- Email: [email protected]
Effect of sire of foetus on current and subsequent milk yield of the dam
Livestock Production Science, 20 (1988) 107-117 Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
107
Effect of Sire of Foetus on Current and Subsequent Milk Yield of the D a m R. SANER and C. GAILLARD
Institute o/Animal Breeding, Veterinary Faculty, University o/Berne, Bremgartenstrasse 109a, CH-3012 Berne (Switzerland) (Accepted 29 March 1988)
ABSTRACT Saner, R. and Gaillard, C., 1988. Effect of sire of foetus on current and subsequent milk yield of the dam. Livest. Prod. Sci., 20: 107-117. The influence of the sire of foetus and the birth weight of the calf on the dam's current and subsequent milk production was investigated in Simmental cows. The study was based on milk yields of 19 339 primiparous and 53 942 multiparous dams carrying foetuses from 260 sires of 5 different Red Holstein × Simmental breed groups. The foetal-sire effect on milk production was calculated as the correlation between the record of the dam, corrected for various factors, and the genotype of the sire of foetus. These correlations were small for the subsequent as well as for the current lactation, and ranged from 0.04 to 0.11. The milk yields of multiparous cows were affected by the breed of sire of foetus. This was, however, only occasionally the case in primiparous cows. Significant but small effects of calf birth weight were found only in multiparous cows. Although the sire of foetus has a significant effect on the milk yield of the dam, genetic implications seem unimportant in sire evaluation, since the largest difference between sire of foetus averaged only 40 kg for the standard lactation in primiparous cows. These effects are somewhat larger for the 100-day milk yield (90 kg).
INTRODUCTION T h e r e l a t i o n s h i p b e t w e e n t h e f o e t u s a n d its d a m d u r i n g p r e g n a n c y a n d carr y o v e r of t h i s r e l a t i o n s h i p p o s t p a r t u m h a s long b e e n r e c o g n i z e d for m a n y diff e r e n t t r a i t s , a m o n g o t h e r s , l a c t a t i o n yield in c a t t l e ( S k j e r v o l d a n d F i m l a n d , 1975; A d k i n s o n et al., 1977; Skjervold, 1979; T h a t c h e r et al., 1980; V a n V l e c k a n d J o h n s o n , 1980; M o r e O ' F e r r a l l et al., 1985). I n rats, m i c e a n d s m a l l r u m i n a n t s t h e t o t a l b i r t h w e i g h t ( w e i g h t of foetus, p l a c e n t a , etc. ) a n d / o r t h e n u m b e r of f o e t o - p l a c e n t a l u n i t s h a v e a s i g n i f i c a n t i n f l u e n c e on t h e d e v e l o p m e n t a n d s e c r e t i o n a c t i v i t y of t h e m a m m a r y g l a n d ( A n d e r s o n , 1975; H a y d e n et al., 1980; B u t l e r et al., 1981; S c h a m s et al., 1984).
0301-6226/88/$03.50
© 1988 Elsevier Science Publishers B.V.
108
In these species, serum levels of placental lactogen hormone are positively related to the number of foetuses (Steine, 1975; Thompson and Anderson, 1977; Buttle et al., 1978; Hayden et al., 1979; Land and Robinson, 1985). Hayden et al. (1979) demonstrated a correlation of 0.69 between the litter size and the serum level of placental lactogen hormone in goats. Purification of bovine placental lactogen (bPL) was first reported by Bolander et al. (1976). This polypeptide hormone of the foetal placenta was found in foetal, but not always in maternal sera (Buttle and Forsyth, 1976; Thatcher et al., 1980; Schellenberg and Friesen, 1982; Schams et al., 1984; Duello et al., 1986 ). In small ruminants as well as in cattle, binucleate cells from the trophoblast (foetal tissue) are able to migrate across the microvillar junction into the epithelial (maternal) tissue of the placenta (Wooding and Wathes, 1980; Wooding, 1983, 1984; Duello et al., 1986; Lee et al., 1986). These binucleate cells are able to transport and release bPL and other hormones (Reimers et al., 1985). The migration into maternal tissue of the foetal cells carrying and releasing bPL may explain the interaction between foetus and milk yield of the dam. Arima and Bremel (1983) isolated 3 different types of bPL from cattle cotyledons and demonstrated that two of the three forms had both bovine prolactin and bovine growth hormone-like activities. The main objective of this study was to estimate whether the sire of the foetus a n d / o r the birth weight of the calf has an influence on the dam's current and subsequent milk production. MATERIAL AND METHODS
The data used in this study were monthly milk-yield records from the milkrecording scheme of the Swiss Simmental Breeding Association and information from the progeny testing program for ease of calving in young AI bulls (Gaillard and Chavaz, 1982 ), i.e. only cows which were bred with unproven AI bulls were involved. Statistical evaluations were performed on the data from separate years, because year and sire effects are completly confounded. Separate analyses were also carried out for primiparous and multiparous cows. The distribution of the material subjected to analysis is shown in Table 1. Sires of foetuses were classified according to their proportion of Red Holstein blood into the following 5 groups: Si = Simmental bulls; 1/4RH = bulls with 19-37% Red Holstein blood; 1/2RH = bulls with 38-62% Red Holstein blood; 3/4RH --- bulls with 63-75% Red Holstein blood; RH -- bulls with more than 75% Red Holstein blood. The effect of the sire of foetus was analysed on the subsequent milk production ( 100- and 305-day yield) as well as at the end of the current lactation. The ultimate 60-day milk yield was calculated as the sum of the last two monthly
109 TABLE 1 Number of sires and dams of foetuses pooled over the 3 years (1980-1982 ) Breed group 1
Sires
Primiparous dams
Multiparous dams
Si 1/4 RH 1/2RH 3/4RH RH
93 39 54 52 22
5005 2508 4783 5244 1799
20878 7040 10236 8999 6839
1Si = Simmental; RH-- Red Holstein.
