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Analysis of relationships between veterinary recorded production diseases and milk production in dairy cows
Livestock Production Science, 23 (1989) 67-78
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Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
Analysis of Relationships between Veterinary Recorded Production Diseases and Milk Production in Dairy Cows 0. DISTL, A. WURM, A. GLIBOTIC, G. BREM and H. KRAU£LICH
Institut f~r Tierzucht und Tierhygiene der Universitiit Mi~nchen, Veteriniirstrafle 13, D-8000 Mi~nchen 22 (Federal Republic o[ Germany) (Accepted for publication 5 April 1989)
ABSTRACT Distl, 0., Wurm, A., Glibotic, A., Brem, G. and Kr~iuglich, H., 1989. Analysis of relationships between veterinary recorded production diseases and milk production in dairy cows. Livest. Prod. Sci., 23: 67-78. Veterinary diagnoses were used to estimate the relationships between various disease frequencies and milk production of the cow and the herd. For the analysis, diseases were registered in a veterinary practice. Records of a total of 1686 German Simmental (DFV) cows and 2178 German Brown Swiss (DBV) cows were used in a least squares model with the following effects: breed, lactation number, month of calving, herd effects (disease frequency, milk production), milk production of the cow. Metabolic disease frequencies (ketosis, milk fever, all metabolic diseases) were related positively to 305-day milk yield of the cow and were significant for DBV (r=0.07-0.12), but for DFV correlations were near zero (r=0.02-0.04). For udder diseases (acute and chronic mastitis, injuries of the udder), the associations with 305-day milk yield were near zero. In reproductive disorders (retained placenta, endometritis, anoestrus, ovarian cysts), only the frequency of ovarian cysts had a significant positive correlation with 305-day milk yield of the cows in both breeds (DFV: r=0.08; DBV: r=0.13). With increasing herd milk production, disease frequencies decreased for metabolic and reproductive disorders. It can be concluded that increasing milk yield of the cows leads to an increase in the frequencies of certain diseases. However, better feeding and management in high producing herds counterbalanced the negative effect of high milk production of cows on disease occurrence.
INTRODUCTION
Besides milk production, secondary traits like fertility and susceptibility to diseases alter the efficiency of dairy cattle production and affect the profit. High-yielding dairy cows could be more susceptible to production diseases in this way reducing the income from their milk. On the other hand, high yielding herds could decrease their disease frequencies by good management to a higher 0301-6226/89/$03.50
© 1989 Elsevier Science Publishers B.V.
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O. DISTL ET AL.
extent than low yielding herds. Therefore, cows yielding the same milk production, but kept in herds with different milk production levels, might not be comparable in their production disease frequencies. Discussing the associations between milk production and production disease frequencies, two components have to be taken into account, the individual component of the cow and the herd effect. The objective of our study is to analyse the relationships between the most frequent veterinary diagnosed and treated production diseases and milk production, based on the individual records of the cows and on the herd averages. MATERIAL AND METHODS
Diagnoses and treatments of cows were recorded in one veterinary practice. A detailed description of the recording of disease data is given elsewhere (Brem, 1982; Wurm, 1985; Glibotic, 1986). The recording period started in April 1982 and ended in March 1983. A survey on the frequency of some veterinary diagnoses and on the milk production data of the analysed material is given in Table 1. The milk recording statistics are in good agreement with figures of 305-day milk production of the region in which the veterinary practice is situated. Of all registered diagnoses, only the diagnoses of major importance were analysed. A cow was considered as diseased, if the disorder was diagnosed or treated at least once during the first 4 months after calving. This restriction might influence only these disease frequencies which are not related to the postpartum period. However, most metabolic, udder and fertility disorders occur within the first months after calving. TABLE 1 Distribution of veterinary diagnoses and average 305-day milk production of cows (n = 3864 ) and herds (n= 186) German Simmenml(DFV)
Brown Swiss(DBV)
Cows
Herds
Cows
Herds
n
1686
110
2178
111
Frequency (%) of Metabolic disorders Udder disorders Fertility disorders
4.6 4.8 16.1
5.2 4.8 15.7
5.0 7.8 13.5
4.7 7.2 13.7
Milk yield (kg) Fat content (%) Protein content (To)
4733 _+945 3.86 _+0.32 3.33 _+0.19
4273 _+559 3.85 _+0.17 3.32 _+0.10
5104-+_1070 3.85 _+0.32 3.31 _+0.19
4613 ___625 3.83 _+0.16 3.31 _+0.10
RELATIONSHIPS BETWEEN DISEASES AND MILK PRODUCTION
69
In the statistical analysis, only data from cows under milk recording are included. In some herds, cows of both breeds, German Simmental (DFV) and Brown Swiss (DBV), were kept and in this case herd averages were computed separately for each breed. The following disease frequencies, based on veterinary recordings, were analysed: Metabolic disorders: milk fever; ketosis; all metabolic diseases. Udder disorders: mastitis; acute mastitis; chronic mastitis; injuries of teats and udder. Fertility disorders: retained placenta; endometritis; anoestrus; ovarian cysts. All metabolic diseases comprise all veterinary diagnosed or treated metabolic diseases, e.g., milk fever, ketosis, hypomagnesaemia, osteomalacia, etc. Concerning the diagnosis of mastitis, all cases of acute and chronic mastitis are included. Under the diagnosis of endometritis the following uterus disorders are included: abnormal lochia; endometritis; metritis; pyometra. Anoestrus is used as a symptomatic diagnosis and may also be due to acyclia or persistent corpus luteum. Milk production parameters (305-day lactation and average milk production of the first three milk recordings after calving) were milk yield (kg), fat content (%), protein content (%) and maximum daily milk yield (kg). The following statistical model for the all-or-none disease parameters was employed: Yijk~mno=/~+Ai +By + Ck +b(HM-D~:i) + b(HM-Yml:i) +b(HM-Fm2:i) + b ( HM-Pm3:i ) + b ( CO- Ynl:i ) + b ( eO-Fn2:i ) + b ( CO-Pn3:~) + %ktmno where/~ = intercept; A~= fixed effect of breed i (i-- 1,2);Bj = fixed effect of lactation number j ( j = l - 7 ) ; Ch=fixed effect of calving month k ( k = l - 1 2 ) ; b= linear regression coefficient; HM-Dt:i= herdmate average for the disease frequency being analysed within breed i; H M - Yml:i = herdmate average for milk yield within breed i; HM-Fm2:i = herdmate average for fat content within breed i; HM-Pm3:i=herdmate average for protein content within breed i; COYnx:i = milk yield of the cow within breed i; CO-F~2:~= fat content of the cow's milk production within breed i; CO-Pn3:~=protein content of the cow's milk production within breed i; e~ih~o= random residual effect; Y~jkLm~o= not diSeased or diseased cow (0/1). The all-or-none parameters were analysed as quasi-continuous traits. Quadratic and cubic regression coefficients for herdmate averages and for cow milk production were meaningless and could therefore be neglected. Milk yield, fat and protein content could be regarded in the model simultaneously because there were no indications of a multicollinearity problem. From the statistical viewpoint, non-linear probability models might be more appropriate than the linear probability model employed, but simulation studies and application to
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O. DISTLET AL.
