stall base: herds trimmed occasionally had more haemorrhages of the white line (OR = 2.8) and corkscrewed hind claws (OR = 3.6) versus herds trimmed routinely; herds never trimmed had more heel-horn erosions (OR = 2.6) versus herds trimmed routinely and less haemorrhages of the white line (OR = 0.3) and the sole (OR = 0.2) versus herds trimmed occasionally. In free-stall herds with routine trimming 76.8% of the cows had one or more lesions or abnormal shapes in front or hind claws versus 68.9% in herds with no routine trimming. Hind-claw results in free stalls with concrete stall base: herds never trimmed had less haemorrhages of the white line (OR = 0.3) and the sole (OR = 0.3) versus herds trimmed routinely; and also less haemorrhages of the * Corresponding author. Tel.: +47 22964935; fax: +47 22964762. E-mail address: [email protected] (T. Fjeldaas). 0167-5877/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.prevetmed.2005.09.004
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white line (OR = 0.3) and white-line fissures (OR = 0.3) versus herds trimmed occasionally. Hindclaw results in free stalls with rubber-mat stall base: herds trimmed occasionally had less heel-horn erosions (OR = 0.5) and more dermatitis (OR = 5.4) versus herds trimmed routinely. The routine claw trimming performed in Norwegian free stalls has not had the desired effects on claw lesions and abnormal claw shapes. Routine trimming in tie stalls, however, seems to have prevented claw disorders. # 2005 Elsevier B.V. All rights reserved. Keywords: Claw trimming; Claw lesions; Claw shape; Lameness; Tie stalls; Free stalls
1. Introduction Functional claw trimming re-establishes appropriate weight bearing and function within and between the claws of each foot. Corrective claw trimming removes loose or damaged horn and relieves weight-bearing in diseased claws, which is supposed to promote recovery and reduce discomfort (Toussaint Raven, 1989; Shearer and van Amstel, 2001). Routine claw trimming has been recommended to prevent claw disease and to detect and treat lesions at an early stage (Kloosterman, 1997; Bergsten et al., 1998). Ward (1999) however, stated that it is essential that claw trimming is performed with the correct technique. Shearer and van Amstel (2004) concluded that overtrimming easily can occur regardless of the claw-trimming method. Claws exposed to much wear must be left with a thicker sole to reduce the risk of tenderness after trimming (Bergsten et al., 1998). In free-stall housing there is more movement than in tie stalls, and the claws are exposed to a more complex environment. The intention with claw trimming and the consequences might be different in herds housed in free stalls compared to herds housed in tie stalls. Claw trimming improves shape and prevents lesions for 4–8 months (Shearer and van Amstel, 2001; Manske et al., 2002; van Amstel et al., 2002b). Long intervals between trimmings increase the risk of infectious claw diseases (Somers, 2004). Feeding rations high in rapidly fermentable carbohydrates is associated with lameness (Manson and Leaver, 1989) and sole ulcers (Peterse et al., 1984), and milk yield is a risk factor for heel-horn erosion and sole ulcer (Enevoldsen et al., 1991a,b). Consequently, the need for routine claw trimming might also differ according to feeding regimens and milk yield in the herd. In Norway occasional trimming usually means that approximately 5–20% of the cows in the herd are trimmed when the farmer assumes it is needed. In most herds with routine trimming the claws of all cows and some of the heifers are trimmed once a year. The trimming is performed by professionals or by the herdsmen themselves. Most professional trimmers and herdsmen were previously not trained formally for the task of clawtrimming. Our aim was to assess the prevalence of claw lesions, abnormal claw shapes and lameness in relation to most-recent trimming routines in Norwegian dairy herds housed in tie stalls and free stalls with concrete or rubber flooring.
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2. Materials and methods 2.1. Selection procedure The project ‘‘Claw health of Norwegian cattle’’ which includes the present study was designed as a cross-sectional study. Our aim was to end up with 120 study herds: twenty tiestall herds and 20 free-stall herds in each of the three most animal-dense regions of Norway. Herds with at least 15 milking cows were included. The herds were sorted according to their official ID-numbers in the Norwegian Animal Recording Database. Approximately 500 herds from each area were sampled by computerized systematic assignment with a randomly drawn starting number. The herds were described by local advisors as being housed in tie stalls or free stalls. Approximately equal-sized groups were sampled from both free stalls and tie stalls within each region. One hundred and ninetythree farmers were invited to participate and 136 responded positively. Reasons for dropouts before claw trimming were busy farmers and claw trimmers, shortage of assistance, illness of the farmer and no suitable place to perform claw trimming (n = 13). One herd was excluded because claw trimming was performed after the herd was let out on summer pasture. Lack of compliance of one claw trimmer led to 10 herds being excluded from the study. Thirty-nine animals were excluded for practical reasons: other disease, close to parturition, soon going to slaughter or aggressive behaviour. One tie-stall herd and two free-stall herds with wooden stall base and three free-stall herds with deep litter were excluded in this study. 2.2. Study population The final study population consisted of 106 herds and 2551 cows and included all cows and heifers less than 30 days from first calving at claw trimming. Fifty-four herds (1100 cows) were housed in tie stalls and 52 herds (1451 cows) in free stalls. The mean number of cows per herd and per parity, the mean lactation stage at trimming and the milk production per cow (stratified by housing type) are in Table 1. The numbers of herds and cows by stall features are in Table 2. There were slatted concrete alleys in 48 free stalls and solid concrete in 4. Electric trainers were regularly used in 37 tie stalls, occasionally used in 9 and never used in 8. The concentrate/grass silage ratio was almost identical in tie stalls and free stalls, but cows in tie stalls spent more time at pasture. Zero grazing was practiced in 11 free-stall herds and 1 tie-stall herd. All herds had been housed for more than 3 months at claw trimming. Professional trimmers had performed the most-recent routine trimming in 30 herds and the herdsman in 13. Most professional trimmers had used electric grinders with hard-metal abrasive discs; most herdsmen had used sanded abrasive discs. Recording of most-recent trimming methods was not possible, but we assume that the traditional Norwegian approach was performed: the sole of the longest claw is trimmed first, and the major aim is to balance the heels of the two claws. Some trimmers dish out the horn of the axial sole. In three tie stalls and four free stalls the last routine trimming was performed <6 months before the recordings. In the rest of the herds with routine trimming the cows had been trimmed >6 months before. Footbaths had not been used in any of the herds.
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Table 1 Number of herds (n), mean number of cows in the herds, number of cows in each parity (n), mean days in milk at claw trimming (DIMT) and mean milk production per cow with S.D. at different trimming routines in 106 Norwegian dairy herds in 2002 Type of stall
Routine trimming n
Tie stalls Herds Cows
Mean
22 –
– 21
173 124 127
– – –
– –
Free stalls Herds Cows Parity 1 2 >2
Parity 1 2 >2 DIMT Milk production
DIMT Milk production
S.D.
Occasional trimming
No trimming at all
n
n
– 5.7
Mean
22 –
– 21
– – –
184 128 155
153 6327
107 1089
21 –
– 32
249 175 227 – –
S.D.
Mean
S.D.
– 8.0
10 –
– 21
– 7.6
– – –
– – –
86 55 69
– – –
– – –
– –
162 6237
123 742
– –
136 5962
99 855
– 13
21 –
– 25
– 11
10 –
– 31
– 11
– – –
– – –
193 132 172
– – –
– – –
127 78 98
– – –
– – –
160 6482
113 843
– –
156 6411
117 847
– –
143 6195
111 615
Table 2 Number of dairy herds (n) and cows (n) with different trimming routines in tie stalls and free stalls with concrete or rubber-mat stall base, Norway, 2002 Trimming
Tie stalls
Free stalls
Concrete
Routine Occasional Not at all
Rubber mats
Concrete
Rubber mats
Herds
Cows
Herds
Cows
Herds
Cows
Herds
Cows
16 22 10
303 467 209
6 0 0
121 0 0
17 12 6
541 239 190
4 9 4
110 258 113
2.3. Recruitment and training of personel Fourteen professional claw trimmers attended two courses held by two of the authors. The program was based on acknowledged pedagogical principles and the experience from a pilot study (Fjeldaas et al., 2002). The theoretical and practical teaching included clawtrimming procedures and diagnosis, recording and treatment of claw diseases. All the important aspects of measuring claw length and trimming and recording of diseases were repeated to get a general agreement among the claw trimmers before the initiation of the project. One author also gave individual training to each claw trimmer in one or two herds
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at the project start. A summary of the observations and any ambiguities was sent to all claw trimmers. 2.4. Recording of data The cows were trimmed once within the period from the 1st of January 2002 to summer let out onto pasture. The last trimming was performed the 28th of June. Twelve trimmers used electric grinders with hard-metal abrasive discs, one used a hard-metal bladed disc and one used blade and mallet. Lameness was assessed when the animal was moved to the trimming chute. The criteria for recording of lameness and claw lesions being present (Table 3) were adapted from Bergsten (2000). If there was no lameness or claw lesion, no notation was made. Other abscesses, interdigital phlegmones, horizontal or vertical fissures, interdigital hyperplasias, double soles, under-run heels and papillomatous dermatitis were recorded as ‘‘other findings’’. The dorsal-wall length was measured with a slide gauge on the right lateral front and hind claws from the coronary band along the dorsal border to the apex of the claw. Abnormal claw shapes (including asymmetric and corkscrewed claws) were also recorded. Corkscrewed claws included both mild cases where the abaxial wall was bent inwards with a curved dorsal border and serious cases of corkscrew claws where the abaxial wall was part of the weight-bearing surface. The lengths of corkscrewed claws were not measured. 2.5. Data handling and statistical analyses Data recorded at the farm were transferred to SAS version 8.0 for statistical analyses. Most lesions and abnormal shapes were recorded in hind claws and analyses were performed only on these. Table 3 Definition of lameness and claw lesions recorded at trimming Lesion
Abbreviation
Definition for minimum sign of lesion being present
Lameness
L
Dermatitis
D
Heel-horn erosion
E
Haemorrhages of the white line Haemorrhages of the sole Sole ulcer White-line fissure
HWL
Asymmetric gait, bearing weight on all limbs Superficial, hyperaemic, slightly exudative lesion of the digital/ interdigital skin Slight defects of the horn integrity, pits and small fissures Slight haemorrhagic discoloration
HS
Slight haemorrhagic discoloration
SU WLF
Exposed, unaffected corium Fissure which disappears with deep cut beneath normal trimming level
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Fig. 1. Hind-claw lesions in tie stalls with concrete stall base and free stalls with concrete or rubber-mat stall base and different claw-trimming routines, 95% confidence interval. D: dermatitis, E: heel-horn erosions, HWL: haemorrhages of the white line, HS: haemorrhages of the sole, SU: sole ulcers, WLF: white-line fissures.