records and the penultimate 60-day milk yield as the sum of the last but two and the last but three monthly records. Persistency at the end of lactation was described by the linear regression through the last four monthly records. Least-squares procedures as described by Harvey (1987) were applied on various fixed and mixed models. In the analyses of factors affecting the subsequent milk yield, the following effects were considered: breed of sire of foetus, sire within breed (random effect), region, calving month, herd class for milk production, linear and quadratic regression on age at calving, dam breeding value for milk, previous days open and days dry of the dam. When the influence of the birth weight of the calf on the milk production of the dam was investigated, the above-mentioned model was modified by dropping breed and sire within breed effects but adding birth weight as a continuous independent variable. In the evaluation of factors affecting the end of the current lactation the above model was adapted by replacing the regression on the days dry by a linear and quadratic regression on gestation length at the last but three monthly records. In order to avoid problematical corrections for twinning, deformed calves, ceasarean, dystocia etc. only cows with normal birth (Gaillard and Chavaz, 1982) of a single calf and with a lactation length of at least 270 days were considered in the evaluation. At least 200 offspring were required from each sire. RESULTS AND DISCUSSION
Overall means and standard deviations of the 100- and 305-day milk yields are fairly consistent with the population means of the Swiss Simmental cattle (Schweizerischer Fleckviehzuchtverband, 1983; Saner, 1987). Results from analyses of variance showed that nearly all factors included in the model had a significant influence on the different milk-yield traits (Saner, 1987). Significant values were partly expected because of the large number of
110
records involved in the analyses. The preceding dry period only has a significant effect on the 100-day milk production but not on the standard lactation. Days open of the previous lactation has, however, a significant influence on the 305-day milk yield and practically none on the first 100-day production. The h 2 values for the penultimate, the ultimate 60-day milk yield and for persistency at the end of lactation, estimated in a preliminary analysis were 0.32 (SE:0.04), 0.31 (SE;0.03)and 0.11 (SE:0.02), respectively.
Foetal influence on subsequent lactation yields Breed of sire of foetus Although the effects of breed of the sire of foetuses are significant in most cases, they are of minor importance especially for the 305-day milk production (Table 2 ). These effects are always larger on the 100-day than on 305-day milk yield. It seems that Red Holsteins as a breed of sire of foetuses favourably affect the 100-day milk yield, whereas the Simmental breed has rather a negative effect. Average differences between these two breeds amount to 60 kg for multiparous and 24 kg for primiparous cows, respectively, for the 100-day but only 11 kg and 7 kg for the 305-day milk yield. These results indicate that at least for standard lactations, the breed of sire of foetuses has no relevant consequences for estimations of breeding values.
Foetal sire effects The effects of the sire of foetus are, with one exception, always significant. The foetal-sire effect on milk production was calculated as the correlation between the record of the dam, corrected for the various factors included in the model, and the breeding value for the specific foetal effect on milk production TABLE2 Effect of the breed of the sire of foetus on a subsequent lactation yield (average of the 3 years) Breed of sire
Milk yield in kg (LS Constants) ~ Multiparous
Si 1/4RH 1/2RH 3/4 R H RH
Primiparous
100-day
305-day
100-day
305-day
-24 -11 - 6 3 36
-
-15 4 - 4 5 9
-6
1 2 4 3 10
1 2 2 1
~SE of the annual 100- and 305-day milk yields ranged from 3.2 to 8.8 kg and from 2.2 to 5.1 kg, respectively.
111 TABLE 3 Correlations between breeding value for the specific foetal effect on milk production of the sire of foetus and milk yield of the subsequent lactation of the dam (average of the 3 years) Parity
100-day milk yield 305-day milk yield
Multiparous
Primiparous
0.06 0.05
0.11 0.07
TABLE 4 Regression coefficients for milk yield of the dam on birth weight on her calf (kg milk kg-1 birth weight) 1 Year
1980 1981 1982
Multiparous
Primiparous
100 day
305 day
100 day
305 day
1.33"** 1.32"** 1.62"**
0.51" 0.46* 0.98***
0.19 NS 1.24"** 0.58 NS
0.03 NS 0.05 NS 0.29 NS
1NS = P > 0.05; * = P < 0.05; *** = P < 0.001.
of the sire of the foetus as presented by Skjervold and Fimland (1975) (Table 3 ). The correlation coefficients are lower in multiparous than in primiparous dams and correlations for 100-day milk yield are somewhat larger than those for the 305-day ones. These figures suggest that the sire of foetus accounts for a very small amount (1% and less) of the variation in the milk yield. These figures are in agreement with most studies summarized in Van Vleck and Johnson (1980). In separate analyses, least squares constants for sire of foetus effects were estimated within years and breed groups. The mean difference between the two extreme sire constants average 70 kg for the 100-day and 44 kg for the 305day milk yield in multiparous dams; these figures are 90 kg and 40 kg, respectively, for primiparous dams.
Birth weight The birth weight of the calf significantly affects the milk production of the dam only in multiparous cows (Table 4). This influence is more important for 100-day than for standard lactation yields. In primiparous cows, all but one of the regressions of milk production of the dam on birth weight of her calf are not significant. No explanation can be given as to why this one value is so extreme, the corresponding regression on the standard lactation is, however,
112
very small. These figures are all positive as in other studies too, but very much smaller (Thatcher et al., 1980). A possible reason why birth weight does not affect the milk yield in primiparous as much as in multiparous cows could be the lighter birth weight of the calves (40.6 versus 44.7 kg). In a preliminary analysis it could be shown that sex of calf had a significant effect on the 100-day milk yield only in multiparous dams and none in the other cases. Sex of calf has an indirect effect because weight of male calves is significantly larger than females.