field data showed that the benefits of the non-linear probability model are rather limited (Distl, 1985; Meijering and Gianola, 1985). RESULTS
The relative contribution (%) of important systematic influences on disease frequencies to the total explained variance by the applied model are shown in Table 2. The accounted variance of the whole model (R 2) varied between 2.3 and 18.2%, depending on the analyged disease frequency. The most important systematic influence was the herd effect. About 30-80% of the total explained variance was accounted for by the herdmate average of disease frequency. A seasonal pattern for the incidence of ketosis could be found. Ketosis occurred more frequently in the winter months than in the other months of the year. A significant influence of the calving m o n t h on mastitis was observed, but no clear seasonal pattern was evident. As expected, lactation number exerted a significant influence on the occurrence of milk fever. During the first three lactations, only very few cases of milk fever were diagnosed. The highest frequency of milk fever (9.5%) was found in the sixth lactation. Metabolic disorders were more frequent in DBV than in DFV, whereas udder and fertility disorders occurred more often in DFV than in DBV (Table 3 ), but the LS means for the breeds for all metabolic diseases showed significant difTABLE 2 Explained variance in percent (R 2) of some systematic influences on metabolic, udder and fertility disorders Disorder
Metabolic disorders Milk fever Ketosis All metabolic diseases Udder disorders Mastitis Acute mastitis Chronic mastitis Injuries of teats and udder
Month of calving
Lactation number
Disease frequency of herdmates
R2 (%)
25.9***
41.2"** 73.9*** 72.1"**
11.7 18.2 17.6
72.7*** 71.6"** 74.2*** 32.8***
12.6 10.4 9.4 2.3
78.8*** 66.8* ** 75.7*** 81.2"**
8.2 9.4 13.3 15.8
4.8* 11.4"**
6.9** 8.0**
Fertility disorders Retained placenta Endometritis Anoestrus Ovarian cysts *P< 0.05; **P< 0.01; ***P< 0.001.
RELATIONSHIPS BETWEEN DISEASES AND MILK PRODUCTION
71
TABLE 3 LS means a n d t h e i r s t a n d a r d errors for the breeds G e r m a n S i m m e n t a l ( D F V ) a n d Brown Swiss ( D B V ) in disease frequencies (%) Disorder
DFV
DBV
Metabolic disorders Milk fever Ketosis All metabolic diseases
3.02 ± 1.07 1.09 ± 0.69 3.26 +_ 1.24 a
4.43 ± 1.00 1.74 ± 0.75 6.42 ± 1.17 a
Udder disorders Mastitis Acute mastitis Chronic mastitis Injuries of teats a n d udder
6.92 ± 1.47 3.38 ± 1.15 4.07 _+ 1.13 0.10 _+0.33
6.19 ± 3.12 ± 3.70 ± 0.17 ±
1.39 1.08 1.06 0.31
4.08 ± 1.24 2.31 ± 1.01 3.39 _+1.04 11.71 ± 1.69
3.97 ± 1.74_ 3.00 ± 10.18 ±
1.17 0.94 0.98 1.58
Fertility disorders Retained placenta Endometritis Anoestrus Ovarian cysts
aDifference between breeds: P < 0.05.
ferences only between German Simmental (DFV) and Brown Swiss (DBV) cows. The risk of metabolic diseases for German Brown Swiss cows was nearly twice that of German Simmental cows. The associations between milk production and the occurrence of metabolic, udder as well as fertility disorders were estimated by correlation coefficients and are shown in Table 4. The correlation coefficients indicate that the risk of increasing disease frequency with a higher deviation of milk production from the herdmate average seems rather low. In German Simmental (DFV) cows, only chronic mastitis and ovarian cysts were related significantly to individual milk yield. For German Brown Swiss (DBV) cows, significant associations were found between 305-day milk yield and metabolic disorders, teat injuries and udder as well as ovarian cysts. Also for German Brown Swiss (DBV) cows, the correlations between protein content and metabolic disorders (milk fever, all metabolic disorders) as well as fertility disorders (endometritis, anoestrus, ovarian cysts) were significantly negative. Similar results revealed the correlation analysis between disease frequencies and the average milk production of the first three milk recordings after calving as well as the maximum daily milk yield (Wurm, 1985; Glibotic, 1986). When compared with the individual milk production of the cow, the herdmate average production in milk yield gave regression and correlation coefficients in which the signs were reversed for nearly all analysed diseases. The expected changes in disease frequencies per one standard deviation of 305-day
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o. DISTL ET AL
TABLE 4 Significant correlation coefficients between metabolic, udder, fertility disorders and milk production (305-day lactation) of German Simmental (DFV) and Brown Swiss cows (DBV) Disorder
Milk yield DFV
Metabolic disorders Milk fever Ketosis All metabolic Disorders Udder disorders Mastitis Acute mastitis Chronic mastitis Injuries of teats and udder Fertility disorders Retained placenta Endometritis Anoestrus Ovarian cysts
DBV
0.07* 0.09* 0.12"
Fat c o n t e n t
Protein content
DFV
DFV
DBV
- 0.08* - 0.07* -0.09*
DBV
- 0.08* -0.11"*
0.08* - 0.08*
- 0.07* 0.06* 0.08*
0.13"**
0.06* - 0.06* - 0.06* -0.09**
*P < 0.05; **P < 0.01; ***P < 0.001.
TABLE 5 Expected changes in disease frequencies (%) per one unit of standard deviation in 305-day lac tation milk yield for German Simmental (DFV) and Brown Swiss cows (DBV) Disorder
305-day milk yield DFV
Metabolic disorders Milk fever Ketosis All metabolic disorders Fertility disorders Retained placenta Endometritis Anoestrus Ovarian cysts
DBV Herd
0.73 0.57 1.16
- 1.44 - 0.60 - 1.80
1.01 1.67"* 2.63**
- 1.76" - 0.69 - 2.22*
0.29 1.28 0.89 3.28**
0.45 -0.19 - 0.56 - 1.26
0.93 -0.11 0.90 4.69***
- 1.14 0.34 - 0.76 - 2.61
* P < 0.05; * * P < 0.01; ***P < 0.001.
Cow
Herd
Cow
RELATIONSHIPS BETWEEN DISEASES AND MILK PRODUCTION
73
milk yield of the individual cow and the herd are given in Table 5 for DFV and DBV. The regression coefficients between udder diseases and milk yield were small and are therefore not displayed in the tables. The opposite influences of increasing herdmate milk yield and increasing individual cow milk yield were almost balanced for metabolic disorders, anoestrus and retained placenta. The frequency of ovarian cysts was affected more by the milk yield of the cow than by herdmate milk production. The expected changes with milk yield in the frequency of endometritis differed between the breeds DFV and DBV. DISCUSSION AND CONCLUSIONS
The analysis of systematic effects showed that the herd effect was the most important factor in the incidence of metabolic, udder and fertility disorders. In Norway (Solbu, 1983) and Sweden (Philipsson et al., 1980), the same results were found for ketosis, udder and fertility disorders. The frequency of milk fever increased significantly with parity. Age effects and milk fever occurring in preceding lactations may be predisposing factors for milk fever in later lactations. Culling because of milk fever could lead to a reduction in milk fever with increasing lactation number. The significant effect of month on ketosis can be an indication that nutrition problems play a role in the pathogenesis of ketosis. The explained variance in the analysis of the investigated disease frequencies is smaller in comparison to the analysis of milk production data. This may be due to a large individual influence of the cow on disease occurrence. Significant breed differences were found only for all metabolic diseases. A comparison of the two breeds, DFV and DBV, within herds was not possible. Therefore interactions between herds and breeds can influence the LS means of breeds. The phenotypic relationships between milk production of the cow and disease frequencies were rather low and positive. Nevertheless, the rather low correlations were, in some cases, significantly different from zero. The tendency could be noted that the associations between milk production of the cow and of the herd seemed to be more evident in the breed DBV than in DFV. Analysing the association between milk production and disease frequency, two different aspects can be considered. Diseases often reduce milk production (e.g., Dijkhuizen, 1983). To show the depression of milk yield by disease occurrence was not the objective of this study. On the contrary, it should be analysed if cows with high milk production are exposed to increasing risk of disease occurrence. The milk production parameters used should be appropriate for this purpose because milk recording is usually carried out only in healthy cows and the 100- or 305-day lactation records are estimated as in healthy cows. A slight underestimation of the correlation coefficients could be possible
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O. DISTL ET AL.