The prevalences were calculated for claw lesions and abnormal claw shapes stratified by stall type, trimming routines and the type of trimmer. Calculations of 95% CI for prevalence were based on normal approximation for the binomial proportion except when np or n(1 p) <10. Then absolute values were calculated. A separate cow-level multivariable model was fit for each claw lesion and abnormal claw shape with each lesion and shape as dependent variables using PROC GENMOD with binomial distribution, logit link function and Wald statistics type-3 contrasts. Because some groups contained few animals, the models were stratified on housing and stall base as an
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Table 4a Significant result estimates of the final multivariable models describing routine vs. occasional trimming as to hindclaw lesions and corkscrewed hind claws within housing and stall base, Norwegian diary cows, 2002 Effects
b
S.E.
P
Haemorrhages of the white line (HWL) in tie stalls with concrete stall base. Dfs: 765, deviance: 464.4, delta deviance for trimming routine: 13.0 Intercept 1.98 0.32 <0.001 Months in milk at claw trimming 0.05 0.10 ns Months in milk at claw trimming2 0.0064 0.0092 ns Trimming (routine vs. occasional) 1.03 0.40 <0.01 Random effect of herd (a1) 0.88 0.20 <0.001 Corkscrewed claws (Cork) in tie stalls with concrete stall base. Dfs: 690, deviance: 211.25, delta deviance for trimming routine: 7.13 Intercept 2.76 0.38 <0.001 a Parity 1 0.95 0.55 a Parity 2 0.61 0.39 Parity >2 – – – Trimming (routine vs. occasional) 1.29 0.55 <0.05 Random effect of herd (a1) 0.76 0.36 <0.05 Dermatitis (D) in free stalls with rubber-mat stall base. Dfs: 364, deviance: 160.76, delta deviance for trimming routine: 5.26 Intercept 2.59 0.53 <0.001 Months in milk at claw trimming 0.12 0.08 ns 0.0093 0.0047 <0.05 Months in milk at claw trimming2 Trimming (routine vs. occasional) 1.69 0.68 <0.05 Random effect of herd (a1) 1.07 0.71 ns Heel-horn erosions (E) in free stalls with rubber-mat stall base. Dfs: 364, deviance: 499.46, delta deviance for trimming routine: 7.3 Intercept 0.95 0.68 ns Months in milk at claw trimming 0.083 0.081 ns 0.0045 0.0093 ns Months in milk at claw trimming2 Trimming (routine vs. occasional) 0.77 0.27 <0.01 Random effect of herd (a1) 1.53 0.35 <0.001 Random effect of claw trimmer (a2) 1.55 0.57 <0.01 a
Within same letter P < 0.01.
alternative to including interaction terms. Trimming routine, lactation stage at trimming and parity were included as fixed effects. Trimming was classified as routine, occasional or no trimming at all. Lactation stage was made continuous and used both as linear and square independent variable. Parity was classified as 1, 2 and >2. Only the independent variables and the random effect of herd and claw trimmer were included when found significant for the same claw lesions by Sogstad et al. (2005a,b). These random effects were expressed as a1 and a2 by using the LOGOR statement. Each model was evaluated by deviance and delta deviance with and without the fixed effect of claw trimming (Dohoo et al., 2003). No elimination procedure was performed despite lack of significance for the fixed or random effect variables. A separate mixed model was run for hind-claw length. The model included trimming routine as fixed effect and herd and claw trimmer as random effects.
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The agreement between asymmetric-or corkscrewed hind claws and lameness/hind claw lesions at claw-level was calculated on binary scores using Kappa-analyses (Altman, 1991). k was calculated with 95% confidence interval.
3. Results 3.1. Claw lesions In tie-stall herds with routine trimming 39.9% (95% CI; 35.2, 44.5) of the cows had one or more lesions or abnormal shapes in front or hind claws versus 52.8% (49.0; 56.6) in herds with no routine. In free-stall herds with routine trimming 76.8% (73.6; 80.1) of the cows had one or more lesions or abnormal shapes in front or hind claws versus 68.9% (65.7; 72.1) in herds with no routine. Hind-claw prevalences are in Fig. 1. Significant results based on multivariable-model analyses are in Tables 4a–4c and Table 5. No difference between herdsmen and professional trimmers as to the prevalence of claw lesions was revealed in the multivariable models. Table 4b Significant result estimates of the final multivariable models describing routine vs. no trimming as to hind-claw lesions within housing and stall base, Norwegian diary cows, 2002 Effects
b
S.E.
P
Heel-horn erosions (E) in tie stalls with concrete stall base. Dfs: 508, deviance: 240.9, delta deviance for trimming routine: 1.5 Intercept 1.77 0.51 <0.001 Months in milk at claw trimming 0.16 0.11 ns 0.02 0.01 0.06 Months in milk at claw trimming2 Trimming (routine vs. no) 0.97 0.45 <0.05 Random effect of herd (a1) 2.99 0.68 <0.001 Random effect of claw trimmer (a2) 2.53 1.00 <0.05 Haemorrhages of the white line (HWL) in free stalls with concrete stall base. Dfs: 726, deviance: 565.9, delta deviance for trimming routine: 19.3 Intercept 2.87 0.56 <0.001 Months in milk at claw trimming 0.24 0.11 <0.05 0.031 0.012 <0.01 Months in milk at claw trimming2 Trimming (routine vs. no) 1.22 0.55 <0.05 Random effect of herd (a1) 0.56 0.24 <0.05 Haemorrhages of the sole (HS) in free stalls with concrete stall base. Dfs: 726, deviance: 666.4, delta deviance for trimming routine: 31.9 Intercept 3.31 0.48 <0.001 Months in milk at claw trimming 0.69 0.14 <0.001 0.073 0.013 <0.001 Months in milk at claw trimming2 Parity 1 0.37 0.27 ns Parity 2 0.13 0.20 ns Parity >2 – – – Trimming (routine vs. no) 1.26 0.48 <0.01 Random effect of herd (a1) 0.34 0.15 <0.05
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Table 4c Significant result estimates of the final multivariable models describing occasional vs. no trimming as to hind-claw lesions within housing and stall base, Norwegian diary cows, 2002 Effects
b
S.E.
P
Haemorrhages of the white line (HWL) in tie stalls with concrete stall base. Dfs: 671, deviance: 413.0, delta deviance for trimming routine: 14.2 Intercept 3.25 0.65 <0.001 Months in milk at claw trimming 0.021 0.11 ns Months in milk at claw trimming2 0.0046 0.0094 ns Trimming (occasional vs. no) 1.36 0.60 <0.05 Random effect of herd (a1) 0.93 0.21 <0.001 Sole ulcers (SU) in tie stalls with concrete stall base. Dfs: 671, deviance: 174.1, delta deviance for trimming routine: 6.6 Intercept 5.31 0.75 <0.001 Months in milk at claw trimming 0.50 0.28 0.07 0.057 0.035 0.10 Months in milk at claw trimming2 Trimming (occasional vs. no) 1.69 0.67 <0.05 Random effect of herd (a1) 0.64 0.41 0.11 Haemorrhages of the white line (HWL) in free stalls with concrete stall base. Dfs: 419, deviance: 273.5, delta deviance for trimming routine: 14.0 Intercept 2.96 0.76 <0.001 Months in milk at claw trimming 0.42 0.27 ns 0.057 0.026 <0.05 Months in milk at claw trimming2 Trimming (occasional vs. no) 1.15 0.60 <0.05 Random effect of herd (a1) 0.47 0.19 <0.05 White-line fissures (WLF) in free stalls with concrete stall base. Dfs: 427, deviance: 265.4, delta deviance for trimming routine: 14.0 Intercept 2.97 0.52 <0.001 Trimming (occasional vs. no) 1.13 0.59 <0.05 0.57 0.24 <0.05 Random effect of herd (a1)
3.2. Claw shapes Hind-claw lengths are in Fig. 2 and results based on mixed-model analyses are in Table 6. Prevalences of cows with asymmetric and corkscrewed hind claws are in Fig. 3. Multivariable-model analyses revealed no significant difference between trimming routines for asymmetric hind claws. However, more cows had corkscrewed hind claws in tie stalls with concrete stall base and occasional versus routine trimming (Table 4a and Table 5). No difference between herdsmen and professionals as to the prevalence of abnormal claw shapes was revealed in the multivariable models. We found only poor prevalence agreements between claw shapes and the various lesions; the largest was that for corkscrewed hind claws and haemorrhages of the sole (k = 0.14; 95% CI: 0.10, 0.18).
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Table 5 Significant odds ratios (OR) of the multivariable models for different claw-trimming routines as to hind-claw lesions and corkscrewed hind claws within housing and stall base, 95% confidence interval (CI), Norwegian diary cows, 2002 Type of housing and stall base
Claw lesion
Occasional vs. routine trimming
No vs. routine trimming
No vs. occasional trimming
OR
CI
OR
CI
OR
CI
Tie stalls with concrete stall base
E HWL SU Cork
– 2.8 – 3.6
– 1.3; 6.1 – 1.2; 10.7
2.6 – – –
1.1; 6.4 – – –
– 0.3 0.2
– 0.1; 0.8 0.05; 0.7
Free stalls with concrete stall base
HWL HS WLF
– – –
– – –
0.3 0.3 –
0.1; 0.9 0.1; 0.7 –
0.3 – 0.3
0.1; 1.0 – 0.1; 1.0
Free stalls with rubber-mat stall base
D E
5.4 0.5
1.4; 21.0 0.3; 0.8
D: dermatitis; E: heel-horn erosions; HWL: haemorrhages of the white line; HS: haemorrhages of the sole; SU: sole ulcers; WLF: white-line fissures; Cork: corkscrewed claws.
Fig. 2. Hind-claw length in tie stalls and free stalls with concrete or rubber-mat stall base and different trimming routines, 95% confidence interval.
3.3. Lameness In tie stalls the prevalence of lameness was 0.7% both in herds with routine trimming and herds with no routine. In free stalls the prevalence of lame cows was 2.0% with routine trimming and 1.1% with no routine. The difference was not significant.
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Table 6 Results of final mixed models describing hind-claw length as to claw-trimming routines within housing and stall base, Norwegian diary cows, 2002 S.E.
