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Effect of Forage-Concentrate Ratio in Complete Feeds Fed ad Libitum on Feed Intake Prepartum and the Occurrence of Abomasal Displacement in Dairy Cows1
Effect of Forage-Concentrate Ratio in Complete Feeds Fed ad kibitum on Feed Intake Prepartum and the Occurrence of Abomasal Displacement in Dairy CowsI C. E. COPPOCK,2 C. H. NOLLER, and S. A. WOLFE Department of Animal Sciences and C. J. CALLAHAN and J. S. BAKER
Department of Veterinary Clinics, Purdue University Lafayette, Indiana 47907 Abstract
F o r t y Holstein cows were assigned to four complete feeds o f : a) 75::25; b) 6 0 : 4 0 ; c) 4 5 : 5 5 ; and d) 30:70-~forage to concentrate ratios, 28 days before parturition, to examine the effect of ration energy level on the ad libitum consumption of energy in relation to requirements. During 25 days following parturition, 0, 2, 4, and 4 cases of left displacement of the abomasum occurred in the four ration groups, respectively. The mean daily dry matter intake 28 days p r e p a r t m n did not differ significantly ( P < . 0 5 ) among treatment groups with all cows in the analysis or with only the cows without displacements. Regression analyses of dry matter intake on the 28 days prior to calving revealed a significant depression in intake as parturition approached by cows in Treatments 2, 3, and 4 but not by cows in Treatment 1. Digestible energy consumed during the 28 days before calving averaged 155, 138, 159, and 173% of National Research Council's maintenance requirements for the four treatment groups, respectively. Introduction
Abomasal displacement is a disorder in which the abomasum becomes distended with fluid or gas or both with attendant migration to an abnormal position. Right abomasal displacement (19) is usually accompanied by torsion and occurs when the abomasum moves dorsally and to the right in the abdominal cavity. The more common form in the United States is left displacement (LDA) which occurs when the abomasum moves to the left and dorsally and comes to rest between the rumen and the left abdominal wall. This condition is of conReceived for publicatlo~ December 6, 1971. 1 Journal Paper 4612, Purdue University Agricultural Experiment Station. 2 Visiting Professor from Cornell University.
siderable economic importance because of an increasing incidence and its association with high producing dairy cows. Despite much recent interest and study, the basic causative factors responsible for the disorder remain obscure. According to Svendsen (19) the occurrence of LDA since 1948 has been associated with intensive dairy cattle management in several countries, but it has not been found in areas where cattle husbandry is extensive and feed supplies less abundant. The incidence of L D A in the United States is probably increasing as pointed out by Robertson (15) who reported that 3% of the cattle admitted to the large animal hospital of the University of Pennsylvania in 1960 had LDA compared to 30% of the cattle admitted ~n 1963. l i e further noted that similar trends existed at other institutions in North America. The economic severity of this disorder can be appreciated from the estimate of Robertson and Boucher (]6) that each case may cost the farmer from $90 to $152 in loss of milk and associated medical ex~penses. The incidence among 30 affected herds in Pennsylvania ranged from 2 to 12% of the milking cows during a 39 month interval (15). Left displacement of the abomasum has occurred more frequently in older cows, in the winter and spring months, and near parturition (15). Data from 156 affected cows (15) showed that 86% of the LDA's were diagnosed between 2 weeks before and 2 weeks following calving, with a large majority occurring within 10 days after calving. Whitlock (22) also noted that over 80% of 227 cows with right or left displacement were detected within 30 days following parturition. Consequently, there appears to be an association between the occurrence of L D A and parturition, although the occasional occurence in bulls and heifers rules out a direct causal relationship between parturition and LDA (9, 19). Effect of grain feeding, l i e a v y grain feeding prepartum has been implicated in the occurrence of abomasal displacement by several writers 783
784
COPPOCK
(13, 15, 18, 23). Based on experience with 200 cases, Neal (13) concluded that either high grain feeding in late pregnancy or high protein feeding or both might be related to a high incidence of displacement. A comparison of management in 30 herds with LDA's to closely adjacent herds with no LDA's showed few differences except that the affected herds were fed significantly more grain the month before calving and throughout the winter (15). Smith (18) recently reported the occurrence of 11 abomasal displacements in 46 cows fed a complete ration of 40% alfalfa hay-60% concentrate ad libitum beginning 4 weeks before calving. Eight of the displacements occurred within 2 weeks postpartum. Milk production did not appear to be a major determining factor. Svendsen (19) succeeded in producing right displacements of the abomasum (RDA) by injection of volatile fatty acids ( ¥ F A ) into the abomasum and insutllation of this organ with nitrogen. His work also showed that high concentrate feeding and the injection of 300 ml of a solution of V F A from cows fed high concentrate rations decreased the rate of abomasal contractions. Moreover, concentrate additions to a hay diet increased gas production in the abomasum. Thus, the work of Svendsen (19, 20) strongly indicates an inhibition of abomasal motility and an increase in abomasal gas production are important causative factors in the occurrence of displacement in cows fed high levels of concentrate near parturition. This is the first report from a larger study designed to determine the effect of energy level (forage: concentrate ratio) in complete feeds on the ability of dairy cows offered these feeds ad libitum to meet their energy requirements beginning 28 days prepartum and throughout the following lactation. A relationship between rations and the incidence of LDA was observed, and the conditions associated will be described in this paper. Procedure
F o r t y Holstein cows were placed in groups of four based upon lactation number and predicted calving date and were assigned to treatments at random at least 4 weeks before their predicted calving date. Sixteen cows were approaching first lactation, 16 second lactation, and 8 third lactation. Subsequent loss of cows and their replacements caused an unequal number of animals per treatment. The 4 treatments were 4 complete feeds composed of: a) 75% forage---25% concentrate; b) 60 f o r a g e - JOURNAL OF DAIRY SCIENCE ~rOL. 55, NO. 6
ET AL