Foetal effect on current lactation yields Breed of sire of foetus Breed of sire of foetus shows only a significant effect in multiparous cows, but the magnitude remains small (Table 5). The foetal effect is smaller on the penultimate 60-day milk yield than on the ultimate one. This can be explained by the younger age of the foetus and consequently also by a smaller placental volume. In contrast to the foetal effect on subsequent lactation it seems that the Red Holstein has an unfavourable effect on the end of the current lactation, whereas the Simmental shows a positive effect. Persistency at the end of lactation of cows inseminated with a RH bull is somewhat lower than with Simmental. Foetal-sire effects Foetal-sire effects were, with one exception, always significant (data not shown) and the magnitude was calculated as the coefficient of correlation between the genotype of the sire of the foetus and the milk production of the dam (Table 6). This genetic effect of the foetus on milk production seems to be the same in multiparous and primiparous cows and for all three traits. The figures for the ultimate 60-day milk yield are in good agreement with those estimated by Skjervold (1979) but the correlation coefficients for the penultimate 60day milk yield are larger. TABLE 5 Effect of the breed of the sire of foetus on current lactation in multiparous cows (averages of the LS constants over the 3 years) Performance
Breed Si
1/4 RH
3 Penultimate 60-day milk yield (kg) 6 15 6 Ultimate 60-day milk yield (kg) 0.035 0.006 Persistency (kg day- 1)
1/2 RH 1
-2 -0.014
3/4 RH
RH
-1
-10 -19 - 0.034
-1 0.007
113 TABLE 6 Average of the correlations between the breeding value for the specific foetal effect on milk production of the sire of foetus and milk yield at the end of the current lactation of the dam Performance
Multiparous
Primiparous
Penultimate 60-day milk yield (kg) Ultimate 60-day milk yield (kg) Persistency (kg day -1)
0.07 0.09 0.09
0.08 0.10 0.10
TABLE 7 Effect of birth-weight classes in multiparous dams (average of the 3 years) Performance
Ultimate 60-day milk yield (kg) Persistency (kgday -1)
Birth-weight classes (kg) 30
35
40
45
50
55
60
9 0.015
11 0.018
3 0.010
1 0.009
- 4 -0.003
- 12 - 0.033
- 8 -0.017
In separate analyses, the individual sire of foetus effects were calculated, as well as the difference between the two extreme sire constants within year and breed group. The average range is the same in both dam groups and amounts to 46.0 kg for the penultimate 60-day milk yield and 60.5 kg for the ultimate 60-day milk production.
Birth weight In preliminary analyses of variance where birth weight was considered as a continuous variable, this effect had no significant influence on the trait at end of the current lactation. The birth weight was then grouped in 7 classes (2832, 33-37..., 58-62 kg) and incorporated into the least squares model as a fixed effect. In primiparous cows, none of the traits of end of lactation are affected by the weight of foetus. This factor also has no effect upon the penultimate 60day milk yield of multiparous cows. Birth-weight classes have a significant effect on the ultimate 60-day milk yield and persistency at the end of lactation (Table 7 ). An explanation as to why the effect of the weight of foetus on milk production during the penultimate 60 days of lactation is not significant, whereas during the ultimate 60 days it is significant, is the exponential growth of the foetus. During the penultimate 60 days the weight of foetus increases only about 3.5 kg whereas in the ultimate 60 days this increases by about 12.5 kg and starts to compete with milk production.
114 CONCLUSION
The results of this study suggest that there is a significant effect of the sire of foetus on the subsequent lactation and on the end of the current lactation of the dam. The physiological explanation of foetal effects may be due to foetal binucleate cells migrating across the foetal-maternal boundary and delivering b P L to the maternal circulation (Duello et al., 1986). The 3 distinct bPL forms show differing activities, which could be due to genetic differences (Arima and Bremel, 1983). Furthermore, Guilbault et al. (1985a,b) were able to show that variation of breed of sire of foetus influenced hormone concentrations of both maternal (progesteron, 15-keto-13,14-dihydro-prostaglandin F2a) and conceptus (estrogen) origin during the preparturient period. Variations in circulating estrogens could contribute to significant variations in milk production of the dam. The correlations between the breeding value for the specific foetal effect on milk production of the sire of foetus and the milk yield of the dam are, however, small and range from 0.05 to 0.10. The breed of sire of foetus affects dam milk production in multiparous cows but only occasionally affects this in primiparous cows. The difference between the two parity groups could be due to the small breed effects and the large number of records in multiparous compared with primiparous cows. The foetal effect of the breed of sire of foetus seems to be somewhat smaller between Simmental and Red Holstein than between sires of foetus within breeds. Although the sire of the foetus has a significant effect, the genetic implications seem relatively unimportant in sire evaluation, since the largest difference between sire of foetus averages only 40 kg for the standard lactation in primiparous cows. The gain in accuracy, when the sire of foetuses is incorporated in the sire evaluation model does not outweigh the additional costs (labour for getting all sire of foetus information, computer, etc. ). The use of the birth weight of the calf as alternative to correct milk yield of the dam does not contribute very much either, because it does not affect the production of primiparous cows. Further, a reliable and systematic registration of birth weights could be hard to achieve in practice. It might be cautious not to select cows based only on the 100-day milk yield because the carry-over effect of the sire of foetus can bias the production record to some extent. ACKNOWLEDGEMENTS
The authors thank Dr. J. Crettenand of the Simmental Herdbook, J. Chavaz and R. Weber of the Swiss Association of AI for making the data available.