if some of the diseased cows were milk recorded. Lactation milk production may also be reduced if diseases lead to permanent organ defects and following the depression of milk production. Using the previous lactation milk production instead of the current lactation has also some disadvantages: first lactating cows must be excluded; diseases might have affected the previous lactation milk production; the interaction between lactation number and milk production is neglected. Breed differences in the correlation analysis between milk production and disease frequencies can be partly caused by the higher average and variation in milk production of DBV in comparison to DFV. Crossbreeding of German Brown Swiss cows with U.S.-Brown Swiss bulls may also be of importance. Further reasons could be management factors because there was no complete overlapping of the different breeds within herds. In most studies, a slight positive phenotypic correlation between the current individual milk yield and ketosis (Norman and Van Vleck, 1972; Martin et al., 1982; Berglund and Larsson, 1983; Solbu, 1983; Kauppinen, 1984; Dfiring, 1987) as well as milk fever (Solbu, 1983; Diiring, 1987) was found. Norman and Van Vleck (1972) estimated positive phenotypic interrelationships between the frequency of ketosis and lifetime performance as well as first lactation milk yield. Analyses using previous milk yield indicated that cows with increasing previous milk yield are at higher risk of occurrence of milk fever (Dohoo and Martin, 1984; GrShn et al., 1986; Bendixen et al., 1987) and ketosis (Martin et al., 1982; Curtis et al., 1985; GrShn et al., 1986). However, Erb et al. (1985) and Curtis et al. (1985) could not confirm the positive associations between previous milk yield and milk fever; also Dohoo and Martin (1984) did not find a positive relationship between ketosis and previous milk yield. Considering the relationships between the frequencies of fertility disorders and current or previous milk yield, almost consistent estimates were reported for cystic ovaries, whereas for retained placenta, endometritis and metritis the estimates are rather inconsistent in the literature. Cows with high milk yield in previous or current lactation seem to be at increasing risk for ovarian cysts (Norman and Van Vleck, 1972; Martin et al., 1982; Shanks et al., 1982; Solbu, 1984; Coleman et al., 1985; Erb et al., 1985 ). Solbu (1984) also found a positive phenotypic correlation between current milk yield of the cow and anoestrus as well as metritis. In contrast to Solbu (1984), previous lactation milk yield was not a risk factor for metritis in the study of Erb et al. (1985) as well as in the analysis of Dohoo and Martin (1984). Retained placenta was associated with lower milk yield of the current lactation in Norwegian Red and White dairy cows (Solbu, 1984), whereas Diiring (1987) found in German Red and White as well as in German Black and White cows positive phenotypic correlations between retained placenta and current milk yield. Inflammations of the reproductive tract may influence current milk production. Therefore, the correlation estimates between milk yield in the same lactation and retained placenta
RELATIONSHIPS BETWEEN DISEASES AND MILK PRODUCTION
75
as well as metritis or endometritis could be biased downwards. The same bias may also influence the correlation between mastitis and milk yield. This may explain to some extent the large variations in phenotypic correlations between these two traits, as reported in literature ( N o r m a n and Van Vleck, 1972; Wilton et al., 1972; LindstrSm and Syv~ij~rvi, 1978; Solbu, 1983; Bunch et al., 1984; Dohoo and Martin, 1984; Erb et al., 1985; Diiring, 1987; Emanuelson et al., 1987). The studies of Dohoo and Martin (1984), Erb et al. (1985) and Emanuelson et al. (1987) indicate that previous milk yield and frequency of mastitis may not be related. These findings are in agreement with the analysis of our data set, in which monthly milk recordings of cows which were diseased at the day of milk recording were not included. In contrast to Solbu (1983) and GrShn et al. (1986), a reduction in the frequencies of metabolic and some fertility disorders was found with increasing herdmate milk yield. It is interesting to note that the relationships between average herdmate milk yield production and fertility parameters also flow in a positive direction (RSsch, 1984). Herd milk production seems to be a good indicator of overall management in our material. Good management prevents metabolic diseases to nearly the same extent as high milk yield predisposes to metabolic diseases. Similar findings are also given for anoestrus in both breeds, DFV and DBV, and retained placenta in DBV. The management influence on ovarian cysts could be shown, but the milk production of the cow seems to be a more important risk factor. Increasing the milk production of cows in the same herd without improving management practices was shown to be a risk factor for metabolic and some fertility disorders. Furthermore, the analysis of the data of the two dual-purpose breeds, German Simmental and Brown Swiss, suggested that the milk production of cows can be increased without the risk of altering profit by higher occurrences of metabolic, udder and some fertility disorders, if management and feeding practices are adjusted for high-yielding cows.
REFERENCES Bendixen, P.H., Vilson, B., Ekesbo, I. and Astrand, D.B., 1987. Disease frequencies in dairy cows in Sweden. III. Parturient paresis. Prev. Vet. Med., 5: 87-97. Berglund, G. and Larsson, K., 1983. Milk ketone-bodies and reproductive performance in post partum dairy cows.V. International Conference on Production Disease in Farm Animals, 1012 August 1983, at Uppsala, Sweden. Brem, G., 1982. Ein System zur Erfassung von Gesundheitsdaten in Milchviehbetrieben und ihre Verarbeitung mit Hilfe tier~irztlicher Praxiscomputer. XIIth World Congress on Diseases of Cattle, Amsterdam, Vol. 1, pp. 609-612. Bunch, K.J., Heneghan, D.J.S., Hibbit, K.G. and Rowlands, G.J., 1984. Genetic influences on clinical mastitis and its relationship with milk yield, season and stage of lactation. Livest. Prod. Sci., 11: 91-104.