40% concentrate; c) 45% forage---55% concentrate; and d) 30% forage---70% concentrate, all ratios on a dry basis. One advantage of complete feeds is that the ration consumed by all cows can be defined; i.e., the exact proportion of forage to concentrate and the level of minerals can be the same for all cows in a treatment group. This is in contrast to conventional systems of feeding in which forage and concentrate are offered separately and where free choice mineral supplements are available which permit the expression of individual preference so that cows within groups may differ greatly in the rations actually eaten. The forage portion of the rations was composed of equal dry matter from corn silage and alfalfa-bromegrass silage medium length of chop. The composition of the concentrate mixtures used to make the 4 complete feeds is shown in T a b l e 1. The composition of the concentrate mixtures was varied to provide a calculated 15.5% crude protein, 1.0% calcium, .5% phosphorus, and .5% supplemental trace mineralized salt in the dry matter of each complete feed. These rations provided protein, calcium, and phosphorus in excess of the National Research Council (NRC) (12) requirements for lactating dairy cows. The complete feeds were blended once daffy in a horizontal mixer wagon with load cells and were fed twice daily in amounts to provide 5 to 10% weighbacks. The forages and concentrates were sampled 3 times per week, dried at 60 C and composited on a 4 week basis for grinding and chemical analysis. Laboratory dry matter TABLE 1. Composition of the four concentrate mixtures, a Ration Ingredient
1
2
3
4
(%) Shelled corn (rolled-medium) 61.5 72.5 Soybean meal 30.2 21.8 Trace mineral b salt 1.8 1.1 Dicalcium phosphate 2.8 1.7 Limestone 3.4 2.6 Vitamin premix c .4 .25 100.0 100.0
77.9 17.5 .8 1.2 2.4 .18 100.0
80.9 15.3 .6 .9 2.2 .15 100.0
a Air-dry basis. b Guaranteed to contain not less than, .50% Zn, .40% Mn, .25% Fe, .05% Cu, .01% I : and .01% Co. e Contained 2,250,000 I U vitamin A per kilogram and 440,000 IU vitamin D per kilogram.
FORAGE-CONCENTRATE
785
RATIO
was obtained at 100 C, and all intake data were calculated with this value. Acid detergent fiber, neutral detergent fiber, and lignin were analyzed according to Van Soest (21) pro: eedures; mineral element concentrations were obtained by emission spectrograph• The proximate and mineral composition of forages and concentrates are shown in Table 2• Cows were housed in a conventional stanchion barn with separate mangers and individual water cups. No feed was fed in the milking parlor, and no free choice mineral supplements were provided at any time. Daily individual feed intakes were recorded throughout. Exercise was provided by movement twice daily to a milking parlor• Body weights were taken once per week. Complete health records were maintained on each cow. The time interval from the beginning of the study until the last cow calved was 22 weeks• I n correcting the displaced abomasi, the right flank omentopexy method was used in all but two cases• I n Cow 382 the ventral abomasopexy was performed and in Cow 307 the left flank abomasopexy technique was employed.
~0
Results and Discussion
~ ~
: :
: :
: :
: :
~
:
:
:
:
A n increase in the occurrence of abomasal displacement with an increasing proportion of concentrate in the ration is apparent from these data (Table 3). The number of LDA in each treatment group (forage : concentrate ratio) was 0, 2, 4, and 4. The greater incidence of L D A as higher proportions of concentrate were fed agrees with results published previously by Neal (13), Robertson (15), and Smith (18). However, the possibility that high protein feeding might increase the incidence of displacement (13) cannot be determined from this study because protein levels were nearly identical in the 4 rations used. Similarly, amounts of calcium and phosphorus were nearly the same in the four rations.
~
TABLE 3. F o r a g e : concentrate ratios and the occurrence of left abomasal displacement, a Rations (Treatments) o9
o9
o9
Forage Concentrate Cows with LDA Total cows calving
1
2
3
4
75.2 24.8 0 10
60.2 39•8 2 12
45.2 54.8 4 10
30.3 69.7 4 11
Ratios expressed on a dry basis; forage dry matter was composed of equal parts of corn silage and alfalfa-grass silage• JOUR~AL O1~ DAIRY SCIENCE VOL. 55, NO. 6
786
COPPOCK ET AL
Robertson (15) reported that herds in which lead feeding and higher grain feeding postpartum were practiced had a significantly greater incidence of LDA than closely adjacent herds where lead feeding was not used and less grain was fed postpartum. Lead feeding is defined as the custom of increasing the amount of grain fed during 2 to 3 weeks prior to the predicted calving date to 1 to 1.5% of body weight. I n contrast, the differences between treatments in this study did not involve increasing amounts of grain as parturition approached but a constant ratio of forage to grain in complete rations offered ad libitum. However, it is impossible to separate effects of high grain feeding prepartum with higher grain feeding postpartum in this study as well as in others (13, 15, 18). I n this work and in the California report (18) the same complete feeds were fed both postpartum and prepartum. None of the cows in the study had a record of previous displacement. Because the earliest displacements occurred 3 days postpartum, it was believed that feeding prepartum or at parturition played a role in displacement. Therefore, mean dry matter intake for the 28 days prior to calving was analyzed. A treatment group by displacement factorial analysis of variance was used to test differences in dry matter intake/100 kg of body weight (Table 4). Group 1 was excluded because no cows in this group had LDA. No significant differences were detected between the three high grain rations, between the displacement groups, or the interaction (Table 4). The prepartum dry matter intake for cows without LDA versus those that developed L D A after calving ap-
Treatment
2~0 ~.., " ~ ' . . . . ~,
I - -
"~ = 1.55 - . O 0 4 1 X
2 ---
~" = 1.25 - . 0 0 8 5 X
3 --'--
~ = 1.20- .OZ41X
2.0
4 ....... Y = = 1,22- .0260X
1.8
~c* I.B
1.6
L6
1.4
1.4
1.2
1.2
Days
to Parturition
FIG. 1. Effect of treatment (forage: concentrate ratio) on the regression of dry matter intake 28 days prior to parturition. proached significance ( P ~ . 0 8 ) . To test the differences between treatments using all 4 groups, a one-way analysis of variance was run. No significant differences in the means of 1.62, 1.36, 1.51, and 1.58 kg DM/100 kg body weight were detected in an analysis including all cows, nor in an analysis with only the nonLDA cows. Although the means over 28 days do not show statistically significant differences, an analysis of the daily intake of each group reveals varying eating patterns. I n Figure 1, the regressions of DM intake on the 28 days prior to parturition are shown for the four treatments. There was a marked decrease in DM consumption by cows on Treatments 2, 3, and 4 as parturition approached. The regression coefficients differ ( P < . 0 1 ) from each other and all except Treatment i differ ( P < . 0 1 )
TABLE 4. Effect of forage: concentrate ratio and dry matter intake prior to parturition on left abomasal displacement following parturition. Treatment a 2 Cows without LDA Cows with LDA Main effects
1.45 (10) b .92 (2) 1.29 (12)
3
4
Main effects
(kg DM/100 kg body weight) 1.55 (6) 1.65 (7) 1.45 (4) 1.46 (4) 1.52 (10) 1.59 (11)
1.55 (23) 1.28 (10)
Analysis of variance Source Treatment main effects LDA versus no LDA main effects Interaction Error
df
lV[.S.