115 REFERENCES Adkinson, R.W., Wilcox, C.J. and Thatcher, W.W., 1977. Effects of sire of fetus upon subsequent production and days open of the dam. J. Dairy Sci., 60: 1964-1969. Anderson, R.R., 1975. Mammary gland growth in the hypophysectomized pregnant rat. Proc. Soc. Exp. Biol. Med., 148: 283. Arima, Y. and Bremel, R.D., 1983. Purification and characterization of bovine placental lactogen. Endocrinology, 113: 2186-2194. Bolander, Jr., F.F., Ulberg, L.C. and Fellows, R.E., 1976. Circulating placental lactogen levels in dairy and beef cattle. Endocrinology, 99: 1273-1278. Butler, W.R., Fullenkamp, S.M., Cappiello, L.A. and Handwerger, S., 1981. The relationship between breed and litter size in sheep and maternal serum concentrations of placental lactogen, estradiol and progesterone. J. Anim. Sci., 53: 1077-1081. Buttle, H.L. and Forsyth, I.A., 1976. Placental lactogen in the cow. J. Endocrinol., 68: 141-146. Buttle, H.L., Cowie, A.T., Jones, E.A. and Turvey, A., 1978. The contribution of placental hormones to the development of the mammary glands in goats. J. Endocrinol., 77: 59. Duello, T.M., Byatt, J.C. and Bremel, R.D., 1986. Immunohistochemical localisation of placental lactogen in binucleate cells of bovine placentomes. Endocrinology, 119: 1351-1355. Gaillard, C. and Chavaz, J., 1982. Genetic parameters for calving performance in Simmental cattle. Proc. 2nd World Congr. Genet. Appl. Livest. Prod., Madrid, 8: 189-194. Guilbault, L.A., Thatcher, W.W., Collier, R.J. and Wilcox, C.J., 1985a. Periparturient endocrine changes of conceptus and maternal units in Holstein heifers bearing genetically different conceptuses. J. Anim. Sci., 61: 1505-1515. Guilbault, L.A., Thatcher, W.W., Collier, R.J., Wilcox, C.J. and Drost, M., 1985b. Carry-over effects of periparturient endocrine changes on postpartum reproductive function of Holstein heifers bred to genetically different service sires. J. Anim. Sci., 61: 1516-1526. Harvey, W.R., 1987. Users guide for LSMLMW: Mixed model least-squares and maximum likelihood computer program, 10/1985. Revised January, 1987. Ohio State University, Columbus, Ohio 42210 (mimeo.). Hayden, T.J., Thomas, C.R. and Forsyth, I.A., 1979. Effect of number of young born (litter size) on milk yield of goats: role for placental lactogen. J. Dairy Sci., 62: 53-57. Hayden, T.J., Thomas, C.R., Smith, S.V. and Forsyth, I.A., 1980. Placental lactogen in the goat in relation to stage of gestation, number of fetuses, metabolites, progesterone and time of day. J. Endocrinol., 86: 279-290. Land, R.B. and Robinson, D.W., 1985. Genetics of reproduction in sheep. Butterworths, Lee, C.S. Gogolin-Ewens, K. and Brandon, M.R., 1986. Comparative studies on the distribution of binucleate cells in the placentae of the deer and cow using the monoclonal antibody, SBU3. J. Anat., 147: 163-179. More O'Ferrall, G.J., Cunningham, E.P. and Badi, A.M., 1985. Does breed of bull affect production from Friesian Cows? Farm Food Res., 16: 24-26. Reimers, T.J., Ullmann, M.B. and Hansel, W., 1985. Progesterone and prostanoid production by bovine binucleate trophoblastic cells. Biol. Reprod., 33: 1227-1236. Saner, R., 1987. Abkl~irungen tiber den Einfluss des Vaters des Foeten auf die Milchleistung der Mutter beim Schweizerischen Fleckvieh. Dissertation Universita't Bern. Schams, D., Rtisse, I., Schallenberger, E., Prokopp, S. and Chan, J.S.D., 1984. The role of steroid hormones, prolactin and placental lactogen on mammary gland development in ewes and heifers. J. Endocrinol., 102: 121-130. Schellenberg, C. and Friesen, H.G., 1982. The bioassay of bovine placental lactogen. Endocrinology, 111: 2125-2128. Schweizerischer Fleckviehzuchtverband, 1983. Ergebnisse der Milchleistungsprtifungen beim Simmentaler Fleckvieh in Kontrolljahr, 1982/83. Simmentaler Fleckvieh, 7: 40-65.
116 Skjervold, H., 1979. Effect of foetal genotype on maternal performance. Indian J. Anim. Genet. Breeding, 1: 23-29. Skjervold, H. and Fimland, E., 1975. Evidence for a possible influence of the fetus on the milk yield of the dam. Z. Tierz. Zuechtungsbiol., 92" 245-251. Steine, T.A., 1975. Einskfld-kontrollar of del-laktasjonar hos geit (Test day records and part lactations in goat). Sci. Rep. Agric. Univ. Norway, 54:(31 ): 1-25. Thatcher, W.W., Wilcox, C.J., Collier, R.J., Eley, D.S. and Head, H.H., 1980. Bovine conceptusmaternal interactions during the pre- and postpartum periods. J. Dairy Sci., 63: 1530-1540. Thompson, L.J. and Anderson, R.R., 1977. Effect of pregnancy on lactation in mice. J. Dairy Sci., 60: 126-128. Van Vleck, L.D., 1978. A genetic model involving fetal effects and traits of the dam. Biometrics, 34: 123-!27. Van Vleck, L.D. and Johnson, L.P., 1980. Genetic and economic implications of fetal effects on the dam. J. Dairy Sci., 63: 1483-1491. Wooding, F.B.P., 1983. Frequency and localization of binucleate cells in the placentomes of ruminants. Placenta, 4: 527-540. Wooding, F.B.P., 1984. Role of binucleate cell fusion at implantation in the sheep. Am. J. Anat., 170: 233-250. Wooding, F.B.P. and Wathes, D.C., 1980. Binucleate cell migration in the bovine plazentome. J. Reprod. Fertil., 59: 425-430. RESUME Saner, R. and Gaillard, C., 1988. Effet du p~re du foetus sur la production laiti~re maternelle de la lactation en cours et de la suivante. Livest. Prod. Sci., 20:107-117 (en anglais). L'influence du p~re du foetus et du poids du veau h la naissance sur la production laiti~re de la lactation en cours et de la