P
Percentage
Tie stalls with concrete stall base (972 cowsb) Intercept 78.6 Routine trimming 3.2 Occasional trimming 1.8 No trimming at all – Random effect of herd – Random effect of claw trimmer –
Effects
b
2.1 2.0 1.9 – – –
<0.001 ns ns – – –
– – – – 14 23
Tie stalls with rubber-mat stall base (121 cowsb) Intercept 97.3 Random effect of herd – Random effect of claw trimmer –
4.2 – –
<0.001 – –
– 29 22
3.4 3.68 3.97 –
<0.001 ns ns –
– – – – 37 11
2.6 3.67 3.11 – – –
<0.001
– – – – 23 0
Free stalls with concrete stall base (956 cowsb) Intercept 83.6 Routine trimming 0.33 Occasional trimming 1.83 No trimming at all – Random effect of herd Random effect of claw trimmer Free stalls with rubber-mat stall base (472 cowsb) Intercept 82.8 Routine trimming 5.77 Occasional trimming 3.21 No trimming at all – Random effect of herd – Random effect of claw trimmer – a b
a a
– – –
Within same letter P < 0.01. The claw length of corkscrewed claws were not measured and altogether 30 cows are missing.
Fig. 3. Abnormal hind-claw shapes in tie stalls with concrete stall base and free stalls with concrete or rubber-mat stall base and different trimming routines, 95% confidence interval.
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4. Discussion 4.1. Representativeness Although the most-recent claw-trimming routines in the study population were not known at the sampling stage, we assumed the distribution of trimming routines to be representative for Norwegian dairy herds. We imposed the herd-size eligibility criterion to assure that we got several cows per herd, and because the herd size is increasing in Norway. All losses and drop-outs occurred before the statistical analyses. Differences in recording between claw trimmers might have biased our results. One person doing all the recordings was considered, but none had the time to visit all herds. Fewer claw trimmers would have lead to one trimmer having a very large influence on the outcome. The lack of significant cluster effect within claw trimmer except for heel-horn erosions, asymmetric claws and claw length indicates that the inter-observer variability was satisfactory. A test to evaluate sensibility and specificity of trimmer-recordings based on diagnosis of claw lesions on slides was considered but not performed, because simulation of the field situation was impossible. Although we expected that the mostimportant lesions were recorded, we realised as reported by Manske (2003), that particularly mild lesions might have been underreported in our study. The interval since last routine trimming was 6–12 months in most herds. This might have influenced the evaluation of different claw-trimming routines. If the assessment had been performed in the autumn, however, there would have been a large effect of pasture. Our aim was to evaluate different trimming routines in tie stalls and free stalls, and consequently the cows had to be housed for a certain time in advance. In epidemiological studies there will always be the uncertainty around causal mechanisms. What makes the herdsmen decide to trim their cows? Long claws were probably a major reason for trimming. Cows in tie stalls with rubber-mat stall base had the longest claws and all were trimmed routinely. Because normal claw shape is no guarantee for healthy claws the sample of cows chosen for occasional trimming probably did not include all cows that needed to be trimmed. Another reason for trimming might have been many lame cows. However, a 2% prevalence of lame cows was probably not the main reason for initiating routine trimming, although we assume that not all lame cows were detected in our study and that the real prevalence of lameness was higher. Many cows with heel-horn erosions might also have been a reason for trimming. Unless heel-horn erosions are serious with secondary pododermatitis, there will usually be no lameness. Bad odour and the obvious fissures at the bulb of the heel might, however, initiate claw trimming. 4.2. Statistical analyses The data material was too small to run complete models with all interactions for some of the groups, and models were fit for each combination of trimming with housing and stall base. Separate models were more robust. Only models for groups with a sufficient number of observations were included. Due to little power in the separate models we included the fixed effects that were significant for the specified dependent variables in the paper of
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Sogstad et al. (2005a), even when not significant in the particular model. We expected the same associations in these analyses because the material was almost equal. Due to many separate models being evaluated, the interpretation of P-values >0.01 should be done with care to avoid type-1 error. The material was, however, rather small and too low limits for significance would have increased the type-2 error rate. 4.3. Claw lesions 4.3.1. Heel-horn erosions and dermatitis Fewer cows with heel-horn erosions in tie stalls with concrete stall base and routine trimming versus no trimming might have been a positive effect of claw trimming. The reason for more heel-horn erosions and less dermatitis in free stalls with routine versus occasional trimming is not obvious. The difference being significant in free stalls with rubber mats and not in stalls with concrete might have been a consequence of longer claws with routine versus occasional trimming in stalls with rubber mats, but not on concrete. Improper trimming resulting in low heels and increased pressure on the heel and the bulb might have predisposed the routinely trimmed claws to heel-horn erosions. However, more heel-horn erosions might have been an incitement to routine trimming. There is no plausible explanation for the corresponding low prevalence of dermatitis. Somers (2004) found that claw-trimming intervals >7 months were related to more digital dermatitis, interdigital dermatitis and heel-horn erosions in free stalls; Manske et al. (2002) found that dermatitis and heel-horn erosions were most prevalent in the spring even if the animal had been trimmed the autumn before. This might imply that there is only a brief preventive effect of claw trimming on dermatitis and heel-horn erosions, and that trimming intervals >6 months are too long in free stalls. Enevoldsen et al. (1991b) found that high daily milk yields were associated with high risk of heelhorn erosions. Low prevalence of heel-horn erosions and the lowest daily milk yields being found in herds with no trimming at all in our study indicates that feeding intensity influenced the need for claw trimming. A secondary effect of low-intensity feeding is drier manure and consequently a cleaner environment, which we expect to prevent infectious claw lesions. Poor hygiene (Philipot et al., 1994) and dirty cows (Sogstad et al., 2005a) are risk factors for heel-horn erosions. 4.3.2. Haemorrhages of the white line and the sole Occasional claw trimming being related to haemorrhages of the white line in tie stalls with concrete stall base might indicate no preventive effect and a need for routine trimming. Probably, only cows with long claws, abnormal claw shapes or lameness were trimmed previously and not cows with subclinical claw lesions and low-grade lameness. More haemorrhages in free stalls with concrete stall base and routine trimming versus those with no trimming might be a consequence of uncomfortable cubicles. The lying time on concrete stall base might have been reduced and if trimming was incorrectly performed, the risk for claw lesions would increase. Excessive shortening of the toe, leaving it square ended and removal of the axial wall are the most common faults of trimming (Blowey, 2002) and a thicker sole is required when the cows spend a long time walking on hard surfaces. By physical experiments van der Tool (2004) showed that the sole and bulb of
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recently trimmed claws were subject to the highest pressure. He advised that more weight should be distributed to the wall, which is the strongest part of the claw. It is our experience that many Norwegian trimmers make the dorsal wall too short and the sole too thin. It is also quite common to remove too much of the axial wall. This might explain why no trimming at all was related to fewer haemorrhages of the sole than occasional or routine trimming in free stalls with concrete stall base. Most free stalls had slatted concrete alleys which cause shorter strides, larger step abduction and more asymmetrical walking than on solid floors (Telezhenko et al., 2002). This combined with improper trimming might have increased the risk for bruising of the sole. 4.3.3. Sole ulcers and white-line fissures More sole ulcers in tie stalls and more white-line fissures in free stalls with concrete stall base and occasional versus no trimming at all might be explained by a higher risk for ulcers and also no preventive effect of trimming in occasionally trimmed herds. That routine trimming was not significantly better than occasional trimming might have been a consequence of too long time since last trimming. At spring trimming Manske et al. (2002) found that the prevalence of lesions associated with laminitis and the need for acute treatments between scheduled trimmings were reduced by additional autumn trimming. However, by annual claw trimming Burgi (1998) reduced sole ulcers and white-line diseases to less than 2%. Because there was no difference between professional trimmers and herdsmen in our study it might be questioned if the mostrecent trimmings were performed with the necessary skills. It is our experience that many Norwegian herdsmen have inadequate trimming technique. This is probably a consequence of small herds and little practice. Enevoldsen et al. (1991a) found that low milk yield alone and high milk yield combined with high body weight were important risk factors for sole ulcers in lactation 1, whereas low milk yield combined with high body weight was important in later lactations. Lowest prevalence of sole ulcers and lowest milk yields in tie stalls with no trimming at all in our study emphasizes that milk yield influences the need for claw trimming. The reason might be that nutrition influences the horn’s growth rate (van Amstel and Shearer, 2001) and the risk for clawhorn disruption (Hoblet and Weiss, 2001). 4.4. Claw shapes 4.4.1. Length of the dorsal wall Shorter claws with occasional versus routine trimming in free stalls with rubber-mat stall base might explain why routine trimming was not performed. The result indicates that equilibrium between growth and wear had been established for cows not trimmed. The horn of the wall grows at a rate of 5 mm per month, with a range of 0.2–8.5 mm and the horn of the sole grows at the rate of 3 mm per month (van Amstel and Shearer, 2001). Hahn et al. (1986) found that the monthly dorsal-wall growth rate during first lactation was 6.6 mm for hind claws, and Logue et al. (1993) concluded that the claws quickly return to their ‘‘pre-trim’’ look. Manson and Leaver (1988) found that trimming increased claw-horn growth. This might partly explain why longer claws were recorded in some herds with routine trimming.
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4.4.2. Asymmetric and corkscrewed claws More corkscrewed claws recorded in tie stalls with concrete stall base and occasional versus routine trimming indicate that routine trimming was preventive. However, routine trimming did not prevent corkscrewed hind claws in free stalls in our study. That the cow is moving in a much more complex environment in free stalls might have a greater impact on claw shape than trimming once or twice a year. We assume that corrective trimming of corkscrewed claws is not as long-lasting in free stalls as in tie stalls and that trimming intervals <6 months are probably required. Because we expect professionals to perform trimming of higher quality than herdsmen, no difference between herdsmen and professional trimmers for abnormal claw shapes indicates that the professionals’ technique was not optimal. Poor agreement between abnormal claw shapes and most claw lesions confirms that claw lesions often occur independently of abnormal claw shape. However, the agreement between corkscrewed hind claws and haemorrhages of the sole partly agrees with van Amstel et al. (2002a) who stated that haemorrhages of the white line and the sole, whiteline separations and sole ulcers are commonly observed in corkscrew claws. 4.5. Lameness Low prevalence of lameness in our study probably explains why no significant difference between the trimming routines in neither tie nor free stalls was revealed. Manson and Leaver (1988) found that preventive trimming reduced both lameness and the duration of claw diseases. Logue et al. (1993) stated that regular claw trimming will not ‘‘stop’’ lameness but that it ‘‘helps’’. 4.6. Trimming interval and technique Long intervals since last trimming in the study herds indicate long trimming intervals which might have been a reason for small or no benefits of routine trimming in free stalls. However, there were equally long intervals in tie stalls and most lesions and abnormal claw shapes in those herds seemed to benefit from routine claw trimming. Our results might indicate that the routine-trimming intervals in free stalls, to a larger extent than in tie stalls, have to be adjusted for the individual herd. Huber et al. (2004) found that functional claw trimming every 6-months improved claw health both in tie stalls and free stalls. Type of stall base and type of alleys were not reported. However, Huang et al. (1995) found that a 4months trimming interval was worse than longer intervals for heel-horn erosions, interdigital dermatitis, laminitis and white-line separation, but not for sole ulcers and corkscrew claws. The type of housing was not reported in the study. No difference between professionals and herdsmen in our study indicates that the mostrecent trimmings were not performed with the necessary skills. Nu¨ske (1998) found that the incidence of serious claw diseases was decreased after functional claw trimming was introduced. Vermunt (1999) emphasized that functional claw trimming can improve locomotion and restore claw shape, but only if carried out correctly. Another study concluded that biological resilience to mechanical forces might be impaired by inappropriate claw trimming (Webster, 2002).