F Ratio
2 1 2 27
.2663 .4734 .0944 .1256
2.12 3.77 .75
a There were no abomasa] displacements in Treatment 1. b Number in parenthesis is the number of observations represented in each mean. JOURNAL OF DAIRY ~OIENCE ~OL. 55, NO. 6
TABLE 5. Characteristics of cows with left abomasal displacements.
Days from
Cow 184 382 197 276 278 307 254 (died) 356 (died) 242 171
5~
.¢ ¢5
Treatment group
Lactation
Body wt a
Days cartied calf Size
Calf % Of dam's wt
Sex
calving Type of to L D A surgical diagnosis fixation c
4 3 3 4 4 3 3 2 4 2
3 2 3 1 1 2 1 2 2 3
(kg) 691.7 603.3 680.4 498.0 459.5 675.8 648.6 585.1 607.8 762.0
282 289 285 277 279 276 267 280 275 287
(kg) 54.9 54.4 50.3 39.0 46.3 51.7 40.8 49.9 44.0 54.4
7.9 9.0 7.4 7.8 10.1 7.7 6.3 8.5 7.2 7.1
F M ~V[ F iV[ M F M F ~
12 9 7 16 3 17 25 9 3 5
621.2
+279.7
48.6
7.9
a Taken immediately following calving. b RP, retained placenta; OF, off feed; Me, metritis; Ma, mastitis; Dys, dystocia. c OM, omentopexy; YA, ventral abomasopexy; LA~ left flank abomasopexy.
10.6
OM VA OM OM OM LA OM OM OM OM
Disorders b Concurrent
Previous
Me Me Me Me ]Vie, Ma
RP, O F
Me
Ma, R P Me, R P
Ma, Dys, Me RP, Ma, Me
RP
m ©
788
COPPOCK ET AL
from zero. On the day prior to parturition the average dry matter consumption of the cows in Treatment 1 was approximately 25% greater than the average dry matter consumption of the other three treatment groups. High grain feeding prepartum appears to depress total dry matter intake at parturition. Lower dry matter consumption of the more digestible rations may have resulted in less rumen fill and greater opportunity for migration of the abomasum. Johnson et al. (7) observed a decrease in voluntary intake of forage dry matter of .2 k g / d a y each week of the dry period when cows were fed 2.7 kg of concentrate per day. Additional data on the cows in which displacement of the abomasum occurred are shown in Table 5. All displacements were to the left and were diagnosed between 3 and 25 days postpartum. The average gestation length was 279.7 days, which is nearly identical to the value used for Holsteins of 280 days by the National Dairy H e r d Improvement Cooperative. Calf weights appear to reflect the lactation number of the dam. The data show that 9 of the 10 cows had concurrent problems and 4 of the 10 had had other disorders since calving. Nine of the 10 cows with L D A had metritis and 5 had retained placenta compared to 6 eases of metritis and 8 retained placentas among the 33 cows with no abomasal displacement. F r o m a study of health records of 202 cows which had had LDA, Robertson (15) found that 15% had a previous disorder and 23% had a concurrent disease. Cow 254 died on the second post-operative day of a coliform and streptococcal septicemia. Cow 356 died on the second post-operative day of a vegetative endoearditis, metritis, and abomasal ulcers. Some association between amount of concentrate in the ration, parturition, and the occurrence of displacement seems apparent from the data in this study. The average days from calving to L D A diagnosis was 10.6, which agrees with previous writers (13, 22) who found the highest incidence within 30 days post-calving. However, in other reports (5, 8) peak concentrate intakes have not been attained until weeks 8 to 12 after calving, even though both concentrate and forage were fed nearly ad libitum. Thus, the interval characterized by the greatest occurence of displacements does not coincide with the interval of greatest concentrate intake. Nevertheless, these results lend credence to the conclusions of Svendsen (19, 20) that high concentrate diets fed near parturition provide conditions conducive to the occurrence of abomasal displacement. JOURNAL OF DAIRY SCIENCE VOL. 55, NO. 6
The practice of lead feeding became popular about 10 years ago following the recognition that many cows had the ability to produce at much higher levels if additional energy were provided in the form of grain during the first p a r t of lactation (6). I t seemed reasonable to use lead feeding prepartum to facilitate adjustment to higher grain feeding postpartum, and this approach has been recommended by several writers (1, 14, 17). However, at that time the assumed advantage of conditioning cows before calving was not tested a p a r t from high grain feeding following calving. Recently, Emery et al. (2) and Gardner (4) presented evidence which showed no benefit from lead feeding if cows were fed well following calving and were in good condition in late pregnancy. Recent energy metabolism studies at Beltsville (3) showed that the energy requirement for the last 2 to 3 months of gestation is no more than 10 to 20% of the cow's maintenance requirement instead of the 60 to 70% suggested by Morrison (11) and 30% by NRC (12). A comparison of the energy consumed using values from the recent NRC (12) publication to estimate the digestible energy (DE) content of the feeds fed in this study and to estimate the DE required for maintenance shows that the average DE consumed was 155, 138, 159, and 173% of that required for maintenance for the four groups during the 28 days preceding parturition. Consequently, the requirements for maintenance plus pregnancy can easily be met by rations high in good quality forage. Although many high producing dairy cows must rely on body energy reserves in early lactation to support milk production and these reserves should be replenished before the next parturition, the metabolism trials of Moe et al. (10) show that the energetic efficiency of fat deposition while the cow is lactating is about 82% compared to 59% while the cow is dry. Therefore, it would a p p e a r to be more efficient energetically to replenish lipid reserves in late lactation than in the dry period. While some dry period is probably necessary for most cows, it is neither necessary nor energetically efficient to use the dry period as a time for replenishment of nutrient reserves. I t is possible that the body condition of the cow in late pregnancy may govern the type of production response to lead feeding. The energy consumed by a dry pregnant cow in excess of the maintenance requirement can only be deposited as fat. The enzymes in body tissues that function in fat deposition are not the same as those which serve to mobilize fat
FORAGE-CONCENTRATE