suivante a ~t~ Studi~e dans la race tachet~e rouge du Simmental. L'~tude se base sur les productions laiti~res de 19 339 primipares et 53 942 multipares portant des foetus de 260 p~res diff~rents, comprenant 5 groupes raciques provenant du croisement Red Holstein × Simmental. La correlation entre le rendement laitier de la mbre (corrigd pour diff~rents facteurs) et le genotype du pbre du foetus a ~t~ le param~tre utilis~ pour ~valuer l'effet du foetus sur la production laiti~re. Ces correlations sont faibles aussi bien pour la lactation en cours que pour la suivante, elles varient entre 0.04 et 0.11. La production laiti~re des vaches multipares est influencde par la race du p~re du foetus. Chez les primipares cela n'est le cas qu'occasionellement. L'effet du poids de veau h la naissance est significatif mais faible et ne se manifeste que chez les multipares. Bien que le p~re du foetus ait un effet significatif sur la production laitibre de la m~re, les consdquences g~nStiques ne semblent pas importantes pour l'~valuation de la valeur d'$1evage des taureaux. En effet, la plus grande difference observ~e ne s'~lbve qu'~ 40 kg pour les lactations standards chez les primipares. Ces effets sont un peu plus importants pour le rendement laitier 100 jours (90 kg). KURZFASSUNG Saner, R. und Gaillard, C., 1988. Einfluss des Vaters des Foeten auf die laufende und folgende Laktationsleistung der Mutter. Livest. Prod. Sci., 20:107-117 (auf englisch). Der einflussdes Vaters des Foeten und des Geburtsgewichtes des Kalbes auf die laufende und folgendeLaktationsleistungvon Simmentalerkiihen wurde untersucht.Die Auswertungen stfitzen
117 sich auf Milchleistungen von 19 339 erstlaktierenden un 53 942 ~ilteren Kiihen, die Foeten von 260 Vatertieren mit unterscheidlichem Red Holstein-Anteiltrugen. Der foetale Vatereffekt wurde durch die Korrelation zwischen der M~lchleistung der Mutter, korrigiert fiir mehrere Einflussfaktoren, und dem Genotyp des Vaters des Foeten bestimmt. Diese Korrelationen waren sowohl ftir die laufende wie ftir die folgende Laktation klein und lagen zwischen 0.04 und 0.11. Die Leistung von ~ilteren Ktihen wurde durch die Rasse des Vaters des Foeten beeinflusst; dies war bei Erstlingsktihen nut zeitwiese der Fall. Das Geburtsgewicht des Kalbes hatte ausschliesslich bei ~lteren Kiihen einen signifikanten, abet nur geringen Effekt auf die Milchleistung. Obgleich der Vater des Foeten einen signifikanten Einfluss auf die Milchleistung der Mutter austibt, scheinen die genetischen Konsequenzen fiir die Zuchtwertschiitzung der Stiere unwesentlich zu sein, da bei Standardlaktationen von Erstlingskiihen der grSsste Unterschied zwischen V~iter der Foeten im Mittel nur 40 kg betr~igt. Die Unterschiede sind etwas geringer, wenn es sich um 100-Tage-Leistungen handelt (90 kg).
107
Effect of Sire of Foetus on Current and Subsequent Milk Yield of the D a m R. SANER and C. GAILLARD
Institute o/Animal Breeding, Veterinary Faculty, University o/Berne, Bremgartenstrasse 109a, CH-3012 Berne (Switzerland) (Accepted 29 March 1988)
ABSTRACT Saner, R. and Gaillard, C., 1988. Effect of sire of foetus on current and subsequent milk yield of the dam. Livest. Prod. Sci., 20: 107-117. The influence of the sire of foetus and the birth weight of the calf on the dam's current and subsequent milk production was investigated in Simmental cows. The study was based on milk yields of 19 339 primiparous and 53 942 multiparous dams carrying foetuses from 260 sires of 5 different Red Holstein × Simmental breed groups. The foetal-sire effect on milk production was calculated as the correlation between the record of the dam, corrected for various factors, and the genotype of the sire of foetus. These correlations were small for the subsequent as well as for the current lactation, and ranged from 0.04 to 0.11. The milk yields of multiparous cows were affected by the breed of sire of foetus. This was, however, only occasionally the case in primiparous cows. Significant but small effects of calf birth weight were found only in multiparous cows. Although the sire of foetus has a significant effect on the milk yield of the dam, genetic implications seem unimportant in sire evaluation, since the largest difference between sire of foetus averaged only 40 kg for the standard lactation in primiparous cows. These effects are somewhat larger for the 100-day milk yield (90 kg).
INTRODUCTION T h e r e l a t i o n s h i p b e t w e e n t h e f o e t u s a n d its d a m d u r i n g p r e g n a n c y a n d carr y o v e r of t h i s r e l a t i o n s h i p p o s t p a r t u m h a s long b e e n r e c o g n i z e d for m a n y diff e r e n t t r a i t s , a m o n g o t h e r s , l a c t a t i o n yield in c a t t l e ( S k j e r v o l d a n d F i m l a n d , 1975; A d k i n s o n et al., 1977; Skjervold, 1979; T h a t c h e r et al., 1980; V a n V l e c k a n d J o h n s o n , 1980; M o r e O ' F e r r a l l et al., 1985). I n rats, m i c e a n d s m a l l r u m i n a n t s t h e t o t a l b i r t h w e i g h t ( w e i g h t of foetus, p l a c e n t a , etc. ) a n d / o r t h e n u m b e r of f o e t o - p l a c e n t a l u n i t s h a v e a s i g n i f i c a n t i n f l u e n c e on t h e d e v e l o p m e n t a n d s e c r e t i o n a c t i v i t y of t h e m a m m a r y g l a n d ( A n d e r s o n , 1975; H a y d e n et al., 1980; B u t l e r et al., 1981; S c h a m s et al., 1984).
0301-6226/88/$03.50
© 1988 Elsevier Science Publishers B.V.