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5. Conclusion Our study suggests that routine claw trimming prevents claw disorders in Norwegian tie stalls while occasional trimming has minor preventive effect. Low prevalence of claw disorders despite no trimming at all in tie-stall herds with low milk yield indicates a decreased need for claw trimming in these herds. Our study also indicates that routine claw trimming in Norwegian free stalls has not had the desired preventive effects.
Acknowledgements We are grateful to the participating claw trimmers and farmers, as well as Stig Larsen, Norwegian School of Veterinary Studies, for his statistical support and ideas. The study was funded by TINE Norwegian Dairies BA, GENO Breeding and A.I. Association, Norwegian Meat Research Centre and The Research Council of Norway. Access to data was given by the Norwegian Dairy Herd Recording System and the Norwegian Cattle Health Services in agreement number 6/2001 by 19.09.2001.
References Altman, D.G. (Ed.), 1991. Practical Statistics for Medical Research. Chapman & Hall/CRC, London. Bergsten, C., 2000. Workshop report about the documentation of claw diseases. Part 2. In: Mortellaro, C.M., De Vecchis, L., Brizzi, A. (Eds.), Proceedings of the 11th International Symposium on Disorders of the Ruminant Digit, Parma, pp. 12–16. Bergsten, C., Hultgren, J., Manske, T., 1998. Claw traits and foot lesions in Swedish dairy cows in relation to trimming interval and housing system. A preliminary report. In: Lischer, C.J., Ossent, P. (Eds.), Proceedings of the 10th International Symposium on Lameness in Ruminants, Lucerne, pp. 46–48. Blowey, R.W., 2002. Claw trimming-how should it be done? A comparison of two approaches. In: Shearer, J.K. (Ed.), Proceedings of the 12th International Symposium on Lameness in Ruminants, Orlando, pp. 122– 126. Burgi, K., 1998. Determine maintenance hoof trimming by observing movement. In: Lischer, C.J., Ossent, P. (Eds.), Proceedings of the 10th International Symposium on Lameness in Ruminants, Lucerne, pp. 20– 22. Dohoo, I., Martin, W., Stryhn, H., 2003. Veterinary Epidemiologic Research. In: McPike, S.M. (Ed.), AVC Inc. Charlottetown, Transcontinental Prince Edward Island. Enevoldsen, C., Gro¨hn, Y.T., Thysen, I., 1991a. Sole ulcers in dairy cattle: associations with season, cow characteristics, disease, and production. J. Dairy Sci. 74, 1284–1298. Enevoldsen, C., Gro¨hn, Y.T., Thysen, I., 1991b. Heel erosion and other interdigital disorders in dairy cows: associations with season, cow caracteristics, disease, and production. J. Dairy Sci. 74, 1299–1309. Fjeldaas, T., Forshell, K.P., Østera˚s, O., 2002. Monitoring claw diseases in the Norwegian cattle population. In: Shearer, J.K. (Ed.), Proceedings of the 12th International Symposium on Lameness in Ruminants, Orlando, pp. 329–332. Hahn, M.V., McDaniel, B.T., Wilk, J.C., 1986. Rates of hoof growth and wear in Holstein cattle. J. Dairy Sci. 69, 2148–2156. Hoblet, K.H., Weiss, W., 2001. Metabolic hoof horn disease: claw horn disruption. Vet. Clin. N. Am. Food Anim. Pract. 17, 111–127. Huang, Y.C., Shanks, R.D., McCoy, G.C., 1995. Evaluation of fixed factors affecting hoof health. Livest. Prod. Sci. 44, 115–124.
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Huber, J., Stanek, C., Troxler, J., 2004. Effects of regular claw trimming in different housing systems. In: Zemljic, B. (Ed.), Proceedings of the 13th International Symposium on Lameness in Ruminants, Maribor, pp. 116– 117. Kloosterman, P., 1997. Claw care. In: Greenough, P.R., Weaver, A.D. (Eds.), Lameness in Cattle, third ed. W.B. Saunders Company, Philadelphia, pp. 123–142. Logue, D.N., Offer, J.E., Kempson, S.A., 1993. Lameness in dairy cattle. Ir. Vet. J. 46, 47–58. Manske, T., Hultgren, J., Bergsten, C., 2002. The effect of claw trimming on the hoof health of Swedish dairy cattle. Prev. Vet. Med. 54, 113–129. Manske, T., 2003. Om klo¨vva˚rdares klo¨vhaˆlsoregistreringar. (Claw health recordings by claw trimmers) Sven. Vet. Tidn. 15, 11–18. Manson, F.J., Leaver, J.D., 1988. The influence of dietary protein intake and of hoof trimming on lameness in dairy cattle. Anim. Prod. 47, 191–199. Manson, F.J., Leaver, J.D., 1989. The effect of concentrate: silage ratio and hoof trimming on lameness in dairy cattle. Anim. Prod. 49, 15–22. Nu¨ske, S., 1998. Functional trimming of the claw—experiences and influences on veterinary treatment after three years of practice at the experimental farm of Oberschleissheim, University of Munich. (Poster). In: Lischer, C.J., Ossent, P. (Eds.), Proceedings of the 10th International Symposium on Lameness in Ruminants, Lucerne, pp. 28–29. Peterse, D.J., Korver, S., Oldenbroek, J.K., Talmon, F.P., 1984. Relationship between levels of concentrate feeding and incidence of sole ulcers in dairy cattle. Vet. Rec. 115, 629–630. Philipot, J.M., Pluvinage, P., Cimarosti, I., Sulpice, P., Bugnard, F., 1994. Risk factors of dairy cow lameness associated with housing conditions. Vet. Res. 25, 244–248. Shearer, J.K., van Amstel, S.R., 2001. Functional and corrective claw trimming. Vet. Clin. N. Am. Food Anim. Pract. 17, 53–72. Shearer, J.K., van Amstel, S.R., 2004. Claw health management and therapy of infectious claw diseases. In: Kaske, M., Scholz, H., Ho¨lterschinken, M. (Eds.), Recent developments and perspectives in bovine medicine: keynote lectures from the 22nd World Buiatric Congress, Hannover, 2002, pp. 258–267. ˚ .M., Fjeldaas, T., Østera˚s, O., 2005a. Lameness and claw lesions of the Norwegian Red diary cattle Sogstad, A housed in free stalls in relation to environment, parity and stage of lactation. Acta Vet. Scand. 46, 203–217. ˚ .M., Fjeldaas, T., Østera˚s, O., Forshell, P.K., 2005b. Prevalence of claw lesions in Norwegian dairy Sogstad, A cattle housed in tie stalls and free stalls. Prev. Vet. Med. 70, 191–209. Somers, J., 2004. Claw disorders and disturbed locomotion in dairy cows: the effect of floor systems and implications for animal welfare. Ph.D. thesis. University of Utrecht, Utrecht. Telezhenko, E.V., Bergsten, C., Manske, T., 2002. Cow locomotion on slatted and solid floors assessed by trackway analysis (Poster). In: Shearer, J.K. (Ed.), Proceedings of the 12th International Symposium on Lameness in Ruminants, Orlando, pp. 417–419. Toussaint Raven, E., 1989. Cattle Foot Care and Claw Trimming. Farming Press, Ipswich. van Amstel, S.R., Palin, F.L., Shearer, J.K., 2002a. Application of functional trimming procedures to corkscrew claws. In: Shearer, J.K. (Ed.), Proceedings of the 12th International Symposium on Lameness in Ruminants, Orlando, pp. 99–108. van Amstel, S.R., Palin, F.L., Shearer, J.K., 2002b. Claw trimming: an adaption of the Dutch method. In: Shearer, J.K. (Ed.), Proceedings of the 12th International Symposium on Lameness in Ruminants, Orlando, pp. 127– 130. van Amstel, S.R., Shearer, J.K., 2001. Abnormalities of hoof growth and development. Vet. Clin. N. Am. Food Anim. Pract. 17, 73–91. van der Tool, P.P.J., 2004. Biomechanical aspects of the claw—floor interaction in dairy cattle. Implications for Locomotion and Claw Disorders. Ph.D. Thesis. University of Utrecht, Utrecht. Vermunt, J., 1999. Regular claw trimming for the control of lameness—good or bad? Vet J. 157, 109–110. Ward, W.R., 1999. Lameness in dairy cattle—an overview. Cattle Pract. 7, 333–340. Webster, J., 2002. Effect of environment and management on the development of claw and leg diseases. In: Kaske, M., Scholz, H., Ho¨ltershinken, M. (Eds.), Recent developments and perspectives in bovine medicine: keynote lectures from the 22nd World Buiatrics Congress, Hannover, pp. 248–256.