for the secretion of milk in early lactation when energy requirements usually exceed the ability of the cow to eat feed. I n effect, feeding grain at high levels before calving may increase the stress on the cow at p a r t u r i t i o n when body metabolism must change direction f r o m fat deposition to fat mobilization, as well as provide a rumen fermentation medium which is conducive to a high occurrence of abomasal displacement. The conditions predisposing a cow to L D A seem to be enhanced by the feeding of a high p r o p o r t i o n of concentrate p r i o r and immediately following calving. W h e t h e r a constant ratio of f o r a g e to concentrate is used as in this study or an increasing p r o p o r t i o n as in lead feeding, abomasal disorders occur most often on the high grain diets. The theory of lead feeding seems to have evolved as an extension of the high production response obtained with higher concentrate feeding postpartum. Although it now seems necessary to feed high concentrate to high producing cows postpartum, there seems little reason to continue the practice of lead feeding p r e p a r t u m if cows are in good condition at drying off. E x p e r i mental data now available indicate lead feeding may be a contributing factor to the occurence of abomasal displacement.
Acknowledgments The authors wish to express their appreciation to Mrs. Theresa Frazer for help with many details associated with the collection and editing of the data in this study.
References (1) Cason, J. L., R. F. Davis, R. W. Hemken, J. H. Vandersall, and C. D. Caskey. 1965. Economical grain feeding for dairy cows. Univ. Maryland Ext. Bull., 202. (2) Emery, R. S., H. D. Hafs, D. Armstrong, and W. W. Snyder. 1969. Prepartum grain feeding effects on milk production, mammary edema, and incidence of diseases. J. Dairy Sci., 52: 345. (3) Flatt, W. P., P. W. Moe, and L. A. Moore. 1969. Influence of pregnancy and ration composition on energy utilization by dairy cows. European Ass. Animal Prod., Publ. ]2, p. 123. Orrel Press Ltd. (4) Gardner, R. W. 1969. Interactions of energy levels offered to Holstein cows prepartum and postpartum. 2. Production responses and blood composition changes. J. Dairy Sci., 52: 1973. (5) Hemken, R. W., and J. H. Vandersail. 1965. Intake levels during early lactation of the dairy cow. Prec. Maryland Nutrition Conf., p. 69. (6) Huffman, C. F. 1961. High-level grain feeding for dairy cows. J. Dairy Sci., 44 : 2113.
RATIO
789
(7) Johnson, W. L., G. W. Trimberger, M. J. Wright, L. D. Van Vleck, and C. R. Henderson. 1966. Voluntary intake of forage by Holstein cows as influenced by lactation, gestation, body weight and frequency of feeding. J. Dairy Sci., 49:856. (8) Jumah, H. F., B. R. Poulton, and W. P. Apgar. 1965. Energy and protein utilization during lactation. J. Dairy Sci., 48: 1210. (9) Mather, M. ~., and R. S. Dedrlek. 1966. Displacement of the abomasum. Cornell Vet., 56: 323. (10) Moe, P. W., H. F. Tyrrel], and W. P. Flatt. 1971. Energetics of body tissue mobilization. J. Dairy Sei., 54: 548. (11) Morrison, F. B. 1956. Feeds and Feeding. 22nd Edition. The Morrison Publishing Co., Ithaca, Mew York. (12) National Academy of Sciences--National Research Council. 1971. Nutrient requirements of domestic animals. Nutrient requirements of dairy cattle. No. 3. Washington, D.C. (13) Neal, P. A. 1964. Some critical observations on the etiology of displacement of the abomasum in the dairy cow. Nor& Vet.Med., 16: 361. (14) Reid, 5. T. 1961. Problems of feed evaluation related to feeding of dairy cows. J. Dairy Sci., 44: 2122. (15) Robertson, J. McD. 1968. Left displacement of the bovine abomasum: eplzootiologic factors. Amer. J. Vet. Res., 29: 421. (16) Robertson, J. M., and W. B. Boucher. 1966. Treatment of left displacement of the bovine abomasum. J. Amer. Vet. Med. Ass., 149: 1423. (17) Slack, S. T., J. ]~. Stone, and W. G. Merrill. 1965. Feeding the dairy cow for maximum returns. Cornell Ext. Ball., 1156. (18) Smith, N. E. 1971. Feed efficiency in intensive milk production. U. Calif. 10th Ann. Dairy Cattle Day Rep., p. 40. (19) Svendsen, Per. 1969. Etiology and pathogenesis of abomasal displacement in cattle. Nord. ¥et.-Med., 21: Supplement I. (20) Svendsen, Per. 1970. Abomasal displacement in cattle. The concentrations of volatile fatty acids in ruminal and abomasal contents and their influence on abomasal motility and the flow-rate of the abomasal contents. Nord. Vet.-Med., 22: 571. (21) Van Soest, P. J. 1967. Development of a comprehensive system of feed analyses and its application to forages. J. Animal Sci., 26 : 119. (22) Whitlock, R. H. 1969. Diseases of the abomasum associated with current feeding practices. J. Amer. Vet. Med. Ass., 154: 1203. (23) Woelffer, E. A. ]962. Stomachs out of order and out of place. Hoard's Dairyman, 107 : 1262. JOURNAL OF DAIRY SCIENCE VOL. 55, NO. 6
Department of Veterinary Clinics, Purdue University Lafayette, Indiana 47907 Abstract
F o r t y Holstein cows were assigned to four complete feeds o f : a) 75::25; b) 6 0 : 4 0 ; c) 4 5 : 5 5 ; and d) 30:70-~forage to concentrate ratios, 28 days before parturition, to examine the effect of ration energy level on the ad libitum consumption of energy in relation to requirements. During 25 days following parturition, 0, 2, 4, and 4 cases of left displacement of the abomasum occurred in the four ration groups, respectively. The mean daily dry matter intake 28 days p r e p a r t m n did not differ significantly ( P < . 0 5 ) among treatment groups with all cows in the analysis or with only the cows without displacements. Regression analyses of dry matter intake on the 28 days prior to calving revealed a significant depression in intake as parturition approached by cows in Treatments 2, 3, and 4 but not by cows in Treatment 1. Digestible energy consumed during the 28 days before calving averaged 155, 138, 159, and 173% of National Research Council's maintenance requirements for the four treatment groups, respectively. Introduction
Abomasal displacement is a disorder in which the abomasum becomes distended with fluid or gas or both with attendant migration to an abnormal position. Right abomasal displacement (19) is usually accompanied by torsion and occurs when the abomasum moves dorsally and to the right in the abdominal cavity. The more common form in the United States is left displacement (LDA) which occurs when the abomasum moves to the left and dorsally and comes to rest between the rumen and the left abdominal wall. This condition is of conReceived for publicatlo~ December 6, 1971. 1 Journal Paper 4612, Purdue University Agricultural Experiment Station. 2 Visiting Professor from Cornell University.