108
In these species, serum levels of placental lactogen hormone are positively related to the number of foetuses (Steine, 1975; Thompson and Anderson, 1977; Buttle et al., 1978; Hayden et al., 1979; Land and Robinson, 1985). Hayden et al. (1979) demonstrated a correlation of 0.69 between the litter size and the serum level of placental lactogen hormone in goats. Purification of bovine placental lactogen (bPL) was first reported by Bolander et al. (1976). This polypeptide hormone of the foetal placenta was found in foetal, but not always in maternal sera (Buttle and Forsyth, 1976; Thatcher et al., 1980; Schellenberg and Friesen, 1982; Schams et al., 1984; Duello et al., 1986 ). In small ruminants as well as in cattle, binucleate cells from the trophoblast (foetal tissue) are able to migrate across the microvillar junction into the epithelial (maternal) tissue of the placenta (Wooding and Wathes, 1980; Wooding, 1983, 1984; Duello et al., 1986; Lee et al., 1986). These binucleate cells are able to transport and release bPL and other hormones (Reimers et al., 1985). The migration into maternal tissue of the foetal cells carrying and releasing bPL may explain the interaction between foetus and milk yield of the dam. Arima and Bremel (1983) isolated 3 different types of bPL from cattle cotyledons and demonstrated that two of the three forms had both bovine prolactin and bovine growth hormone-like activities. The main objective of this study was to estimate whether the sire of the foetus a n d / o r the birth weight of the calf has an influence on the dam's current and subsequent milk production. MATERIAL AND METHODS
The data used in this study were monthly milk-yield records from the milkrecording scheme of the Swiss Simmental Breeding Association and information from the progeny testing program for ease of calving in young AI bulls (Gaillard and Chavaz, 1982 ), i.e. only cows which were bred with unproven AI bulls were involved. Statistical evaluations were performed on the data from separate years, because year and sire effects are completly confounded. Separate analyses were also carried out for primiparous and multiparous cows. The distribution of the material subjected to analysis is shown in Table 1. Sires of foetuses were classified according to their proportion of Red Holstein blood into the following 5 groups: Si = Simmental bulls; 1/4RH = bulls with 19-37% Red Holstein blood; 1/2RH = bulls with 38-62% Red Holstein blood; 3/4RH --- bulls with 63-75% Red Holstein blood; RH -- bulls with more than 75% Red Holstein blood. The effect of the sire of foetus was analysed on the subsequent milk production ( 100- and 305-day yield) as well as at the end of the current lactation. The ultimate 60-day milk yield was calculated as the sum of the last two monthly
109 TABLE 1 Number of sires and dams of foetuses pooled over the 3 years (1980-1982 ) Breed group 1
Sires
Primiparous dams
Multiparous dams
Si 1/4 RH 1/2RH 3/4RH RH
93 39 54 52 22
5005 2508 4783 5244 1799
20878 7040 10236 8999 6839
1Si = Simmental; RH-- Red Holstein.
records and the penultimate 60-day milk yield as the sum of the last but two and the last but three monthly records. Persistency at the end of lactation was described by the linear regression through the last four monthly records. Least-squares procedures as described by Harvey (1987) were applied on various fixed and mixed models. In the analyses of factors affecting the subsequent milk yield, the following effects were considered: breed of sire of foetus, sire within breed (random effect), region, calving month, herd class for milk production, linear and quadratic regression on age at calving, dam breeding value for milk, previous days open and days dry of the dam. When the influence of the birth weight of the calf on the milk production of the dam was investigated, the above-mentioned model was modified by dropping breed and sire within breed effects but adding birth weight as a continuous independent variable. In the evaluation of factors affecting the end of the current lactation the above model was adapted by replacing the regression on the days dry by a linear and quadratic regression on gestation length at the last but three monthly records. In order to avoid problematical corrections for twinning, deformed calves, ceasarean, dystocia etc. only cows with normal birth (Gaillard and Chavaz, 1982) of a single calf and with a lactation length of at least 270 days were considered in the evaluation. At least 200 offspring were required from each sire. RESULTS AND DISCUSSION
Overall means and standard deviations of the 100- and 305-day milk yields are fairly consistent with the population means of the Swiss Simmental cattle (Schweizerischer Fleckviehzuchtverband, 1983; Saner, 1987). Results from analyses of variance showed that nearly all factors included in the model had a significant influence on the different milk-yield traits (Saner, 1987). Significant values were partly expected because of the large number of
110
records involved in the analyses. The preceding dry period only has a significant effect on the 100-day milk production but not on the standard lactation. Days open of the previous lactation has, however, a significant influence on the 305-day milk yield and practically none on the first 100-day production. The h 2 values for the penultimate, the ultimate 60-day milk yield and for persistency at the end of lactation, estimated in a preliminary analysis were 0.32 (SE:0.04), 0.31 (SE;0.03)and 0.11 (SE:0.02), respectively.
Foetal influence on subsequent lactation yields Breed of sire of foetus Although the effects of breed of the sire of foetuses are significant in most cases, they are of minor importance especially for the 305-day milk production (Table 2 ). These effects are always larger on the 100-day than on 305-day milk yield. It seems that Red Holsteins as a breed of sire of foetuses favourably affect the 100-day milk yield, whereas the Simmental breed has rather a negative effect. Average differences between these two breeds amount to 60 kg for multiparous and 24 kg for primiparous cows, respectively, for the 100-day but only 11 kg and 7 kg for the 305-day milk yield. These results indicate that at least for standard lactations, the breed of sire of foetuses has no relevant consequences for estimations of breeding values.
Foetal sire effects The effects of the sire of foetus are, with one exception, always significant. The foetal-sire effect on milk production was calculated as the correlation between the record of the dam, corrected for the various factors included in the model, and the breeding value for the specific foetal effect on milk production TABLE2 Effect of the breed of the sire of foetus on a subsequent lactation yield (average of the 3 years) Breed of sire
Milk yield in kg (LS Constants) ~ Multiparous
Si 1/4RH 1/2RH 3/4 R H RH
Primiparous
100-day
305-day
100-day
305-day
-24 -11 - 6 3 36
-
-15 4 - 4 5 9
-6
1 2 4 3 10
1 2 2 1
~SE of the annual 100- and 305-day milk yields ranged from 3.2 to 8.8 kg and from 2.2 to 5.1 kg, respectively.