Claw trimming routines in relation to claw lesions, claw shape and lameness in Norwegian dairy herds housed in tie stalls and free stalls ˚ .M. Sogstad a,b, O. Østera˚s a,b T. Fjeldaas a,*, A a
Norwegian School of Veterinary Science, P.O. Box 8146, Dep. 0033 Oslo, Norway b TINE Norwegian Dairies BA, P.O. Box 58, 1431 A˚s, Norway
Received 22 December 2004; received in revised form 17 August 2005; accepted 16 September 2005
Abstract We assessed the prevalence of claw lesions, abnormal claw shapes and lameness in relation to most-recent claw-trimming routines in Norwegian dairy herds housed in tie stalls and free stalls. Equal-sized groups were randomly sampled from both tie and free stalls in each of the three most animal-dense regions in Norway. The study population consisted of 2551 cows of the Norwegian Red breed housed in 54 tie stalls and 52 free stalls. Fourteen educated claw trimmers performed claw trimming and recording of claw lesions once during the spring of 2002. A multivariable model including cluster effects and individual-cow factors was fit for each claw lesion and abnormal claw shape. In tie-stall herds with routine trimming 39.9% of the cows had one or more lesions or abnormal shapes in front or hind claws versus 52.8% in herds with no routine trimming. Hind-claw results in tie stalls with concrete stall base: herds trimmed occasionally had more haemorrhages of the white line (OR = 2.8) and corkscrewed hind claws (OR = 3.6) versus herds trimmed routinely; herds never trimmed had more heel-horn erosions (OR = 2.6) versus herds trimmed routinely and less haemorrhages of the white line (OR = 0.3) and the sole (OR = 0.2) versus herds trimmed occasionally. In free-stall herds with routine trimming 76.8% of the cows had one or more lesions or abnormal shapes in front or hind claws versus 68.9% in herds with no routine trimming. Hind-claw results in free stalls with concrete stall base: herds never trimmed had less haemorrhages of the white line (OR = 0.3) and the sole (OR = 0.3) versus herds trimmed routinely; and also less haemorrhages of the * Corresponding author. Tel.: +47 22964935; fax: +47 22964762. E-mail address: [email protected] (T. Fjeldaas). 0167-5877/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.prevetmed.2005.09.004
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white line (OR = 0.3) and white-line fissures (OR = 0.3) versus herds trimmed occasionally. Hindclaw results in free stalls with rubber-mat stall base: herds trimmed occasionally had less heel-horn erosions (OR = 0.5) and more dermatitis (OR = 5.4) versus herds trimmed routinely. The routine claw trimming performed in Norwegian free stalls has not had the desired effects on claw lesions and abnormal claw shapes. Routine trimming in tie stalls, however, seems to have prevented claw disorders. # 2005 Elsevier B.V. All rights reserved. Keywords: Claw trimming; Claw lesions; Claw shape; Lameness; Tie stalls; Free stalls
1. Introduction Functional claw trimming re-establishes appropriate weight bearing and function within and between the claws of each foot. Corrective claw trimming removes loose or damaged horn and relieves weight-bearing in diseased claws, which is supposed to promote recovery and reduce discomfort (Toussaint Raven, 1989; Shearer and van Amstel, 2001). Routine claw trimming has been recommended to prevent claw disease and to detect and treat lesions at an early stage (Kloosterman, 1997; Bergsten et al., 1998). Ward (1999) however, stated that it is essential that claw trimming is performed with the correct technique. Shearer and van Amstel (2004) concluded that overtrimming easily can occur regardless of the claw-trimming method. Claws exposed to much wear must be left with a thicker sole to reduce the risk of tenderness after trimming (Bergsten et al., 1998). In free-stall housing there is more movement than in tie stalls, and the claws are exposed to a more complex environment. The intention with claw trimming and the consequences might be different in herds housed in free stalls compared to herds housed in tie stalls. Claw trimming improves shape and prevents lesions for 4–8 months (Shearer and van Amstel, 2001; Manske et al., 2002; van Amstel et al., 2002b). Long intervals between trimmings increase the risk of infectious claw diseases (Somers, 2004). Feeding rations high in rapidly fermentable carbohydrates is associated with lameness (Manson and Leaver, 1989) and sole ulcers (Peterse et al., 1984), and milk yield is a risk factor for heel-horn erosion and sole ulcer (Enevoldsen et al., 1991a,b). Consequently, the need for routine claw trimming might also differ according to feeding regimens and milk yield in the herd. In Norway occasional trimming usually means that approximately 5–20% of the cows in the herd are trimmed when the farmer assumes it is needed. In most herds with routine trimming the claws of all cows and some of the heifers are trimmed once a year. The trimming is performed by professionals or by the herdsmen themselves. Most professional trimmers and herdsmen were previously not trained formally for the task of clawtrimming. Our aim was to assess the prevalence of claw lesions, abnormal claw shapes and lameness in relation to most-recent trimming routines in Norwegian dairy herds housed in tie stalls and free stalls with concrete or rubber flooring.
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2. Materials and methods 2.1. Selection procedure The project ‘‘Claw health of Norwegian cattle’’ which includes the present study was designed as a cross-sectional study. Our aim was to end up with 120 study herds: twenty tiestall herds and 20 free-stall herds in each of the three most animal-dense regions of Norway. Herds with at least 15 milking cows were included. The herds were sorted according to their official ID-numbers in the Norwegian Animal Recording Database. Approximately 500 herds from each area were sampled by computerized systematic assignment with a randomly drawn starting number. The herds were described by local advisors as being housed in tie stalls or free stalls. Approximately equal-sized groups were sampled from both free stalls and tie stalls within each region. One hundred and ninetythree farmers were invited to participate and 136 responded positively. Reasons for dropouts before claw trimming were busy farmers and claw trimmers, shortage of assistance, illness of the farmer and no suitable place to perform claw trimming (n = 13). One herd was excluded because claw trimming was performed after the herd was let out on summer pasture. Lack of compliance of one claw trimmer led to 10 herds being excluded from the study. Thirty-nine animals were excluded for practical reasons: other disease, close to parturition, soon going to slaughter or aggressive behaviour. One tie-stall herd and two free-stall herds with wooden stall base and three free-stall herds with deep litter were excluded in this study. 2.2. Study population The final study population consisted of 106 herds and 2551 cows and included all cows and heifers less than 30 days from first calving at claw trimming. Fifty-four herds (1100 cows) were housed in tie stalls and 52 herds (1451 cows) in free stalls. The mean number of cows per herd and per parity, the mean lactation stage at trimming and the milk production per cow (stratified by housing type) are in Table 1. The numbers of herds and cows by stall features are in Table 2. There were slatted concrete alleys in 48 free stalls and solid concrete in 4. Electric trainers were regularly used in 37 tie stalls, occasionally used in 9 and never used in 8. The concentrate/grass silage ratio was almost identical in tie stalls and free stalls, but cows in tie stalls spent more time at pasture. Zero grazing was practiced in 11 free-stall herds and 1 tie-stall herd. All herds had been housed for more than 3 months at claw trimming. Professional trimmers had performed the most-recent routine trimming in 30 herds and the herdsman in 13. Most professional trimmers had used electric grinders with hard-metal abrasive discs; most herdsmen had used sanded abrasive discs. Recording of most-recent trimming methods was not possible, but we assume that the traditional Norwegian approach was performed: the sole of the longest claw is trimmed first, and the major aim is to balance the heels of the two claws. Some trimmers dish out the horn of the axial sole. In three tie stalls and four free stalls the last routine trimming was performed <6 months before the recordings. In the rest of the herds with routine trimming the cows had been trimmed >6 months before. Footbaths had not been used in any of the herds.
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Table 1 Number of herds (n), mean number of cows in the herds, number of cows in each parity (n), mean days in milk at claw trimming (DIMT) and mean milk production per cow with S.D. at different trimming routines in 106 Norwegian dairy herds in 2002 Type of stall
Routine trimming n
Tie stalls Herds Cows
Mean
22 –
– 21
173 124 127
– – –
– –
Free stalls Herds Cows Parity 1 2 >2
Parity 1 2 >2 DIMT Milk production
DIMT Milk production
S.D.
Occasional trimming
No trimming at all
n
n
– 5.7
Mean
22 –
– 21
– – –
184 128 155
153 6327
107 1089
21 –
– 32
249 175 227 – –
S.D.
Mean
S.D.
– 8.0
10 –
– 21
– 7.6
– – –
– – –
86 55 69
– – –
– – –
– –
162 6237
123 742
– –
136 5962
99 855
– 13
21 –
– 25
– 11
10 –
– 31
– 11
– – –
– – –
193 132 172
– – –
– – –
127 78 98
– – –
– – –
160 6482
113 843
– –
156 6411
117 847
– –
143 6195
111 615
Table 2 Number of dairy herds (n) and cows (n) with different trimming routines in tie stalls and free stalls with concrete or rubber-mat stall base, Norway, 2002 Trimming
Tie stalls
Free stalls
Concrete
Routine Occasional Not at all
Rubber mats
Concrete
Rubber mats
Herds
Cows
Herds
Cows
Herds
Cows
Herds
Cows
16 22 10
303 467 209
6 0 0
121 0 0
17 12 6
541 239 190
4 9 4
110 258 113
2.3. Recruitment and training of personel Fourteen professional claw trimmers attended two courses held by two of the authors. The program was based on acknowledged pedagogical principles and the experience from a pilot study (Fjeldaas et al., 2002). The theoretical and practical teaching included clawtrimming procedures and diagnosis, recording and treatment of claw diseases. All the important aspects of measuring claw length and trimming and recording of diseases were repeated to get a general agreement among the claw trimmers before the initiation of the project. One author also gave individual training to each claw trimmer in one or two herds
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at the project start. A summary of the observations and any ambiguities was sent to all claw trimmers. 2.4. Recording of data The cows were trimmed once within the period from the 1st of January 2002 to summer let out onto pasture. The last trimming was performed the 28th of June. Twelve trimmers used electric grinders with hard-metal abrasive discs, one used a hard-metal bladed disc and one used blade and mallet. Lameness was assessed when the animal was moved to the trimming chute. The criteria for recording of lameness and claw lesions being present (Table 3) were adapted from Bergsten (2000). If there was no lameness or claw lesion, no notation was made. Other abscesses, interdigital phlegmones, horizontal or vertical fissures, interdigital hyperplasias, double soles, under-run heels and papillomatous dermatitis were recorded as ‘‘other findings’’. The dorsal-wall length was measured with a slide gauge on the right lateral front and hind claws from the coronary band along the dorsal border to the apex of the claw. Abnormal claw shapes (including asymmetric and corkscrewed claws) were also recorded. Corkscrewed claws included both mild cases where the abaxial wall was bent inwards with a curved dorsal border and serious cases of corkscrew claws where the abaxial wall was part of the weight-bearing surface. The lengths of corkscrewed claws were not measured. 2.5. Data handling and statistical analyses Data recorded at the farm were transferred to SAS version 8.0 for statistical analyses. Most lesions and abnormal shapes were recorded in hind claws and analyses were performed only on these. Table 3 Definition of lameness and claw lesions recorded at trimming Lesion
Abbreviation
Definition for minimum sign of lesion being present
Lameness
L
Dermatitis
D
Heel-horn erosion
E
Haemorrhages of the white line Haemorrhages of the sole Sole ulcer White-line fissure
HWL
Asymmetric gait, bearing weight on all limbs Superficial, hyperaemic, slightly exudative lesion of the digital/ interdigital skin Slight defects of the horn integrity, pits and small fissures Slight haemorrhagic discoloration
HS
Slight haemorrhagic discoloration
SU WLF
Exposed, unaffected corium Fissure which disappears with deep cut beneath normal trimming level
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Fig. 1. Hind-claw lesions in tie stalls with concrete stall base and free stalls with concrete or rubber-mat stall base and different claw-trimming routines, 95% confidence interval. D: dermatitis, E: heel-horn erosions, HWL: haemorrhages of the white line, HS: haemorrhages of the sole, SU: sole ulcers, WLF: white-line fissures.