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Coleman, D.A., Thayne, W.V. and Dailey, R.A., 1985. Factors affecting reproductive performance of dairy cattle. J. Dairy Sci., 68: 1793-1803. Curtis, C.R., Erb, H.N., Sniffen, C.J., Smith, R.D. and Kronfeld, D.S., 1985. Path analysis of dry period nutrition, postpartum metabolic and reproductive disorders, and mastitis in Holstein cows. J. Dairy Sci., 68: 2347-2360. Dijkhuizen, A.A., 1983. Economische aspecten van ziekten en ziektebestrijding bij melkvee. Proefschrift, Utrecht. Distl, O., 1985. Estimation of variance components for fertility parameters and covariance components between fertility and milk production parameters in cattle. 36th Annual Meeting of the E.A.A.P., 30 September-3 October 1985, at Kallithea, Halkidiki, Greece. Dohoo, I.R. and Martin, S.W., 1984. Disease, production and culling in Holstein--Friesian cows. III. Disease and production as determinants of disease. Prev. Vet. Med., 2: 671-690. Dtiring, F., 1987. Untersuchungen zur Gesundheitssituation in Schleswig-Holsteinischen Milchviehherden. Diss. agr., Kiel. Emanuelson, U., Danell, B. and Philipsson, J., 1987. Genetic parameters for clinical mastitis, somatic cell counts and milk production estimated by multiple trait REML. Swedisch University of Agricultural Sciences, Department of Animal Breeding and Genetics, Uppsala, Rep. No. 73. Erb, H.N., Smith, R.D., Oltenacu, P.A., Guard, C.L., Hillman, R.B., Powers, P.A., Smith, M.C. and White, M.E., 1985. Path model of reproductive disorders and performance, milk fever, mastitis, milk yield and culling in Holstein cows. J. Dairy Sci., 68: 3337-3349. Glibotic, A., 1986. Erhebung von tieriirztlichen Daten in einer Rinderpraxis - FruchtbarkeitsstSrungen und ihre Beziehungen zur Milchleistung. Diss. med. vet., Miinchen. GrShn, Y., Saloniemi, H. and Syv~ij~irvi,J., 1986. An epidemiological and genetic study on registered diseases in Finnish Ayrshire cattle. III. Metabolic diseases. Acta Vet. Scand., 27: 209222. Kauppinen, K., 1984. Annual milk yield and reproduction performance of ketotic and non-ketotic dairy cows. Zentralbl. Veterinaermed. Reihe, A, 31: 694-704. LindstrSm, U.B. and Syv~ij~irvi,J., 1978. Use of field records in breeding for mastitis resistance in dairy cattle. Livest. Prod. Sci., 5: 29-44. Martin, S.W., Aziz, S.A., Sandals, C.D. and Curtis, R.A., 1982. The association between clinical disease, production and culling of Holstein-Friesian cows. Can. J. Anim. Sci., 62: 633-640. Meijering, A. and Gianola, D., 1985. Linear versus nonlinear methods of sire evaluation for categorical traits: a simulation study. Genet. Sel. Evol., 17:115-132. Norman, H.D. and Van Vleck, L.D., 1972. Type appraisal: Relationships of first lactation production and type traits with lifetime performance. J. Dairy Sci., 55:1726-1734. Philipsson, J., Thafvelin, B. and Hedebro-Velander, I., 1980. Genetic studies on disease recording in first lactation cows of Swedish dairy breeds. Acta Agric. Scand., 30: 327-335. RSsch, H., 1984. Beziehungen zwischen Fruchtbarkeitsparametern und Milchleistungsparametern in der Fleckviehpopulation der Besamungsstation Meggle. Diss. med. vet., Miinchen. Shanks, R.D., Berger, P.J., Freeman, A.E. and Dickinson, F.N., 1982. Genetic and phenotypic relations of milk production and postpartum length with health and lactation curve traits by lactation. J. Dairy Sci., 65: 1612-1623. Solbu, H., 1983. Disease recording in Norwegian dairy cattle. I. Disease incidences and non-genetic effects on mastitis, ketosis and milk fever. Z. Tierz. Zuechtungsbiol., 100: 139-157. Solbu, H., 1984. Disease recording in Norwegian dairy cattle. III. Factors affecting diseases related to the reproductive performance. Z. Tierz. Zuechtungsbiol., 101: 210-219. Wilton, J.W., Van Vleck, L.D., Everett, R.W., Gutherie, R.S. and Roberts, S.J., 1972. Genetic and environmental aspects of udder infections. J. Dairy Sci., 55: 183-193.
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Wurm, A., 1985. Erhebung von tier~irztlichen Daten in einer Rinderpraxis-Stoffwechsel- und Eutererkrankungen sowie deren Beziehung zur Milchleistung. Diss. med. vet., Miinchen. KURZFASSUNG Distl, 0., Wurm, A., Glibotic, A., Brem, G. und Kriiut~lich, H., 1989. Analyse der Beziehungen zwischen tier~irztlich erhobenen Produktionskrankheiten und der Milchleistung bei Milchkiihen. Livest. Prod. Sci., 23:67-78 {auf englisch). Fiir die Untersuchung des Zusammenhangs zwischen dem Vorkommen von Stoffwechsel-, Euter- und Fruchtbarkeitserkrankungen und' der Milchleistung der Kuh sowie der Herde wurden tier~irztliche Diagnosen verwendet. Die Krankheitsh~iufigkeiten wurden in einer Tierarztpraxis von April 1982 bis M~irz 1983 erfat~t. Insgesamt standen 1686 Ktihe des Deutschen Fleckviehs (DFV) und 2178 Ktihe des Deutschen Braunviehs (DBV) ftir die statistische Auswertung mit einem Least Squares Modell zur Verftigung. Folgende Effekte wurden berticksichtigt: Rasse, Laktationsnummer, Kalbemonat, Herdeneffekte (Krankheitsh~iufigkeit, Milchleistung), Milchleistung der Kuh. Stoffwechselerkrankungen (Ketose, Milchfieber, alle Stoffwechselerkrankungen) zeigten zur 305-Tage-Milch-kg-Leistung der Kuh positive und signifikante Korrelationen filr das DBV (r: 0,07-0,12 ), w~ihrend beim DFV die Korrelationen nahe Null waren (r: 0,02-0,04). Ftir die Eutererkrankungen (akute und chronische Mastitis, Euter- und Zitzenverletzungen) konnten keine Beziehungen zur 305-Tage-Milch-kg-Leistung der Ktihe gefunden werden. Bei den Fruchtbarkeitserkrankungen (Nachgeburtsverhalten, Endometritis, AnSstrie, Ovarzysten) ergaben sich nur fiir die Ovarzysten bei beiden Rassen (DFV: r= 0,08; DBV: r = 0,13) signifikante Korrelationen zur 305-Tage-Milch-kg-Leistung der Kuh. Bei Ansteigen des Herdendurchschnitts in der 305-Tage-Milch-kg-Leistung konnte ein Abfallender Krankheitsfrequenzen ftir die Stoffwechselerkrankungen, Nachgeburtsverhalten, Ovarzysten und AnSstrie beobachtet werden. Daraus kann folgende Schlu£folgerung gezogen werden. Eine hohe Milchleistung bei der Milchkuh ftihrt im Vergleich zu einer niedrigen Milchleistung zu einem grSLeren Risiko, an einer Stoffwechselerkrankung oder an bestimmten Fruchtbarkeitsst5rungen zu erkranken. Jedoch kann durch gutes Management und der Leistung angepai~te Ftitterung in Herden mit hoher Milcheistung die Stoffwechselbelastung der Hochleistungsktihe soweit verringert werden, da£ die Krankheitsh~iufigkeit nicht mit dem Herdenniveau in der Milch-kg-Leistung zunimmt, sondern bei Stoffwechsel- und einigen Fruchtbarkeitserkrankungen abnimmt. RESUME Distl, O., Wurm, A., Glibotic, A., Brem, G. et Kriiu£1ich, H., 1989. Analyse des relations entre les maladies de production enregistr~es en pratique v~t6rinaire et la production laiti~re des vaches. Livest. Prod. Sci.R, 23:67-78 (en anglais). On a utilis~ les enregistrements effectu~s par les v~t~rinaires praticiens pour estimer les relations entre la fr~quence de diff~rentes maladies et la production laiti~re des vaches et des troupeaux. Les enregistrements sur 1686 vaches Simmental allemandes (DFV) et 2178 Brunes des Alpes allemandes (DBV) ont ~t~ analys~s par un module en moindres carr~s pour la race, le num~ro de lactation, le mois de v~lage, l'effet troupeau (fr~quence des maladies, production laiti~re) et le niveau de production de la vache. La fr~quence des maladies mgtaboliques (c~toses, fi~vre vitulaire, ensemble des maladies) a dt~ li~e positivement ~ la production laiti~re (en 305 jours) des vaches, les correlations Stant signifi-
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O. DISTLET AL.
catives pour les DBV (r=0,07 ~ 0,12) mais voisines de 0 pour les DFV (r=0,02 ~ 0,04). Pour les maladies de la mamelle (mammites aigues et chroniques, lSsions du pis) l'association avec la production en 305 jours a ~t~ voisine de z~ro. Parmi les troubles de la reproduction (r~tentions placentaires, mStrites, anoestrus, kystes ovariens) seule la fr~quence des kystes a St~ li~e significativement ~ la production laiti~re (en 305 jours) des vaches (r=0,08 pour les DFV et 0,13 pour les DBV. Quand la production du troupeau s'~l~ve, la frSquence des maladies m~taboliques et de la reproduction diminue. En conclusion, l'accroissement de la production laiti~re des vaches conduit ~ une augmentation de la frSquence de certaines maladies. Cependant cette derni~re est compens~e dans les troupeaux haute production par une alimentation et un mSnagement am$1ior~s.