111 TABLE 3 Correlations between breeding value for the specific foetal effect on milk production of the sire of foetus and milk yield of the subsequent lactation of the dam (average of the 3 years) Parity
100-day milk yield 305-day milk yield
Multiparous
Primiparous
0.06 0.05
0.11 0.07
TABLE 4 Regression coefficients for milk yield of the dam on birth weight on her calf (kg milk kg-1 birth weight) 1 Year
1980 1981 1982
Multiparous
Primiparous
100 day
305 day
100 day
305 day
1.33"** 1.32"** 1.62"**
0.51" 0.46* 0.98***
0.19 NS 1.24"** 0.58 NS
0.03 NS 0.05 NS 0.29 NS
1NS = P > 0.05; * = P < 0.05; *** = P < 0.001.
of the sire of the foetus as presented by Skjervold and Fimland (1975) (Table 3 ). The correlation coefficients are lower in multiparous than in primiparous dams and correlations for 100-day milk yield are somewhat larger than those for the 305-day ones. These figures suggest that the sire of foetus accounts for a very small amount (1% and less) of the variation in the milk yield. These figures are in agreement with most studies summarized in Van Vleck and Johnson (1980). In separate analyses, least squares constants for sire of foetus effects were estimated within years and breed groups. The mean difference between the two extreme sire constants average 70 kg for the 100-day and 44 kg for the 305day milk yield in multiparous dams; these figures are 90 kg and 40 kg, respectively, for primiparous dams.
Birth weight The birth weight of the calf significantly affects the milk production of the dam only in multiparous cows (Table 4). This influence is more important for 100-day than for standard lactation yields. In primiparous cows, all but one of the regressions of milk production of the dam on birth weight of her calf are not significant. No explanation can be given as to why this one value is so extreme, the corresponding regression on the standard lactation is, however,
112
very small. These figures are all positive as in other studies too, but very much smaller (Thatcher et al., 1980). A possible reason why birth weight does not affect the milk yield in primiparous as much as in multiparous cows could be the lighter birth weight of the calves (40.6 versus 44.7 kg). In a preliminary analysis it could be shown that sex of calf had a significant effect on the 100-day milk yield only in multiparous dams and none in the other cases. Sex of calf has an indirect effect because weight of male calves is significantly larger than females.
Foetal effect on current lactation yields Breed of sire of foetus Breed of sire of foetus shows only a significant effect in multiparous cows, but the magnitude remains small (Table 5). The foetal effect is smaller on the penultimate 60-day milk yield than on the ultimate one. This can be explained by the younger age of the foetus and consequently also by a smaller placental volume. In contrast to the foetal effect on subsequent lactation it seems that the Red Holstein has an unfavourable effect on the end of the current lactation, whereas the Simmental shows a positive effect. Persistency at the end of lactation of cows inseminated with a RH bull is somewhat lower than with Simmental. Foetal-sire effects Foetal-sire effects were, with one exception, always significant (data not shown) and the magnitude was calculated as the coefficient of correlation between the genotype of the sire of the foetus and the milk production of the dam (Table 6). This genetic effect of the foetus on milk production seems to be the same in multiparous and primiparous cows and for all three traits. The figures for the ultimate 60-day milk yield are in good agreement with those estimated by Skjervold (1979) but the correlation coefficients for the penultimate 60day milk yield are larger. TABLE 5 Effect of the breed of the sire of foetus on current lactation in multiparous cows (averages of the LS constants over the 3 years) Performance
Breed Si
1/4 RH
3 Penultimate 60-day milk yield (kg) 6 15 6 Ultimate 60-day milk yield (kg) 0.035 0.006 Persistency (kg day- 1)
1/2 RH 1
-2 -0.014
3/4 RH
RH
-1
-10 -19 - 0.034
-1 0.007
113 TABLE 6 Average of the correlations between the breeding value for the specific foetal effect on milk production of the sire of foetus and milk yield at the end of the current lactation of the dam Performance
Multiparous
Primiparous
Penultimate 60-day milk yield (kg) Ultimate 60-day milk yield (kg) Persistency (kg day -1)
0.07 0.09 0.09
0.08 0.10 0.10
TABLE 7 Effect of birth-weight classes in multiparous dams (average of the 3 years) Performance
Ultimate 60-day milk yield (kg) Persistency (kgday -1)
Birth-weight classes (kg) 30
35
40
45
50
55
60
9 0.015
11 0.018
3 0.010
1 0.009
- 4 -0.003
- 12 - 0.033
- 8 -0.017
In separate analyses, the individual sire of foetus effects were calculated, as well as the difference between the two extreme sire constants within year and breed group. The average range is the same in both dam groups and amounts to 46.0 kg for the penultimate 60-day milk yield and 60.5 kg for the ultimate 60-day milk production.
Birth weight In preliminary analyses of variance where birth weight was considered as a continuous variable, this effect had no significant influence on the trait at end of the current lactation. The birth weight was then grouped in 7 classes (2832, 33-37..., 58-62 kg) and incorporated into the least squares model as a fixed effect. In primiparous cows, none of the traits of end of lactation are affected by the weight of foetus. This factor also has no effect upon the penultimate 60day milk yield of multiparous cows. Birth-weight classes have a significant effect on the ultimate 60-day milk yield and persistency at the end of lactation (Table 7 ). An explanation as to why the effect of the weight of foetus on milk production during the penultimate 60 days of lactation is not significant, whereas during the ultimate 60 days it is significant, is the exponential growth of the foetus. During the penultimate 60 days the weight of foetus increases only about 3.5 kg whereas in the ultimate 60 days this increases by about 12.5 kg and starts to compete with milk production.