The prevalences were calculated for claw lesions and abnormal claw shapes stratified by stall type, trimming routines and the type of trimmer. Calculations of 95% CI for prevalence were based on normal approximation for the binomial proportion except when np or n(1 p) <10. Then absolute values were calculated. A separate cow-level multivariable model was fit for each claw lesion and abnormal claw shape with each lesion and shape as dependent variables using PROC GENMOD with binomial distribution, logit link function and Wald statistics type-3 contrasts. Because some groups contained few animals, the models were stratified on housing and stall base as an
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Table 4a Significant result estimates of the final multivariable models describing routine vs. occasional trimming as to hindclaw lesions and corkscrewed hind claws within housing and stall base, Norwegian diary cows, 2002 Effects
b
S.E.
P
Haemorrhages of the white line (HWL) in tie stalls with concrete stall base. Dfs: 765, deviance: 464.4, delta deviance for trimming routine: 13.0 Intercept 1.98 0.32 <0.001 Months in milk at claw trimming 0.05 0.10 ns Months in milk at claw trimming2 0.0064 0.0092 ns Trimming (routine vs. occasional) 1.03 0.40 <0.01 Random effect of herd (a1) 0.88 0.20 <0.001 Corkscrewed claws (Cork) in tie stalls with concrete stall base. Dfs: 690, deviance: 211.25, delta deviance for trimming routine: 7.13 Intercept 2.76 0.38 <0.001 a Parity 1 0.95 0.55 a Parity 2 0.61 0.39 Parity >2 – – – Trimming (routine vs. occasional) 1.29 0.55 <0.05 Random effect of herd (a1) 0.76 0.36 <0.05 Dermatitis (D) in free stalls with rubber-mat stall base. Dfs: 364, deviance: 160.76, delta deviance for trimming routine: 5.26 Intercept 2.59 0.53 <0.001 Months in milk at claw trimming 0.12 0.08 ns 0.0093 0.0047 <0.05 Months in milk at claw trimming2 Trimming (routine vs. occasional) 1.69 0.68 <0.05 Random effect of herd (a1) 1.07 0.71 ns Heel-horn erosions (E) in free stalls with rubber-mat stall base. Dfs: 364, deviance: 499.46, delta deviance for trimming routine: 7.3 Intercept 0.95 0.68 ns Months in milk at claw trimming 0.083 0.081 ns 0.0045 0.0093 ns Months in milk at claw trimming2 Trimming (routine vs. occasional) 0.77 0.27 <0.01 Random effect of herd (a1) 1.53 0.35 <0.001 Random effect of claw trimmer (a2) 1.55 0.57 <0.01 a
Within same letter P < 0.01.
alternative to including interaction terms. Trimming routine, lactation stage at trimming and parity were included as fixed effects. Trimming was classified as routine, occasional or no trimming at all. Lactation stage was made continuous and used both as linear and square independent variable. Parity was classified as 1, 2 and >2. Only the independent variables and the random effect of herd and claw trimmer were included when found significant for the same claw lesions by Sogstad et al. (2005a,b). These random effects were expressed as a1 and a2 by using the LOGOR statement. Each model was evaluated by deviance and delta deviance with and without the fixed effect of claw trimming (Dohoo et al., 2003). No elimination procedure was performed despite lack of significance for the fixed or random effect variables. A separate mixed model was run for hind-claw length. The model included trimming routine as fixed effect and herd and claw trimmer as random effects.
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The agreement between asymmetric-or corkscrewed hind claws and lameness/hind claw lesions at claw-level was calculated on binary scores using Kappa-analyses (Altman, 1991). k was calculated with 95% confidence interval.
3. Results 3.1. Claw lesions In tie-stall herds with routine trimming 39.9% (95% CI; 35.2, 44.5) of the cows had one or more lesions or abnormal shapes in front or hind claws versus 52.8% (49.0; 56.6) in herds with no routine. In free-stall herds with routine trimming 76.8% (73.6; 80.1) of the cows had one or more lesions or abnormal shapes in front or hind claws versus 68.9% (65.7; 72.1) in herds with no routine. Hind-claw prevalences are in Fig. 1. Significant results based on multivariable-model analyses are in Tables 4a–4c and Table 5. No difference between herdsmen and professional trimmers as to the prevalence of claw lesions was revealed in the multivariable models. Table 4b Significant result estimates of the final multivariable models describing routine vs. no trimming as to hind-claw lesions within housing and stall base, Norwegian diary cows, 2002 Effects
b
S.E.
P
Heel-horn erosions (E) in tie stalls with concrete stall base. Dfs: 508, deviance: 240.9, delta deviance for trimming routine: 1.5 Intercept 1.77 0.51 <0.001 Months in milk at claw trimming 0.16 0.11 ns 0.02 0.01 0.06 Months in milk at claw trimming2 Trimming (routine vs. no) 0.97 0.45 <0.05 Random effect of herd (a1) 2.99 0.68 <0.001 Random effect of claw trimmer (a2) 2.53 1.00 <0.05 Haemorrhages of the white line (HWL) in free stalls with concrete stall base. Dfs: 726, deviance: 565.9, delta deviance for trimming routine: 19.3 Intercept 2.87 0.56 <0.001 Months in milk at claw trimming 0.24 0.11 <0.05 0.031 0.012 <0.01 Months in milk at claw trimming2 Trimming (routine vs. no) 1.22 0.55 <0.05 Random effect of herd (a1) 0.56 0.24 <0.05 Haemorrhages of the sole (HS) in free stalls with concrete stall base. Dfs: 726, deviance: 666.4, delta deviance for trimming routine: 31.9 Intercept 3.31 0.48 <0.001 Months in milk at claw trimming 0.69 0.14 <0.001 0.073 0.013 <0.001 Months in milk at claw trimming2 Parity 1 0.37 0.27 ns Parity 2 0.13 0.20 ns Parity >2 – – – Trimming (routine vs. no) 1.26 0.48 <0.01 Random effect of herd (a1) 0.34 0.15 <0.05
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Table 4c Significant result estimates of the final multivariable models describing occasional vs. no trimming as to hind-claw lesions within housing and stall base, Norwegian diary cows, 2002 Effects
b
S.E.
P
Haemorrhages of the white line (HWL) in tie stalls with concrete stall base. Dfs: 671, deviance: 413.0, delta deviance for trimming routine: 14.2 Intercept 3.25 0.65 <0.001 Months in milk at claw trimming 0.021 0.11 ns Months in milk at claw trimming2 0.0046 0.0094 ns Trimming (occasional vs. no) 1.36 0.60 <0.05 Random effect of herd (a1) 0.93 0.21 <0.001 Sole ulcers (SU) in tie stalls with concrete stall base. Dfs: 671, deviance: 174.1, delta deviance for trimming routine: 6.6 Intercept 5.31 0.75 <0.001 Months in milk at claw trimming 0.50 0.28 0.07 0.057 0.035 0.10 Months in milk at claw trimming2 Trimming (occasional vs. no) 1.69 0.67 <0.05 Random effect of herd (a1) 0.64 0.41 0.11 Haemorrhages of the white line (HWL) in free stalls with concrete stall base. Dfs: 419, deviance: 273.5, delta deviance for trimming routine: 14.0 Intercept 2.96 0.76 <0.001 Months in milk at claw trimming 0.42 0.27 ns 0.057 0.026 <0.05 Months in milk at claw trimming2 Trimming (occasional vs. no) 1.15 0.60 <0.05 Random effect of herd (a1) 0.47 0.19 <0.05 White-line fissures (WLF) in free stalls with concrete stall base. Dfs: 427, deviance: 265.4, delta deviance for trimming routine: 14.0 Intercept 2.97 0.52 <0.001 Trimming (occasional vs. no) 1.13 0.59 <0.05 0.57 0.24 <0.05 Random effect of herd (a1)
3.2. Claw shapes Hind-claw lengths are in Fig. 2 and results based on mixed-model analyses are in Table 6. Prevalences of cows with asymmetric and corkscrewed hind claws are in Fig. 3. Multivariable-model analyses revealed no significant difference between trimming routines for asymmetric hind claws. However, more cows had corkscrewed hind claws in tie stalls with concrete stall base and occasional versus routine trimming (Table 4a and Table 5). No difference between herdsmen and professionals as to the prevalence of abnormal claw shapes was revealed in the multivariable models. We found only poor prevalence agreements between claw shapes and the various lesions; the largest was that for corkscrewed hind claws and haemorrhages of the sole (k = 0.14; 95% CI: 0.10, 0.18).
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Table 5 Significant odds ratios (OR) of the multivariable models for different claw-trimming routines as to hind-claw lesions and corkscrewed hind claws within housing and stall base, 95% confidence interval (CI), Norwegian diary cows, 2002 Type of housing and stall base
Claw lesion
Occasional vs. routine trimming
No vs. routine trimming
No vs. occasional trimming
OR
CI
OR
CI
OR
CI
Tie stalls with concrete stall base
E HWL SU Cork
– 2.8 – 3.6
– 1.3; 6.1 – 1.2; 10.7
2.6 – – –
1.1; 6.4 – – –
– 0.3 0.2
– 0.1; 0.8 0.05; 0.7
Free stalls with concrete stall base
HWL HS WLF
– – –
– – –
0.3 0.3 –
0.1; 0.9 0.1; 0.7 –
0.3 – 0.3
0.1; 1.0 – 0.1; 1.0
Free stalls with rubber-mat stall base
D E
5.4 0.5
1.4; 21.0 0.3; 0.8
D: dermatitis; E: heel-horn erosions; HWL: haemorrhages of the white line; HS: haemorrhages of the sole; SU: sole ulcers; WLF: white-line fissures; Cork: corkscrewed claws.