67
Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
Analysis of Relationships between Veterinary Recorded Production Diseases and Milk Production in Dairy Cows 0. DISTL, A. WURM, A. GLIBOTIC, G. BREM and H. KRAU£LICH
Institut f~r Tierzucht und Tierhygiene der Universitiit Mi~nchen, Veteriniirstrafle 13, D-8000 Mi~nchen 22 (Federal Republic o[ Germany) (Accepted for publication 5 April 1989)
ABSTRACT Distl, 0., Wurm, A., Glibotic, A., Brem, G. and Kr~iuglich, H., 1989. Analysis of relationships between veterinary recorded production diseases and milk production in dairy cows. Livest. Prod. Sci., 23: 67-78. Veterinary diagnoses were used to estimate the relationships between various disease frequencies and milk production of the cow and the herd. For the analysis, diseases were registered in a veterinary practice. Records of a total of 1686 German Simmental (DFV) cows and 2178 German Brown Swiss (DBV) cows were used in a least squares model with the following effects: breed, lactation number, month of calving, herd effects (disease frequency, milk production), milk production of the cow. Metabolic disease frequencies (ketosis, milk fever, all metabolic diseases) were related positively to 305-day milk yield of the cow and were significant for DBV (r=0.07-0.12), but for DFV correlations were near zero (r=0.02-0.04). For udder diseases (acute and chronic mastitis, injuries of the udder), the associations with 305-day milk yield were near zero. In reproductive disorders (retained placenta, endometritis, anoestrus, ovarian cysts), only the frequency of ovarian cysts had a significant positive correlation with 305-day milk yield of the cows in both breeds (DFV: r=0.08; DBV: r=0.13). With increasing herd milk production, disease frequencies decreased for metabolic and reproductive disorders. It can be concluded that increasing milk yield of the cows leads to an increase in the frequencies of certain diseases. However, better feeding and management in high producing herds counterbalanced the negative effect of high milk production of cows on disease occurrence.
INTRODUCTION
Besides milk production, secondary traits like fertility and susceptibility to diseases alter the efficiency of dairy cattle production and affect the profit. High-yielding dairy cows could be more susceptible to production diseases in this way reducing the income from their milk. On the other hand, high yielding herds could decrease their disease frequencies by good management to a higher 0301-6226/89/$03.50
© 1989 Elsevier Science Publishers B.V.
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extent than low yielding herds. Therefore, cows yielding the same milk production, but kept in herds with different milk production levels, might not be comparable in their production disease frequencies. Discussing the associations between milk production and production disease frequencies, two components have to be taken into account, the individual component of the cow and the herd effect. The objective of our study is to analyse the relationships between the most frequent veterinary diagnosed and treated production diseases and milk production, based on the individual records of the cows and on the herd averages. MATERIAL AND METHODS
Diagnoses and treatments of cows were recorded in one veterinary practice. A detailed description of the recording of disease data is given elsewhere (Brem, 1982; Wurm, 1985; Glibotic, 1986). The recording period started in April 1982 and ended in March 1983. A survey on the frequency of some veterinary diagnoses and on the milk production data of the analysed material is given in Table 1. The milk recording statistics are in good agreement with figures of 305-day milk production of the region in which the veterinary practice is situated. Of all registered diagnoses, only the diagnoses of major importance were analysed. A cow was considered as diseased, if the disorder was diagnosed or treated at least once during the first 4 months after calving. This restriction might influence only these disease frequencies which are not related to the postpartum period. However, most metabolic, udder and fertility disorders occur within the first months after calving. TABLE 1 Distribution of veterinary diagnoses and average 305-day milk production of cows (n = 3864 ) and herds (n= 186) German Simmenml(DFV)
Brown Swiss(DBV)
Cows
Herds
Cows
Herds
n
1686
110
2178
111
Frequency (%) of Metabolic disorders Udder disorders Fertility disorders
4.6 4.8 16.1
5.2 4.8 15.7
5.0 7.8 13.5
4.7 7.2 13.7
Milk yield (kg) Fat content (%) Protein content (To)
4733 _+945 3.86 _+0.32 3.33 _+0.19
4273 _+559 3.85 _+0.17 3.32 _+0.10
5104-+_1070 3.85 _+0.32 3.31 _+0.19
4613 ___625 3.83 _+0.16 3.31 _+0.10
RELATIONSHIPS BETWEEN DISEASES AND MILK PRODUCTION
69
In the statistical analysis, only data from cows under milk recording are included. In some herds, cows of both breeds, German Simmental (DFV) and Brown Swiss (DBV), were kept and in this case herd averages were computed separately for each breed. The following disease frequencies, based on veterinary recordings, were analysed: Metabolic disorders: milk fever; ketosis; all metabolic diseases. Udder disorders: mastitis; acute mastitis; chronic mastitis; injuries of teats and udder. Fertility disorders: retained placenta; endometritis; anoestrus; ovarian cysts. All metabolic diseases comprise all veterinary diagnosed or treated metabolic diseases, e.g., milk fever, ketosis, hypomagnesaemia, osteomalacia, etc. Concerning the diagnosis of mastitis, all cases of acute and chronic mastitis are included. Under the diagnosis of endometritis the following uterus disorders are included: abnormal lochia; endometritis; metritis; pyometra. Anoestrus is used as a symptomatic diagnosis and may also be due to acyclia or persistent corpus luteum. Milk production parameters (305-day lactation and average milk production of the first three milk recordings after calving) were milk yield (kg), fat content (%), protein content (%) and maximum daily milk yield (kg). The following statistical model for the all-or-none disease parameters was employed: Yijk~mno=/~+Ai +By + Ck +b(HM-D~:i) + b(HM-Yml:i) +b(HM-Fm2:i) + b ( HM-Pm3:i ) + b ( CO- Ynl:i ) + b ( eO-Fn2:i ) + b ( CO-Pn3:~) + %ktmno where/~ = intercept; A~= fixed effect of breed i (i-- 1,2);Bj = fixed effect of lactation number j ( j = l - 7 ) ; Ch=fixed effect of calving month k ( k = l - 1 2 ) ; b= linear regression coefficient; HM-Dt:i= herdmate average for the disease frequency being analysed within breed i; H M - Yml:i = herdmate average for milk yield within breed i; HM-Fm2:i = herdmate average for fat content within breed i; HM-Pm3:i=herdmate average for protein content within breed i; COYnx:i = milk yield of the cow within breed i; CO-F~2:~= fat content of the cow's milk production within breed i; CO-Pn3:~=protein content of the cow's milk production within breed i; e~ih~o= random residual effect; Y~jkLm~o= not diSeased or diseased cow (0/1). The all-or-none parameters were analysed as quasi-continuous traits. Quadratic and cubic regression coefficients for herdmate averages and for cow milk production were meaningless and could therefore be neglected. Milk yield, fat and protein content could be regarded in the model simultaneously because there were no indications of a multicollinearity problem. From the statistical viewpoint, non-linear probability models might be more appropriate than the linear probability model employed, but simulation studies and application to
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field data showed that the benefits of the non-linear probability model are rather limited (Distl, 1985; Meijering and Gianola, 1985). RESULTS
The relative contribution (%) of important systematic influences on disease frequencies to the total explained variance by the applied model are shown in Table 2. The accounted variance of the whole model (R 2) varied between 2.3 and 18.2%, depending on the analyged disease frequency. The most important systematic influence was the herd effect. About 30-80% of the total explained variance was accounted for by the herdmate average of disease frequency. A seasonal pattern for the incidence of ketosis could be found. Ketosis occurred more frequently in the winter months than in the other months of the year. A significant influence of the calving m o n t h on mastitis was observed, but no clear seasonal pattern was evident. As expected, lactation number exerted a significant influence on the occurrence of milk fever. During the first three lactations, only very few cases of milk fever were diagnosed. The highest frequency of milk fever (9.5%) was found in the sixth lactation. Metabolic disorders were more frequent in DBV than in DFV, whereas udder and fertility disorders occurred more often in DFV than in DBV (Table 3 ), but the LS means for the breeds for all metabolic diseases showed significant difTABLE 2 Explained variance in percent (R 2) of some systematic influences on metabolic, udder and fertility disorders Disorder
Metabolic disorders Milk fever Ketosis All metabolic diseases Udder disorders Mastitis Acute mastitis Chronic mastitis Injuries of teats and udder
Month of calving
Lactation number
Disease frequency of herdmates
R2 (%)
25.9***
41.2"** 73.9*** 72.1"**
11.7 18.2 17.6
72.7*** 71.6"** 74.2*** 32.8***
12.6 10.4 9.4 2.3
78.8*** 66.8* ** 75.7*** 81.2"**
8.2 9.4 13.3 15.8
4.8* 11.4"**
6.9** 8.0**
Fertility disorders Retained placenta Endometritis Anoestrus Ovarian cysts *P< 0.05; **P< 0.01; ***P< 0.001.