siderable economic importance because of an increasing incidence and its association with high producing dairy cows. Despite much recent interest and study, the basic causative factors responsible for the disorder remain obscure. According to Svendsen (19) the occurrence of LDA since 1948 has been associated with intensive dairy cattle management in several countries, but it has not been found in areas where cattle husbandry is extensive and feed supplies less abundant. The incidence of L D A in the United States is probably increasing as pointed out by Robertson (15) who reported that 3% of the cattle admitted to the large animal hospital of the University of Pennsylvania in 1960 had LDA compared to 30% of the cattle admitted ~n 1963. l i e further noted that similar trends existed at other institutions in North America. The economic severity of this disorder can be appreciated from the estimate of Robertson and Boucher (]6) that each case may cost the farmer from $90 to $152 in loss of milk and associated medical ex~penses. The incidence among 30 affected herds in Pennsylvania ranged from 2 to 12% of the milking cows during a 39 month interval (15). Left displacement of the abomasum has occurred more frequently in older cows, in the winter and spring months, and near parturition (15). Data from 156 affected cows (15) showed that 86% of the LDA's were diagnosed between 2 weeks before and 2 weeks following calving, with a large majority occurring within 10 days after calving. Whitlock (22) also noted that over 80% of 227 cows with right or left displacement were detected within 30 days following parturition. Consequently, there appears to be an association between the occurrence of L D A and parturition, although the occasional occurence in bulls and heifers rules out a direct causal relationship between parturition and LDA (9, 19). Effect of grain feeding, l i e a v y grain feeding prepartum has been implicated in the occurrence of abomasal displacement by several writers 783
784
COPPOCK
(13, 15, 18, 23). Based on experience with 200 cases, Neal (13) concluded that either high grain feeding in late pregnancy or high protein feeding or both might be related to a high incidence of displacement. A comparison of management in 30 herds with LDA's to closely adjacent herds with no LDA's showed few differences except that the affected herds were fed significantly more grain the month before calving and throughout the winter (15). Smith (18) recently reported the occurrence of 11 abomasal displacements in 46 cows fed a complete ration of 40% alfalfa hay-60% concentrate ad libitum beginning 4 weeks before calving. Eight of the displacements occurred within 2 weeks postpartum. Milk production did not appear to be a major determining factor. Svendsen (19) succeeded in producing right displacements of the abomasum (RDA) by injection of volatile fatty acids ( ¥ F A ) into the abomasum and insutllation of this organ with nitrogen. His work also showed that high concentrate feeding and the injection of 300 ml of a solution of V F A from cows fed high concentrate rations decreased the rate of abomasal contractions. Moreover, concentrate additions to a hay diet increased gas production in the abomasum. Thus, the work of Svendsen (19, 20) strongly indicates an inhibition of abomasal motility and an increase in abomasal gas production are important causative factors in the occurrence of displacement in cows fed high levels of concentrate near parturition. This is the first report from a larger study designed to determine the effect of energy level (forage: concentrate ratio) in complete feeds on the ability of dairy cows offered these feeds ad libitum to meet their energy requirements beginning 28 days prepartum and throughout the following lactation. A relationship between rations and the incidence of LDA was observed, and the conditions associated will be described in this paper. Procedure
F o r t y Holstein cows were placed in groups of four based upon lactation number and predicted calving date and were assigned to treatments at random at least 4 weeks before their predicted calving date. Sixteen cows were approaching first lactation, 16 second lactation, and 8 third lactation. Subsequent loss of cows and their replacements caused an unequal number of animals per treatment. The 4 treatments were 4 complete feeds composed of: a) 75% forage---25% concentrate; b) 60 f o r a g e - JOURNAL OF DAIRY SCIENCE ~rOL. 55, NO. 6
ET AL
40% concentrate; c) 45% forage---55% concentrate; and d) 30% forage---70% concentrate, all ratios on a dry basis. One advantage of complete feeds is that the ration consumed by all cows can be defined; i.e., the exact proportion of forage to concentrate and the level of minerals can be the same for all cows in a treatment group. This is in contrast to conventional systems of feeding in which forage and concentrate are offered separately and where free choice mineral supplements are available which permit the expression of individual preference so that cows within groups may differ greatly in the rations actually eaten. The forage portion of the rations was composed of equal dry matter from corn silage and alfalfa-bromegrass silage medium length of chop. The composition of the concentrate mixtures used to make the 4 complete feeds is shown in T a b l e 1. The composition of the concentrate mixtures was varied to provide a calculated 15.5% crude protein, 1.0% calcium, .5% phosphorus, and .5% supplemental trace mineralized salt in the dry matter of each complete feed. These rations provided protein, calcium, and phosphorus in excess of the National Research Council (NRC) (12) requirements for lactating dairy cows. The complete feeds were blended once daffy in a horizontal mixer wagon with load cells and were fed twice daily in amounts to provide 5 to 10% weighbacks. The forages and concentrates were sampled 3 times per week, dried at 60 C and composited on a 4 week basis for grinding and chemical analysis. Laboratory dry matter TABLE 1. Composition of the four concentrate mixtures, a Ration Ingredient
1
2
3
4
(%) Shelled corn (rolled-medium) 61.5 72.5 Soybean meal 30.2 21.8 Trace mineral b salt 1.8 1.1 Dicalcium phosphate 2.8 1.7 Limestone 3.4 2.6 Vitamin premix c .4 .25 100.0 100.0
77.9 17.5 .8 1.2 2.4 .18 100.0
80.9 15.3 .6 .9 2.2 .15 100.0
a Air-dry basis. b Guaranteed to contain not less than, .50% Zn, .40% Mn, .25% Fe, .05% Cu, .01% I : and .01% Co. e Contained 2,250,000 I U vitamin A per kilogram and 440,000 IU vitamin D per kilogram.