Fig. 2. Hind-claw length in tie stalls and free stalls with concrete or rubber-mat stall base and different trimming routines, 95% confidence interval.
3.3. Lameness In tie stalls the prevalence of lameness was 0.7% both in herds with routine trimming and herds with no routine. In free stalls the prevalence of lame cows was 2.0% with routine trimming and 1.1% with no routine. The difference was not significant.
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Table 6 Results of final mixed models describing hind-claw length as to claw-trimming routines within housing and stall base, Norwegian diary cows, 2002 S.E.
P
Percentage
Tie stalls with concrete stall base (972 cowsb) Intercept 78.6 Routine trimming 3.2 Occasional trimming 1.8 No trimming at all – Random effect of herd – Random effect of claw trimmer –
Effects
b
2.1 2.0 1.9 – – –
<0.001 ns ns – – –
– – – – 14 23
Tie stalls with rubber-mat stall base (121 cowsb) Intercept 97.3 Random effect of herd – Random effect of claw trimmer –
4.2 – –
<0.001 – –
– 29 22
3.4 3.68 3.97 –
<0.001 ns ns –
– – – – 37 11
2.6 3.67 3.11 – – –
<0.001
– – – – 23 0
Free stalls with concrete stall base (956 cowsb) Intercept 83.6 Routine trimming 0.33 Occasional trimming 1.83 No trimming at all – Random effect of herd Random effect of claw trimmer Free stalls with rubber-mat stall base (472 cowsb) Intercept 82.8 Routine trimming 5.77 Occasional trimming 3.21 No trimming at all – Random effect of herd – Random effect of claw trimmer – a b
a a
– – –
Within same letter P < 0.01. The claw length of corkscrewed claws were not measured and altogether 30 cows are missing.
Fig. 3. Abnormal hind-claw shapes in tie stalls with concrete stall base and free stalls with concrete or rubber-mat stall base and different trimming routines, 95% confidence interval.
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4. Discussion 4.1. Representativeness Although the most-recent claw-trimming routines in the study population were not known at the sampling stage, we assumed the distribution of trimming routines to be representative for Norwegian dairy herds. We imposed the herd-size eligibility criterion to assure that we got several cows per herd, and because the herd size is increasing in Norway. All losses and drop-outs occurred before the statistical analyses. Differences in recording between claw trimmers might have biased our results. One person doing all the recordings was considered, but none had the time to visit all herds. Fewer claw trimmers would have lead to one trimmer having a very large influence on the outcome. The lack of significant cluster effect within claw trimmer except for heel-horn erosions, asymmetric claws and claw length indicates that the inter-observer variability was satisfactory. A test to evaluate sensibility and specificity of trimmer-recordings based on diagnosis of claw lesions on slides was considered but not performed, because simulation of the field situation was impossible. Although we expected that the mostimportant lesions were recorded, we realised as reported by Manske (2003), that particularly mild lesions might have been underreported in our study. The interval since last routine trimming was 6–12 months in most herds. This might have influenced the evaluation of different claw-trimming routines. If the assessment had been performed in the autumn, however, there would have been a large effect of pasture. Our aim was to evaluate different trimming routines in tie stalls and free stalls, and consequently the cows had to be housed for a certain time in advance. In epidemiological studies there will always be the uncertainty around causal mechanisms. What makes the herdsmen decide to trim their cows? Long claws were probably a major reason for trimming. Cows in tie stalls with rubber-mat stall base had the longest claws and all were trimmed routinely. Because normal claw shape is no guarantee for healthy claws the sample of cows chosen for occasional trimming probably did not include all cows that needed to be trimmed. Another reason for trimming might have been many lame cows. However, a 2% prevalence of lame cows was probably not the main reason for initiating routine trimming, although we assume that not all lame cows were detected in our study and that the real prevalence of lameness was higher. Many cows with heel-horn erosions might also have been a reason for trimming. Unless heel-horn erosions are serious with secondary pododermatitis, there will usually be no lameness. Bad odour and the obvious fissures at the bulb of the heel might, however, initiate claw trimming. 4.2. Statistical analyses The data material was too small to run complete models with all interactions for some of the groups, and models were fit for each combination of trimming with housing and stall base. Separate models were more robust. Only models for groups with a sufficient number of observations were included. Due to little power in the separate models we included the fixed effects that were significant for the specified dependent variables in the paper of
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Sogstad et al. (2005a), even when not significant in the particular model. We expected the same associations in these analyses because the material was almost equal. Due to many separate models being evaluated, the interpretation of P-values >0.01 should be done with care to avoid type-1 error. The material was, however, rather small and too low limits for significance would have increased the type-2 error rate. 4.3. Claw lesions 4.3.1. Heel-horn erosions and dermatitis Fewer cows with heel-horn erosions in tie stalls with concrete stall base and routine trimming versus no trimming might have been a positive effect of claw trimming. The reason for more heel-horn erosions and less dermatitis in free stalls with routine versus occasional trimming is not obvious. The difference being significant in free stalls with rubber mats and not in stalls with concrete might have been a consequence of longer claws with routine versus occasional trimming in stalls with rubber mats, but not on concrete. Improper trimming resulting in low heels and increased pressure on the heel and the bulb might have predisposed the routinely trimmed claws to heel-horn erosions. However, more heel-horn erosions might have been an incitement to routine trimming. There is no plausible explanation for the corresponding low prevalence of dermatitis. Somers (2004) found that claw-trimming intervals >7 months were related to more digital dermatitis, interdigital dermatitis and heel-horn erosions in free stalls; Manske et al. (2002) found that dermatitis and heel-horn erosions were most prevalent in the spring even if the animal had been trimmed the autumn before. This might imply that there is only a brief preventive effect of claw trimming on dermatitis and heel-horn erosions, and that trimming intervals >6 months are too long in free stalls. Enevoldsen et al. (1991b) found that high daily milk yields were associated with high risk of heelhorn erosions. Low prevalence of heel-horn erosions and the lowest daily milk yields being found in herds with no trimming at all in our study indicates that feeding intensity influenced the need for claw trimming. A secondary effect of low-intensity feeding is drier manure and consequently a cleaner environment, which we expect to prevent infectious claw lesions. Poor hygiene (Philipot et al., 1994) and dirty cows (Sogstad et al., 2005a) are risk factors for heel-horn erosions. 4.3.2. Haemorrhages of the white line and the sole Occasional claw trimming being related to haemorrhages of the white line in tie stalls with concrete stall base might indicate no preventive effect and a need for routine trimming. Probably, only cows with long claws, abnormal claw shapes or lameness were trimmed previously and not cows with subclinical claw lesions and low-grade lameness. More haemorrhages in free stalls with concrete stall base and routine trimming versus those with no trimming might be a consequence of uncomfortable cubicles. The lying time on concrete stall base might have been reduced and if trimming was incorrectly performed, the risk for claw lesions would increase. Excessive shortening of the toe, leaving it square ended and removal of the axial wall are the most common faults of trimming (Blowey, 2002) and a thicker sole is required when the cows spend a long time walking on hard surfaces. By physical experiments van der Tool (2004) showed that the sole and bulb of
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recently trimmed claws were subject to the highest pressure. He advised that more weight should be distributed to the wall, which is the strongest part of the claw. It is our experience that many Norwegian trimmers make the dorsal wall too short and the sole too thin. It is also quite common to remove too much of the axial wall. This might explain why no trimming at all was related to fewer haemorrhages of the sole than occasional or routine trimming in free stalls with concrete stall base. Most free stalls had slatted concrete alleys which cause shorter strides, larger step abduction and more asymmetrical walking than on solid floors (Telezhenko et al., 2002). This combined with improper trimming might have increased the risk for bruising of the sole. 4.3.3. Sole ulcers and white-line fissures More sole ulcers in tie stalls and more white-line fissures in free stalls with concrete stall base and occasional versus no trimming at all might be explained by a higher risk for ulcers and also no preventive effect of trimming in occasionally trimmed herds. That routine trimming was not significantly better than occasional trimming might have been a consequence of too long time since last trimming. At spring trimming Manske et al. (2002) found that the prevalence of lesions associated with laminitis and the need for acute treatments between scheduled trimmings were reduced by additional autumn trimming. However, by annual claw trimming Burgi (1998) reduced sole ulcers and white-line diseases to less than 2%. Because there was no difference between professional trimmers and herdsmen in our study it might be questioned if the mostrecent trimmings were performed with the necessary skills. It is our experience that many Norwegian herdsmen have inadequate trimming technique. This is probably a consequence of small herds and little practice. Enevoldsen et al. (1991a) found that low milk yield alone and high milk yield combined with high body weight were important risk factors for sole ulcers in lactation 1, whereas low milk yield combined with high body weight was important in later lactations. Lowest prevalence of sole ulcers and lowest milk yields in tie stalls with no trimming at all in our study emphasizes that milk yield influences the need for claw trimming. The reason might be that nutrition influences the horn’s growth rate (van Amstel and Shearer, 2001) and the risk for clawhorn disruption (Hoblet and Weiss, 2001). 4.4. Claw shapes 4.4.1. Length of the dorsal wall Shorter claws with occasional versus routine trimming in free stalls with rubber-mat stall base might explain why routine trimming was not performed. The result indicates that equilibrium between growth and wear had been established for cows not trimmed. The horn of the wall grows at a rate of 5 mm per month, with a range of 0.2–8.5 mm and the horn of the sole grows at the rate of 3 mm per month (van Amstel and Shearer, 2001). Hahn et al. (1986) found that the monthly dorsal-wall growth rate during first lactation was 6.6 mm for hind claws, and Logue et al. (1993) concluded that the claws quickly return to their ‘‘pre-trim’’ look. Manson and Leaver (1988) found that trimming increased claw-horn growth. This might partly explain why longer claws were recorded in some herds with routine trimming.