RELATIONSHIPS BETWEEN DISEASES AND MILK PRODUCTION
71
TABLE 3 LS means a n d t h e i r s t a n d a r d errors for the breeds G e r m a n S i m m e n t a l ( D F V ) a n d Brown Swiss ( D B V ) in disease frequencies (%) Disorder
DFV
DBV
Metabolic disorders Milk fever Ketosis All metabolic diseases
3.02 ± 1.07 1.09 ± 0.69 3.26 +_ 1.24 a
4.43 ± 1.00 1.74 ± 0.75 6.42 ± 1.17 a
Udder disorders Mastitis Acute mastitis Chronic mastitis Injuries of teats a n d udder
6.92 ± 1.47 3.38 ± 1.15 4.07 _+ 1.13 0.10 _+0.33
6.19 ± 3.12 ± 3.70 ± 0.17 ±
1.39 1.08 1.06 0.31
4.08 ± 1.24 2.31 ± 1.01 3.39 _+1.04 11.71 ± 1.69
3.97 ± 1.74_ 3.00 ± 10.18 ±
1.17 0.94 0.98 1.58
Fertility disorders Retained placenta Endometritis Anoestrus Ovarian cysts
aDifference between breeds: P < 0.05.
ferences only between German Simmental (DFV) and Brown Swiss (DBV) cows. The risk of metabolic diseases for German Brown Swiss cows was nearly twice that of German Simmental cows. The associations between milk production and the occurrence of metabolic, udder as well as fertility disorders were estimated by correlation coefficients and are shown in Table 4. The correlation coefficients indicate that the risk of increasing disease frequency with a higher deviation of milk production from the herdmate average seems rather low. In German Simmental (DFV) cows, only chronic mastitis and ovarian cysts were related significantly to individual milk yield. For German Brown Swiss (DBV) cows, significant associations were found between 305-day milk yield and metabolic disorders, teat injuries and udder as well as ovarian cysts. Also for German Brown Swiss (DBV) cows, the correlations between protein content and metabolic disorders (milk fever, all metabolic disorders) as well as fertility disorders (endometritis, anoestrus, ovarian cysts) were significantly negative. Similar results revealed the correlation analysis between disease frequencies and the average milk production of the first three milk recordings after calving as well as the maximum daily milk yield (Wurm, 1985; Glibotic, 1986). When compared with the individual milk production of the cow, the herdmate average production in milk yield gave regression and correlation coefficients in which the signs were reversed for nearly all analysed diseases. The expected changes in disease frequencies per one standard deviation of 305-day
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o. DISTL ET AL
TABLE 4 Significant correlation coefficients between metabolic, udder, fertility disorders and milk production (305-day lactation) of German Simmental (DFV) and Brown Swiss cows (DBV) Disorder
Milk yield DFV
Metabolic disorders Milk fever Ketosis All metabolic Disorders Udder disorders Mastitis Acute mastitis Chronic mastitis Injuries of teats and udder Fertility disorders Retained placenta Endometritis Anoestrus Ovarian cysts
DBV
0.07* 0.09* 0.12"
Fat c o n t e n t
Protein content
DFV
DFV
DBV
- 0.08* - 0.07* -0.09*
DBV
- 0.08* -0.11"*
0.08* - 0.08*
- 0.07* 0.06* 0.08*
0.13"**
0.06* - 0.06* - 0.06* -0.09**
*P < 0.05; **P < 0.01; ***P < 0.001.
TABLE 5 Expected changes in disease frequencies (%) per one unit of standard deviation in 305-day lac tation milk yield for German Simmental (DFV) and Brown Swiss cows (DBV) Disorder
305-day milk yield DFV
Metabolic disorders Milk fever Ketosis All metabolic disorders Fertility disorders Retained placenta Endometritis Anoestrus Ovarian cysts
DBV Herd
0.73 0.57 1.16
- 1.44 - 0.60 - 1.80
1.01 1.67"* 2.63**
- 1.76" - 0.69 - 2.22*
0.29 1.28 0.89 3.28**
0.45 -0.19 - 0.56 - 1.26
0.93 -0.11 0.90 4.69***
- 1.14 0.34 - 0.76 - 2.61
* P < 0.05; * * P < 0.01; ***P < 0.001.
Cow
Herd
Cow
RELATIONSHIPS BETWEEN DISEASES AND MILK PRODUCTION
73
milk yield of the individual cow and the herd are given in Table 5 for DFV and DBV. The regression coefficients between udder diseases and milk yield were small and are therefore not displayed in the tables. The opposite influences of increasing herdmate milk yield and increasing individual cow milk yield were almost balanced for metabolic disorders, anoestrus and retained placenta. The frequency of ovarian cysts was affected more by the milk yield of the cow than by herdmate milk production. The expected changes with milk yield in the frequency of endometritis differed between the breeds DFV and DBV. DISCUSSION AND CONCLUSIONS
The analysis of systematic effects showed that the herd effect was the most important factor in the incidence of metabolic, udder and fertility disorders. In Norway (Solbu, 1983) and Sweden (Philipsson et al., 1980), the same results were found for ketosis, udder and fertility disorders. The frequency of milk fever increased significantly with parity. Age effects and milk fever occurring in preceding lactations may be predisposing factors for milk fever in later lactations. Culling because of milk fever could lead to a reduction in milk fever with increasing lactation number. The significant effect of month on ketosis can be an indication that nutrition problems play a role in the pathogenesis of ketosis. The explained variance in the analysis of the investigated disease frequencies is smaller in comparison to the analysis of milk production data. This may be due to a large individual influence of the cow on disease occurrence. Significant breed differences were found only for all metabolic diseases. A comparison of the two breeds, DFV and DBV, within herds was not possible. Therefore interactions between herds and breeds can influence the LS means of breeds. The phenotypic relationships between milk production of the cow and disease frequencies were rather low and positive. Nevertheless, the rather low correlations were, in some cases, significantly different from zero. The tendency could be noted that the associations between milk production of the cow and of the herd seemed to be more evident in the breed DBV than in DFV. Analysing the association between milk production and disease frequency, two different aspects can be considered. Diseases often reduce milk production (e.g., Dijkhuizen, 1983). To show the depression of milk yield by disease occurrence was not the objective of this study. On the contrary, it should be analysed if cows with high milk production are exposed to increasing risk of disease occurrence. The milk production parameters used should be appropriate for this purpose because milk recording is usually carried out only in healthy cows and the 100- or 305-day lactation records are estimated as in healthy cows. A slight underestimation of the correlation coefficients could be possible