FORAGE-CONCENTRATE
785
RATIO
was obtained at 100 C, and all intake data were calculated with this value. Acid detergent fiber, neutral detergent fiber, and lignin were analyzed according to Van Soest (21) pro: eedures; mineral element concentrations were obtained by emission spectrograph• The proximate and mineral composition of forages and concentrates are shown in Table 2• Cows were housed in a conventional stanchion barn with separate mangers and individual water cups. No feed was fed in the milking parlor, and no free choice mineral supplements were provided at any time. Daily individual feed intakes were recorded throughout. Exercise was provided by movement twice daily to a milking parlor• Body weights were taken once per week. Complete health records were maintained on each cow. The time interval from the beginning of the study until the last cow calved was 22 weeks• I n correcting the displaced abomasi, the right flank omentopexy method was used in all but two cases• I n Cow 382 the ventral abomasopexy was performed and in Cow 307 the left flank abomasopexy technique was employed.
~0
Results and Discussion
~ ~
: :
: :
: :
: :
~
:
:
:
:
A n increase in the occurrence of abomasal displacement with an increasing proportion of concentrate in the ration is apparent from these data (Table 3). The number of LDA in each treatment group (forage : concentrate ratio) was 0, 2, 4, and 4. The greater incidence of L D A as higher proportions of concentrate were fed agrees with results published previously by Neal (13), Robertson (15), and Smith (18). However, the possibility that high protein feeding might increase the incidence of displacement (13) cannot be determined from this study because protein levels were nearly identical in the 4 rations used. Similarly, amounts of calcium and phosphorus were nearly the same in the four rations.
~
TABLE 3. F o r a g e : concentrate ratios and the occurrence of left abomasal displacement, a Rations (Treatments) o9
o9
o9
Forage Concentrate Cows with LDA Total cows calving
1
2
3
4
75.2 24.8 0 10
60.2 39•8 2 12
45.2 54.8 4 10
30.3 69.7 4 11
Ratios expressed on a dry basis; forage dry matter was composed of equal parts of corn silage and alfalfa-grass silage• JOUR~AL O1~ DAIRY SCIENCE VOL. 55, NO. 6
786
COPPOCK ET AL
Robertson (15) reported that herds in which lead feeding and higher grain feeding postpartum were practiced had a significantly greater incidence of LDA than closely adjacent herds where lead feeding was not used and less grain was fed postpartum. Lead feeding is defined as the custom of increasing the amount of grain fed during 2 to 3 weeks prior to the predicted calving date to 1 to 1.5% of body weight. I n contrast, the differences between treatments in this study did not involve increasing amounts of grain as parturition approached but a constant ratio of forage to grain in complete rations offered ad libitum. However, it is impossible to separate effects of high grain feeding prepartum with higher grain feeding postpartum in this study as well as in others (13, 15, 18). I n this work and in the California report (18) the same complete feeds were fed both postpartum and prepartum. None of the cows in the study had a record of previous displacement. Because the earliest displacements occurred 3 days postpartum, it was believed that feeding prepartum or at parturition played a role in displacement. Therefore, mean dry matter intake for the 28 days prior to calving was analyzed. A treatment group by displacement factorial analysis of variance was used to test differences in dry matter intake/100 kg of body weight (Table 4). Group 1 was excluded because no cows in this group had LDA. No significant differences were detected between the three high grain rations, between the displacement groups, or the interaction (Table 4). The prepartum dry matter intake for cows without LDA versus those that developed L D A after calving ap-
Treatment
2~0 ~.., " ~ ' . . . . ~,
I - -
"~ = 1.55 - . O 0 4 1 X
2 ---
~" = 1.25 - . 0 0 8 5 X
3 --'--
~ = 1.20- .OZ41X
2.0
4 ....... Y = = 1,22- .0260X
1.8
~c* I.B
1.6
L6
1.4
1.4
1.2
1.2
Days
to Parturition
FIG. 1. Effect of treatment (forage: concentrate ratio) on the regression of dry matter intake 28 days prior to parturition. proached significance ( P ~ . 0 8 ) . To test the differences between treatments using all 4 groups, a one-way analysis of variance was run. No significant differences in the means of 1.62, 1.36, 1.51, and 1.58 kg DM/100 kg body weight were detected in an analysis including all cows, nor in an analysis with only the nonLDA cows. Although the means over 28 days do not show statistically significant differences, an analysis of the daily intake of each group reveals varying eating patterns. I n Figure 1, the regressions of DM intake on the 28 days prior to parturition are shown for the four treatments. There was a marked decrease in DM consumption by cows on Treatments 2, 3, and 4 as parturition approached. The regression coefficients differ ( P < . 0 1 ) from each other and all except Treatment i differ ( P < . 0 1 )
TABLE 4. Effect of forage: concentrate ratio and dry matter intake prior to parturition on left abomasal displacement following parturition. Treatment a 2 Cows without LDA Cows with LDA Main effects
1.45 (10) b .92 (2) 1.29 (12)
3
4
Main effects
(kg DM/100 kg body weight) 1.55 (6) 1.65 (7) 1.45 (4) 1.46 (4) 1.52 (10) 1.59 (11)
1.55 (23) 1.28 (10)
Analysis of variance Source Treatment main effects LDA versus no LDA main effects Interaction Error
df
lV[.S.