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4.4.2. Asymmetric and corkscrewed claws More corkscrewed claws recorded in tie stalls with concrete stall base and occasional versus routine trimming indicate that routine trimming was preventive. However, routine trimming did not prevent corkscrewed hind claws in free stalls in our study. That the cow is moving in a much more complex environment in free stalls might have a greater impact on claw shape than trimming once or twice a year. We assume that corrective trimming of corkscrewed claws is not as long-lasting in free stalls as in tie stalls and that trimming intervals <6 months are probably required. Because we expect professionals to perform trimming of higher quality than herdsmen, no difference between herdsmen and professional trimmers for abnormal claw shapes indicates that the professionals’ technique was not optimal. Poor agreement between abnormal claw shapes and most claw lesions confirms that claw lesions often occur independently of abnormal claw shape. However, the agreement between corkscrewed hind claws and haemorrhages of the sole partly agrees with van Amstel et al. (2002a) who stated that haemorrhages of the white line and the sole, whiteline separations and sole ulcers are commonly observed in corkscrew claws. 4.5. Lameness Low prevalence of lameness in our study probably explains why no significant difference between the trimming routines in neither tie nor free stalls was revealed. Manson and Leaver (1988) found that preventive trimming reduced both lameness and the duration of claw diseases. Logue et al. (1993) stated that regular claw trimming will not ‘‘stop’’ lameness but that it ‘‘helps’’. 4.6. Trimming interval and technique Long intervals since last trimming in the study herds indicate long trimming intervals which might have been a reason for small or no benefits of routine trimming in free stalls. However, there were equally long intervals in tie stalls and most lesions and abnormal claw shapes in those herds seemed to benefit from routine claw trimming. Our results might indicate that the routine-trimming intervals in free stalls, to a larger extent than in tie stalls, have to be adjusted for the individual herd. Huber et al. (2004) found that functional claw trimming every 6-months improved claw health both in tie stalls and free stalls. Type of stall base and type of alleys were not reported. However, Huang et al. (1995) found that a 4months trimming interval was worse than longer intervals for heel-horn erosions, interdigital dermatitis, laminitis and white-line separation, but not for sole ulcers and corkscrew claws. The type of housing was not reported in the study. No difference between professionals and herdsmen in our study indicates that the mostrecent trimmings were not performed with the necessary skills. Nu¨ske (1998) found that the incidence of serious claw diseases was decreased after functional claw trimming was introduced. Vermunt (1999) emphasized that functional claw trimming can improve locomotion and restore claw shape, but only if carried out correctly. Another study concluded that biological resilience to mechanical forces might be impaired by inappropriate claw trimming (Webster, 2002).
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5. Conclusion Our study suggests that routine claw trimming prevents claw disorders in Norwegian tie stalls while occasional trimming has minor preventive effect. Low prevalence of claw disorders despite no trimming at all in tie-stall herds with low milk yield indicates a decreased need for claw trimming in these herds. Our study also indicates that routine claw trimming in Norwegian free stalls has not had the desired preventive effects.
Acknowledgements We are grateful to the participating claw trimmers and farmers, as well as Stig Larsen, Norwegian School of Veterinary Studies, for his statistical support and ideas. The study was funded by TINE Norwegian Dairies BA, GENO Breeding and A.I. Association, Norwegian Meat Research Centre and The Research Council of Norway. Access to data was given by the Norwegian Dairy Herd Recording System and the Norwegian Cattle Health Services in agreement number 6/2001 by 19.09.2001.
References Altman, D.G. (Ed.), 1991. Practical Statistics for Medical Research. Chapman & Hall/CRC, London. Bergsten, C., 2000. Workshop report about the documentation of claw diseases. Part 2. In: Mortellaro, C.M., De Vecchis, L., Brizzi, A. (Eds.), Proceedings of the 11th International Symposium on Disorders of the Ruminant Digit, Parma, pp. 12–16. Bergsten, C., Hultgren, J., Manske, T., 1998. Claw traits and foot lesions in Swedish dairy cows in relation to trimming interval and housing system. A preliminary report. In: Lischer, C.J., Ossent, P. (Eds.), Proceedings of the 10th International Symposium on Lameness in Ruminants, Lucerne, pp. 46–48. Blowey, R.W., 2002. Claw trimming-how should it be done? A comparison of two approaches. In: Shearer, J.K. (Ed.), Proceedings of the 12th International Symposium on Lameness in Ruminants, Orlando, pp. 122– 126. Burgi, K., 1998. Determine maintenance hoof trimming by observing movement. In: Lischer, C.J., Ossent, P. (Eds.), Proceedings of the 10th International Symposium on Lameness in Ruminants, Lucerne, pp. 20– 22. Dohoo, I., Martin, W., Stryhn, H., 2003. Veterinary Epidemiologic Research. In: McPike, S.M. (Ed.), AVC Inc. Charlottetown, Transcontinental Prince Edward Island. Enevoldsen, C., Gro¨hn, Y.T., Thysen, I., 1991a. Sole ulcers in dairy cattle: associations with season, cow characteristics, disease, and production. J. Dairy Sci. 74, 1284–1298. Enevoldsen, C., Gro¨hn, Y.T., Thysen, I., 1991b. Heel erosion and other interdigital disorders in dairy cows: associations with season, cow caracteristics, disease, and production. J. Dairy Sci. 74, 1299–1309. Fjeldaas, T., Forshell, K.P., Østera˚s, O., 2002. Monitoring claw diseases in the Norwegian cattle population. In: Shearer, J.K. (Ed.), Proceedings of the 12th International Symposium on Lameness in Ruminants, Orlando, pp. 329–332. Hahn, M.V., McDaniel, B.T., Wilk, J.C., 1986. Rates of hoof growth and wear in Holstein cattle. J. Dairy Sci. 69, 2148–2156. Hoblet, K.H., Weiss, W., 2001. Metabolic hoof horn disease: claw horn disruption. Vet. Clin. N. Am. Food Anim. Pract. 17, 111–127. Huang, Y.C., Shanks, R.D., McCoy, G.C., 1995. Evaluation of fixed factors affecting hoof health. Livest. Prod. Sci. 44, 115–124.
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Huber, J., Stanek, C., Troxler, J., 2004. Effects of regular claw trimming in different housing systems. In: Zemljic, B. (Ed.), Proceedings of the 13th International Symposium on Lameness in Ruminants, Maribor, pp. 116– 117. Kloosterman, P., 1997. Claw care. In: Greenough, P.R., Weaver, A.D. (Eds.), Lameness in Cattle, third ed. W.B. Saunders Company, Philadelphia, pp. 123–142. Logue, D.N., Offer, J.E., Kempson, S.A., 1993. Lameness in dairy cattle. Ir. Vet. J. 46, 47–58. Manske, T., Hultgren, J., Bergsten, C., 2002. The effect of claw trimming on the hoof health of Swedish dairy cattle. Prev. Vet. Med. 54, 113–129. Manske, T., 2003. Om klo¨vva˚rdares klo¨vhaˆlsoregistreringar. (Claw health recordings by claw trimmers) Sven. Vet. Tidn. 15, 11–18. Manson, F.J., Leaver, J.D., 1988. The influence of dietary protein intake and of hoof trimming on lameness in dairy cattle. Anim. Prod. 47, 191–199. Manson, F.J., Leaver, J.D., 1989. The effect of concentrate: silage ratio and hoof trimming on lameness in dairy cattle. Anim. Prod. 49, 15–22. Nu¨ske, S., 1998. Functional trimming of the claw—experiences and influences on veterinary treatment after three years of practice at the experimental farm of Oberschleissheim, University of Munich. (Poster). In: Lischer, C.J., Ossent, P. (Eds.), Proceedings of the 10th International Symposium on Lameness in Ruminants, Lucerne, pp. 28–29. Peterse, D.J., Korver, S., Oldenbroek, J.K., Talmon, F.P., 1984. Relationship between levels of concentrate feeding and incidence of sole ulcers in dairy cattle. Vet. Rec. 115, 629–630. Philipot, J.M., Pluvinage, P., Cimarosti, I., Sulpice, P., Bugnard, F., 1994. Risk factors of dairy cow lameness associated with housing conditions. Vet. Res. 25, 244–248. Shearer, J.K., van Amstel, S.R., 2001. Functional and corrective claw trimming. Vet. Clin. N. Am. Food Anim. Pract. 17, 53–72. Shearer, J.K., van Amstel, S.R., 2004. Claw health management and therapy of infectious claw diseases. In: Kaske, M., Scholz, H., Ho¨lterschinken, M. (Eds.), Recent developments and perspectives in bovine medicine: keynote lectures from the 22nd World Buiatric Congress, Hannover, 2002, pp. 258–267. ˚ .M., Fjeldaas, T., Østera˚s, O., 2005a. Lameness and claw lesions of the Norwegian Red diary cattle Sogstad, A housed in free stalls in relation to environment, parity and stage of lactation. Acta Vet. Scand. 46, 203–217. ˚ .M., Fjeldaas, T., Østera˚s, O., Forshell, P.K., 2005b. Prevalence of claw lesions in Norwegian dairy Sogstad, A cattle housed in tie stalls and free stalls. Prev. Vet. Med. 70, 191–209. Somers, J., 2004. Claw disorders and disturbed locomotion in dairy cows: the effect of floor systems and implications for animal welfare. Ph.D. thesis. University of Utrecht, Utrecht. Telezhenko, E.V., Bergsten, C., Manske, T., 2002. Cow locomotion on slatted and solid floors assessed by trackway analysis (Poster). In: Shearer, J.K. (Ed.), Proceedings of the 12th International Symposium on Lameness in Ruminants, Orlando, pp. 417–419. Toussaint Raven, E., 1989. Cattle Foot Care and Claw Trimming. Farming Press, Ipswich. van Amstel, S.R., Palin, F.L., Shearer, J.K., 2002a. Application of functional trimming procedures to corkscrew claws. In: Shearer, J.K. (Ed.), Proceedings of the 12th International Symposium on Lameness in Ruminants, Orlando, pp. 99–108. van Amstel, S.R., Palin, F.L., Shearer, J.K., 2002b. Claw trimming: an adaption of the Dutch method. In: Shearer, J.K. (Ed.), Proceedings of the 12th International Symposium on Lameness in Ruminants, Orlando, pp. 127– 130. van Amstel, S.R., Shearer, J.K., 2001. Abnormalities of hoof growth and development. Vet. Clin. N. Am. Food Anim. Pract. 17, 73–91. van der Tool, P.P.J., 2004. Biomechanical aspects of the claw—floor interaction in dairy cattle. Implications for Locomotion and Claw Disorders. Ph.D. Thesis. University of Utrecht, Utrecht. Vermunt, J., 1999. Regular claw trimming for the control of lameness—good or bad? Vet J. 157, 109–110. Ward, W.R., 1999. Lameness in dairy cattle—an overview. Cattle Pract. 7, 333–340. Webster, J., 2002. Effect of environment and management on the development of claw and leg diseases. In: Kaske, M., Scholz, H., Ho¨ltershinken, M. (Eds.), Recent developments and perspectives in bovine medicine: keynote lectures from the 22nd World Buiatrics Congress, Hannover, pp. 248–256.