74
O. DISTL ET AL.
if some of the diseased cows were milk recorded. Lactation milk production may also be reduced if diseases lead to permanent organ defects and following the depression of milk production. Using the previous lactation milk production instead of the current lactation has also some disadvantages: first lactating cows must be excluded; diseases might have affected the previous lactation milk production; the interaction between lactation number and milk production is neglected. Breed differences in the correlation analysis between milk production and disease frequencies can be partly caused by the higher average and variation in milk production of DBV in comparison to DFV. Crossbreeding of German Brown Swiss cows with U.S.-Brown Swiss bulls may also be of importance. Further reasons could be management factors because there was no complete overlapping of the different breeds within herds. In most studies, a slight positive phenotypic correlation between the current individual milk yield and ketosis (Norman and Van Vleck, 1972; Martin et al., 1982; Berglund and Larsson, 1983; Solbu, 1983; Kauppinen, 1984; Dfiring, 1987) as well as milk fever (Solbu, 1983; Diiring, 1987) was found. Norman and Van Vleck (1972) estimated positive phenotypic interrelationships between the frequency of ketosis and lifetime performance as well as first lactation milk yield. Analyses using previous milk yield indicated that cows with increasing previous milk yield are at higher risk of occurrence of milk fever (Dohoo and Martin, 1984; GrShn et al., 1986; Bendixen et al., 1987) and ketosis (Martin et al., 1982; Curtis et al., 1985; GrShn et al., 1986). However, Erb et al. (1985) and Curtis et al. (1985) could not confirm the positive associations between previous milk yield and milk fever; also Dohoo and Martin (1984) did not find a positive relationship between ketosis and previous milk yield. Considering the relationships between the frequencies of fertility disorders and current or previous milk yield, almost consistent estimates were reported for cystic ovaries, whereas for retained placenta, endometritis and metritis the estimates are rather inconsistent in the literature. Cows with high milk yield in previous or current lactation seem to be at increasing risk for ovarian cysts (Norman and Van Vleck, 1972; Martin et al., 1982; Shanks et al., 1982; Solbu, 1984; Coleman et al., 1985; Erb et al., 1985 ). Solbu (1984) also found a positive phenotypic correlation between current milk yield of the cow and anoestrus as well as metritis. In contrast to Solbu (1984), previous lactation milk yield was not a risk factor for metritis in the study of Erb et al. (1985) as well as in the analysis of Dohoo and Martin (1984). Retained placenta was associated with lower milk yield of the current lactation in Norwegian Red and White dairy cows (Solbu, 1984), whereas Diiring (1987) found in German Red and White as well as in German Black and White cows positive phenotypic correlations between retained placenta and current milk yield. Inflammations of the reproductive tract may influence current milk production. Therefore, the correlation estimates between milk yield in the same lactation and retained placenta
RELATIONSHIPS BETWEEN DISEASES AND MILK PRODUCTION
75
as well as metritis or endometritis could be biased downwards. The same bias may also influence the correlation between mastitis and milk yield. This may explain to some extent the large variations in phenotypic correlations between these two traits, as reported in literature ( N o r m a n and Van Vleck, 1972; Wilton et al., 1972; LindstrSm and Syv~ij~rvi, 1978; Solbu, 1983; Bunch et al., 1984; Dohoo and Martin, 1984; Erb et al., 1985; Diiring, 1987; Emanuelson et al., 1987). The studies of Dohoo and Martin (1984), Erb et al. (1985) and Emanuelson et al. (1987) indicate that previous milk yield and frequency of mastitis may not be related. These findings are in agreement with the analysis of our data set, in which monthly milk recordings of cows which were diseased at the day of milk recording were not included. In contrast to Solbu (1983) and GrShn et al. (1986), a reduction in the frequencies of metabolic and some fertility disorders was found with increasing herdmate milk yield. It is interesting to note that the relationships between average herdmate milk yield production and fertility parameters also flow in a positive direction (RSsch, 1984). Herd milk production seems to be a good indicator of overall management in our material. Good management prevents metabolic diseases to nearly the same extent as high milk yield predisposes to metabolic diseases. Similar findings are also given for anoestrus in both breeds, DFV and DBV, and retained placenta in DBV. The management influence on ovarian cysts could be shown, but the milk production of the cow seems to be a more important risk factor. Increasing the milk production of cows in the same herd without improving management practices was shown to be a risk factor for metabolic and some fertility disorders. Furthermore, the analysis of the data of the two dual-purpose breeds, German Simmental and Brown Swiss, suggested that the milk production of cows can be increased without the risk of altering profit by higher occurrences of metabolic, udder and some fertility disorders, if management and feeding practices are adjusted for high-yielding cows.
REFERENCES Bendixen, P.H., Vilson, B., Ekesbo, I. and Astrand, D.B., 1987. Disease frequencies in dairy cows in Sweden. III. Parturient paresis. Prev. Vet. Med., 5: 87-97. Berglund, G. and Larsson, K., 1983. Milk ketone-bodies and reproductive performance in post partum dairy cows.V. International Conference on Production Disease in Farm Animals, 1012 August 1983, at Uppsala, Sweden. Brem, G., 1982. Ein System zur Erfassung von Gesundheitsdaten in Milchviehbetrieben und ihre Verarbeitung mit Hilfe tier~irztlicher Praxiscomputer. XIIth World Congress on Diseases of Cattle, Amsterdam, Vol. 1, pp. 609-612. Bunch, K.J., Heneghan, D.J.S., Hibbit, K.G. and Rowlands, G.J., 1984. Genetic influences on clinical mastitis and its relationship with milk yield, season and stage of lactation. Livest. Prod. Sci., 11: 91-104.