F Ratio
2 1 2 27
.2663 .4734 .0944 .1256
2.12 3.77 .75
a There were no abomasa] displacements in Treatment 1. b Number in parenthesis is the number of observations represented in each mean. JOURNAL OF DAIRY ~OIENCE ~OL. 55, NO. 6
TABLE 5. Characteristics of cows with left abomasal displacements.
Days from
Cow 184 382 197 276 278 307 254 (died) 356 (died) 242 171
5~
.¢ ¢5
Treatment group
Lactation
Body wt a
Days cartied calf Size
Calf % Of dam's wt
Sex
calving Type of to L D A surgical diagnosis fixation c
4 3 3 4 4 3 3 2 4 2
3 2 3 1 1 2 1 2 2 3
(kg) 691.7 603.3 680.4 498.0 459.5 675.8 648.6 585.1 607.8 762.0
282 289 285 277 279 276 267 280 275 287
(kg) 54.9 54.4 50.3 39.0 46.3 51.7 40.8 49.9 44.0 54.4
7.9 9.0 7.4 7.8 10.1 7.7 6.3 8.5 7.2 7.1
F M ~V[ F iV[ M F M F ~
12 9 7 16 3 17 25 9 3 5
621.2
+279.7
48.6
7.9
a Taken immediately following calving. b RP, retained placenta; OF, off feed; Me, metritis; Ma, mastitis; Dys, dystocia. c OM, omentopexy; YA, ventral abomasopexy; LA~ left flank abomasopexy.
10.6
OM VA OM OM OM LA OM OM OM OM
Disorders b Concurrent
Previous
Me Me Me Me ]Vie, Ma
RP, O F
Me
Ma, R P Me, R P
Ma, Dys, Me RP, Ma, Me
RP
m ©
788
COPPOCK ET AL
from zero. On the day prior to parturition the average dry matter consumption of the cows in Treatment 1 was approximately 25% greater than the average dry matter consumption of the other three treatment groups. High grain feeding prepartum appears to depress total dry matter intake at parturition. Lower dry matter consumption of the more digestible rations may have resulted in less rumen fill and greater opportunity for migration of the abomasum. Johnson et al. (7) observed a decrease in voluntary intake of forage dry matter of .2 k g / d a y each week of the dry period when cows were fed 2.7 kg of concentrate per day. Additional data on the cows in which displacement of the abomasum occurred are shown in Table 5. All displacements were to the left and were diagnosed between 3 and 25 days postpartum. The average gestation length was 279.7 days, which is nearly identical to the value used for Holsteins of 280 days by the National Dairy H e r d Improvement Cooperative. Calf weights appear to reflect the lactation number of the dam. The data show that 9 of the 10 cows had concurrent problems and 4 of the 10 had had other disorders since calving. Nine of the 10 cows with L D A had metritis and 5 had retained placenta compared to 6 eases of metritis and 8 retained placentas among the 33 cows with no abomasal displacement. F r o m a study of health records of 202 cows which had had LDA, Robertson (15) found that 15% had a previous disorder and 23% had a concurrent disease. Cow 254 died on the second post-operative day of a coliform and streptococcal septicemia. Cow 356 died on the second post-operative day of a vegetative endoearditis, metritis, and abomasal ulcers. Some association between amount of concentrate in the ration, parturition, and the occurrence of displacement seems apparent from the data in this study. The average days from calving to L D A diagnosis was 10.6, which agrees with previous writers (13, 22) who found the highest incidence within 30 days post-calving. However, in other reports (5, 8) peak concentrate intakes have not been attained until weeks 8 to 12 after calving, even though both concentrate and forage were fed nearly ad libitum. Thus, the interval characterized by the greatest occurence of displacements does not coincide with the interval of greatest concentrate intake. Nevertheless, these results lend credence to the conclusions of Svendsen (19, 20) that high concentrate diets fed near parturition provide conditions conducive to the occurrence of abomasal displacement. JOURNAL OF DAIRY SCIENCE VOL. 55, NO. 6
The practice of lead feeding became popular about 10 years ago following the recognition that many cows had the ability to produce at much higher levels if additional energy were provided in the form of grain during the first p a r t of lactation (6). I t seemed reasonable to use lead feeding prepartum to facilitate adjustment to higher grain feeding postpartum, and this approach has been recommended by several writers (1, 14, 17). However, at that time the assumed advantage of conditioning cows before calving was not tested a p a r t from high grain feeding following calving. Recently, Emery et al. (2) and Gardner (4) presented evidence which showed no benefit from lead feeding if cows were fed well following calving and were in good condition in late pregnancy. Recent energy metabolism studies at Beltsville (3) showed that the energy requirement for the last 2 to 3 months of gestation is no more than 10 to 20% of the cow's maintenance requirement instead of the 60 to 70% suggested by Morrison (11) and 30% by NRC (12). A comparison of the energy consumed using values from the recent NRC (12) publication to estimate the digestible energy (DE) content of the feeds fed in this study and to estimate the DE required for maintenance shows that the average DE consumed was 155, 138, 159, and 173% of that required for maintenance for the four groups during the 28 days preceding parturition. Consequently, the requirements for maintenance plus pregnancy can easily be met by rations high in good quality forage. Although many high producing dairy cows must rely on body energy reserves in early lactation to support milk production and these reserves should be replenished before the next parturition, the metabolism trials of Moe et al. (10) show that the energetic efficiency of fat deposition while the cow is lactating is about 82% compared to 59% while the cow is dry. Therefore, it would a p p e a r to be more efficient energetically to replenish lipid reserves in late lactation than in the dry period. While some dry period is probably necessary for most cows, it is neither necessary nor energetically efficient to use the dry period as a time for replenishment of nutrient reserves. I t is possible that the body condition of the cow in late pregnancy may govern the type of production response to lead feeding. The energy consumed by a dry pregnant cow in excess of the maintenance requirement can only be deposited as fat. The enzymes in body tissues that function in fat deposition are not the same as those which serve to mobilize fat