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Coleman, D.A., Thayne, W.V. and Dailey, R.A., 1985. Factors affecting reproductive performance of dairy cattle. J. Dairy Sci., 68: 1793-1803. Curtis, C.R., Erb, H.N., Sniffen, C.J., Smith, R.D. and Kronfeld, D.S., 1985. Path analysis of dry period nutrition, postpartum metabolic and reproductive disorders, and mastitis in Holstein cows. J. Dairy Sci., 68: 2347-2360. Dijkhuizen, A.A., 1983. Economische aspecten van ziekten en ziektebestrijding bij melkvee. Proefschrift, Utrecht. Distl, O., 1985. Estimation of variance components for fertility parameters and covariance components between fertility and milk production parameters in cattle. 36th Annual Meeting of the E.A.A.P., 30 September-3 October 1985, at Kallithea, Halkidiki, Greece. Dohoo, I.R. and Martin, S.W., 1984. Disease, production and culling in Holstein--Friesian cows. III. Disease and production as determinants of disease. Prev. Vet. Med., 2: 671-690. Dtiring, F., 1987. Untersuchungen zur Gesundheitssituation in Schleswig-Holsteinischen Milchviehherden. Diss. agr., Kiel. Emanuelson, U., Danell, B. and Philipsson, J., 1987. Genetic parameters for clinical mastitis, somatic cell counts and milk production estimated by multiple trait REML. Swedisch University of Agricultural Sciences, Department of Animal Breeding and Genetics, Uppsala, Rep. No. 73. Erb, H.N., Smith, R.D., Oltenacu, P.A., Guard, C.L., Hillman, R.B., Powers, P.A., Smith, M.C. and White, M.E., 1985. Path model of reproductive disorders and performance, milk fever, mastitis, milk yield and culling in Holstein cows. J. Dairy Sci., 68: 3337-3349. Glibotic, A., 1986. Erhebung von tieriirztlichen Daten in einer Rinderpraxis - FruchtbarkeitsstSrungen und ihre Beziehungen zur Milchleistung. Diss. med. vet., Miinchen. GrShn, Y., Saloniemi, H. and Syv~ij~irvi,J., 1986. An epidemiological and genetic study on registered diseases in Finnish Ayrshire cattle. III. Metabolic diseases. Acta Vet. Scand., 27: 209222. Kauppinen, K., 1984. Annual milk yield and reproduction performance of ketotic and non-ketotic dairy cows. Zentralbl. Veterinaermed. Reihe, A, 31: 694-704. LindstrSm, U.B. and Syv~ij~irvi,J., 1978. Use of field records in breeding for mastitis resistance in dairy cattle. Livest. Prod. Sci., 5: 29-44. Martin, S.W., Aziz, S.A., Sandals, C.D. and Curtis, R.A., 1982. The association between clinical disease, production and culling of Holstein-Friesian cows. Can. J. Anim. Sci., 62: 633-640. Meijering, A. and Gianola, D., 1985. Linear versus nonlinear methods of sire evaluation for categorical traits: a simulation study. Genet. Sel. Evol., 17:115-132. Norman, H.D. and Van Vleck, L.D., 1972. Type appraisal: Relationships of first lactation production and type traits with lifetime performance. J. Dairy Sci., 55:1726-1734. Philipsson, J., Thafvelin, B. and Hedebro-Velander, I., 1980. Genetic studies on disease recording in first lactation cows of Swedish dairy breeds. Acta Agric. Scand., 30: 327-335. RSsch, H., 1984. Beziehungen zwischen Fruchtbarkeitsparametern und Milchleistungsparametern in der Fleckviehpopulation der Besamungsstation Meggle. Diss. med. vet., Miinchen. Shanks, R.D., Berger, P.J., Freeman, A.E. and Dickinson, F.N., 1982. Genetic and phenotypic relations of milk production and postpartum length with health and lactation curve traits by lactation. J. Dairy Sci., 65: 1612-1623. Solbu, H., 1983. Disease recording in Norwegian dairy cattle. I. Disease incidences and non-genetic effects on mastitis, ketosis and milk fever. Z. Tierz. Zuechtungsbiol., 100: 139-157. Solbu, H., 1984. Disease recording in Norwegian dairy cattle. III. Factors affecting diseases related to the reproductive performance. Z. Tierz. Zuechtungsbiol., 101: 210-219. Wilton, J.W., Van Vleck, L.D., Everett, R.W., Gutherie, R.S. and Roberts, S.J., 1972. Genetic and environmental aspects of udder infections. J. Dairy Sci., 55: 183-193.
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Wurm, A., 1985. Erhebung von tier~irztlichen Daten in einer Rinderpraxis-Stoffwechsel- und Eutererkrankungen sowie deren Beziehung zur Milchleistung. Diss. med. vet., Miinchen. KURZFASSUNG Distl, 0., Wurm, A., Glibotic, A., Brem, G. und Kriiut~lich, H., 1989. Analyse der Beziehungen zwischen tier~irztlich erhobenen Produktionskrankheiten und der Milchleistung bei Milchkiihen. Livest. Prod. Sci., 23:67-78 {auf englisch). Fiir die Untersuchung des Zusammenhangs zwischen dem Vorkommen von Stoffwechsel-, Euter- und Fruchtbarkeitserkrankungen und' der Milchleistung der Kuh sowie der Herde wurden tier~irztliche Diagnosen verwendet. Die Krankheitsh~iufigkeiten wurden in einer Tierarztpraxis von April 1982 bis M~irz 1983 erfat~t. Insgesamt standen 1686 Ktihe des Deutschen Fleckviehs (DFV) und 2178 Ktihe des Deutschen Braunviehs (DBV) ftir die statistische Auswertung mit einem Least Squares Modell zur Verftigung. Folgende Effekte wurden berticksichtigt: Rasse, Laktationsnummer, Kalbemonat, Herdeneffekte (Krankheitsh~iufigkeit, Milchleistung), Milchleistung der Kuh. Stoffwechselerkrankungen (Ketose, Milchfieber, alle Stoffwechselerkrankungen) zeigten zur 305-Tage-Milch-kg-Leistung der Kuh positive und signifikante Korrelationen filr das DBV (r: 0,07-0,12 ), w~ihrend beim DFV die Korrelationen nahe Null waren (r: 0,02-0,04). Ftir die Eutererkrankungen (akute und chronische Mastitis, Euter- und Zitzenverletzungen) konnten keine Beziehungen zur 305-Tage-Milch-kg-Leistung der Ktihe gefunden werden. Bei den Fruchtbarkeitserkrankungen (Nachgeburtsverhalten, Endometritis, AnSstrie, Ovarzysten) ergaben sich nur fiir die Ovarzysten bei beiden Rassen (DFV: r= 0,08; DBV: r = 0,13) signifikante Korrelationen zur 305-Tage-Milch-kg-Leistung der Kuh. Bei Ansteigen des Herdendurchschnitts in der 305-Tage-Milch-kg-Leistung konnte ein Abfallender Krankheitsfrequenzen ftir die Stoffwechselerkrankungen, Nachgeburtsverhalten, Ovarzysten und AnSstrie beobachtet werden. Daraus kann folgende Schlu£folgerung gezogen werden. Eine hohe Milchleistung bei der Milchkuh ftihrt im Vergleich zu einer niedrigen Milchleistung zu einem grSLeren Risiko, an einer Stoffwechselerkrankung oder an bestimmten Fruchtbarkeitsst5rungen zu erkranken. Jedoch kann durch gutes Management und der Leistung angepai~te Ftitterung in Herden mit hoher Milcheistung die Stoffwechselbelastung der Hochleistungsktihe soweit verringert werden, da£ die Krankheitsh~iufigkeit nicht mit dem Herdenniveau in der Milch-kg-Leistung zunimmt, sondern bei Stoffwechsel- und einigen Fruchtbarkeitserkrankungen abnimmt. RESUME Distl, O., Wurm, A., Glibotic, A., Brem, G. et Kriiu£1ich, H., 1989. Analyse des relations entre les maladies de production enregistr~es en pratique v~t6rinaire et la production laiti~re des vaches. Livest. Prod. Sci.R, 23:67-78 (en anglais). On a utilis~ les enregistrements effectu~s par les v~t~rinaires praticiens pour estimer les relations entre la fr~quence de diff~rentes maladies et la production laiti~re des vaches et des troupeaux. Les enregistrements sur 1686 vaches Simmental allemandes (DFV) et 2178 Brunes des Alpes allemandes (DBV) ont ~t~ analys~s par un module en moindres carr~s pour la race, le num~ro de lactation, le mois de v~lage, l'effet troupeau (fr~quence des maladies, production laiti~re) et le niveau de production de la vache. La fr~quence des maladies mgtaboliques (c~toses, fi~vre vitulaire, ensemble des maladies) a dt~ li~e positivement ~ la production laiti~re (en 305 jours) des vaches, les correlations Stant signifi-
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O. DISTLET AL.
catives pour les DBV (r=0,07 ~ 0,12) mais voisines de 0 pour les DFV (r=0,02 ~ 0,04). Pour les maladies de la mamelle (mammites aigues et chroniques, lSsions du pis) l'association avec la production en 305 jours a ~t~ voisine de z~ro. Parmi les troubles de la reproduction (r~tentions placentaires, mStrites, anoestrus, kystes ovariens) seule la fr~quence des kystes a St~ li~e significativement ~ la production laiti~re (en 305 jours) des vaches (r=0,08 pour les DFV et 0,13 pour les DBV. Quand la production du troupeau s'~l~ve, la frSquence des maladies m~taboliques et de la reproduction diminue. En conclusion, l'accroissement de la production laiti~re des vaches conduit ~ une augmentation de la frSquence de certaines maladies. Cependant cette derni~re est compens~e dans les troupeaux haute production par une alimentation et un mSnagement am$1ior~s.