FORAGE-CONCENTRATE
for the secretion of milk in early lactation when energy requirements usually exceed the ability of the cow to eat feed. I n effect, feeding grain at high levels before calving may increase the stress on the cow at p a r t u r i t i o n when body metabolism must change direction f r o m fat deposition to fat mobilization, as well as provide a rumen fermentation medium which is conducive to a high occurrence of abomasal displacement. The conditions predisposing a cow to L D A seem to be enhanced by the feeding of a high p r o p o r t i o n of concentrate p r i o r and immediately following calving. W h e t h e r a constant ratio of f o r a g e to concentrate is used as in this study or an increasing p r o p o r t i o n as in lead feeding, abomasal disorders occur most often on the high grain diets. The theory of lead feeding seems to have evolved as an extension of the high production response obtained with higher concentrate feeding postpartum. Although it now seems necessary to feed high concentrate to high producing cows postpartum, there seems little reason to continue the practice of lead feeding p r e p a r t u m if cows are in good condition at drying off. E x p e r i mental data now available indicate lead feeding may be a contributing factor to the occurence of abomasal displacement.
Acknowledgments The authors wish to express their appreciation to Mrs. Theresa Frazer for help with many details associated with the collection and editing of the data in this study.
References (1) Cason, J. L., R. F. Davis, R. W. Hemken, J. H. Vandersall, and C. D. Caskey. 1965. Economical grain feeding for dairy cows. Univ. Maryland Ext. Bull., 202. (2) Emery, R. S., H. D. Hafs, D. Armstrong, and W. W. Snyder. 1969. Prepartum grain feeding effects on milk production, mammary edema, and incidence of diseases. J. Dairy Sci., 52: 345. (3) Flatt, W. P., P. W. Moe, and L. A. Moore. 1969. Influence of pregnancy and ration composition on energy utilization by dairy cows. European Ass. Animal Prod., Publ. ]2, p. 123. Orrel Press Ltd. (4) Gardner, R. W. 1969. Interactions of energy levels offered to Holstein cows prepartum and postpartum. 2. Production responses and blood composition changes. J. Dairy Sci., 52: 1973. (5) Hemken, R. W., and J. H. Vandersail. 1965. Intake levels during early lactation of the dairy cow. Prec. Maryland Nutrition Conf., p. 69. (6) Huffman, C. F. 1961. High-level grain feeding for dairy cows. J. Dairy Sci., 44 : 2113.
RATIO
789
(7) Johnson, W. L., G. W. Trimberger, M. J. Wright, L. D. Van Vleck, and C. R. Henderson. 1966. Voluntary intake of forage by Holstein cows as influenced by lactation, gestation, body weight and frequency of feeding. J. Dairy Sci., 49:856. (8) Jumah, H. F., B. R. Poulton, and W. P. Apgar. 1965. Energy and protein utilization during lactation. J. Dairy Sci., 48: 1210. (9) Mather, M. ~., and R. S. Dedrlek. 1966. Displacement of the abomasum. Cornell Vet., 56: 323. (10) Moe, P. W., H. F. Tyrrel], and W. P. Flatt. 1971. Energetics of body tissue mobilization. J. Dairy Sei., 54: 548. (11) Morrison, F. B. 1956. Feeds and Feeding. 22nd Edition. The Morrison Publishing Co., Ithaca, Mew York. (12) National Academy of Sciences--National Research Council. 1971. Nutrient requirements of domestic animals. Nutrient requirements of dairy cattle. No. 3. Washington, D.C. (13) Neal, P. A. 1964. Some critical observations on the etiology of displacement of the abomasum in the dairy cow. Nor& Vet.Med., 16: 361. (14) Reid, 5. T. 1961. Problems of feed evaluation related to feeding of dairy cows. J. Dairy Sci., 44: 2122. (15) Robertson, J. McD. 1968. Left displacement of the bovine abomasum: eplzootiologic factors. Amer. J. Vet. Res., 29: 421. (16) Robertson, J. M., and W. B. Boucher. 1966. Treatment of left displacement of the bovine abomasum. J. Amer. Vet. Med. Ass., 149: 1423. (17) Slack, S. T., J. ]~. Stone, and W. G. Merrill. 1965. Feeding the dairy cow for maximum returns. Cornell Ext. Ball., 1156. (18) Smith, N. E. 1971. Feed efficiency in intensive milk production. U. Calif. 10th Ann. Dairy Cattle Day Rep., p. 40. (19) Svendsen, Per. 1969. Etiology and pathogenesis of abomasal displacement in cattle. Nord. ¥et.-Med., 21: Supplement I. (20) Svendsen, Per. 1970. Abomasal displacement in cattle. The concentrations of volatile fatty acids in ruminal and abomasal contents and their influence on abomasal motility and the flow-rate of the abomasal contents. Nord. Vet.-Med., 22: 571. (21) Van Soest, P. J. 1967. Development of a comprehensive system of feed analyses and its application to forages. J. Animal Sci., 26 : 119. (22) Whitlock, R. H. 1969. Diseases of the abomasum associated with current feeding practices. J. Amer. Vet. Med. Ass., 154: 1203. (23) Woelffer, E. A. ]962. Stomachs out of order and out of place. Hoard's Dairyman, 107 : 1262. JOURNAL OF DAIRY SCIENCE VOL. 55, NO. 6