114 CONCLUSION
The results of this study suggest that there is a significant effect of the sire of foetus on the subsequent lactation and on the end of the current lactation of the dam. The physiological explanation of foetal effects may be due to foetal binucleate cells migrating across the foetal-maternal boundary and delivering b P L to the maternal circulation (Duello et al., 1986). The 3 distinct bPL forms show differing activities, which could be due to genetic differences (Arima and Bremel, 1983). Furthermore, Guilbault et al. (1985a,b) were able to show that variation of breed of sire of foetus influenced hormone concentrations of both maternal (progesteron, 15-keto-13,14-dihydro-prostaglandin F2a) and conceptus (estrogen) origin during the preparturient period. Variations in circulating estrogens could contribute to significant variations in milk production of the dam. The correlations between the breeding value for the specific foetal effect on milk production of the sire of foetus and the milk yield of the dam are, however, small and range from 0.05 to 0.10. The breed of sire of foetus affects dam milk production in multiparous cows but only occasionally affects this in primiparous cows. The difference between the two parity groups could be due to the small breed effects and the large number of records in multiparous compared with primiparous cows. The foetal effect of the breed of sire of foetus seems to be somewhat smaller between Simmental and Red Holstein than between sires of foetus within breeds. Although the sire of the foetus has a significant effect, the genetic implications seem relatively unimportant in sire evaluation, since the largest difference between sire of foetus averages only 40 kg for the standard lactation in primiparous cows. The gain in accuracy, when the sire of foetuses is incorporated in the sire evaluation model does not outweigh the additional costs (labour for getting all sire of foetus information, computer, etc. ). The use of the birth weight of the calf as alternative to correct milk yield of the dam does not contribute very much either, because it does not affect the production of primiparous cows. Further, a reliable and systematic registration of birth weights could be hard to achieve in practice. It might be cautious not to select cows based only on the 100-day milk yield because the carry-over effect of the sire of foetus can bias the production record to some extent. ACKNOWLEDGEMENTS
The authors thank Dr. J. Crettenand of the Simmental Herdbook, J. Chavaz and R. Weber of the Swiss Association of AI for making the data available.
115 REFERENCES Adkinson, R.W., Wilcox, C.J. and Thatcher, W.W., 1977. Effects of sire of fetus upon subsequent production and days open of the dam. J. Dairy Sci., 60: 1964-1969. Anderson, R.R., 1975. Mammary gland growth in the hypophysectomized pregnant rat. Proc. Soc. Exp. Biol. Med., 148: 283. Arima, Y. and Bremel, R.D., 1983. Purification and characterization of bovine placental lactogen. Endocrinology, 113: 2186-2194. Bolander, Jr., F.F., Ulberg, L.C. and Fellows, R.E., 1976. Circulating placental lactogen levels in dairy and beef cattle. Endocrinology, 99: 1273-1278. Butler, W.R., Fullenkamp, S.M., Cappiello, L.A. and Handwerger, S., 1981. The relationship between breed and litter size in sheep and maternal serum concentrations of placental lactogen, estradiol and progesterone. J. Anim. Sci., 53: 1077-1081. Buttle, H.L. and Forsyth, I.A., 1976. Placental lactogen in the cow. J. Endocrinol., 68: 141-146. Buttle, H.L., Cowie, A.T., Jones, E.A. and Turvey, A., 1978. The contribution of placental hormones to the development of the mammary glands in goats. J. Endocrinol., 77: 59. Duello, T.M., Byatt, J.C. and Bremel, R.D., 1986. Immunohistochemical localisation of placental lactogen in binucleate cells of bovine placentomes. Endocrinology, 119: 1351-1355. Gaillard, C. and Chavaz, J., 1982. Genetic parameters for calving performance in Simmental cattle. Proc. 2nd World Congr. Genet. Appl. Livest. Prod., Madrid, 8: 189-194. Guilbault, L.A., Thatcher, W.W., Collier, R.J. and Wilcox, C.J., 1985a. Periparturient endocrine changes of conceptus and maternal units in Holstein heifers bearing genetically different conceptuses. J. Anim. Sci., 61: 1505-1515. Guilbault, L.A., Thatcher, W.W., Collier, R.J., Wilcox, C.J. and Drost, M., 1985b. Carry-over effects of periparturient endocrine changes on postpartum reproductive function of Holstein heifers bred to genetically different service sires. J. Anim. Sci., 61: 1516-1526. Harvey, W.R., 1987. Users guide for LSMLMW: Mixed model least-squares and maximum likelihood computer program, 10/1985. Revised January, 1987. Ohio State University, Columbus, Ohio 42210 (mimeo.). Hayden, T.J., Thomas, C.R. and Forsyth, I.A., 1979. Effect of number of young born (litter size) on milk yield of goats: role for placental lactogen. J. Dairy Sci., 62: 53-57. Hayden, T.J., Thomas, C.R., Smith, S.V. and Forsyth, I.A., 1980. Placental lactogen in the goat in relation to stage of gestation, number of fetuses, metabolites, progesterone and time of day. J. Endocrinol., 86: 279-290. Land, R.B. and Robinson, D.W., 1985. Genetics of reproduction in sheep. Butterworths, Lee, C.S. Gogolin-Ewens, K. and Brandon, M.R., 1986. Comparative studies on the distribution of binucleate cells in the placentae of the deer and cow using the monoclonal antibody, SBU3. J. Anat., 147: 163-179. More O'Ferrall, G.J., Cunningham, E.P. and Badi, A.M., 1985. Does breed of bull affect production from Friesian Cows? Farm Food Res., 16: 24-26. Reimers, T.J., Ullmann, M.B. and Hansel, W., 1985. Progesterone and prostanoid production by bovine binucleate trophoblastic cells. Biol. Reprod., 33: 1227-1236. Saner, R., 1987. Abkl~irungen tiber den Einfluss des Vaters des Foeten auf die Milchleistung der Mutter beim Schweizerischen Fleckvieh. Dissertation Universita't Bern. Schams, D., Rtisse, I., Schallenberger, E., Prokopp, S. and Chan, J.S.D., 1984. The role of steroid hormones, prolactin and placental lactogen on mammary gland development in ewes and heifers. J. Endocrinol., 102: 121-130. Schellenberg, C. and Friesen, H.G., 1982. The bioassay of bovine placental lactogen. Endocrinology, 111: 2125-2128. Schweizerischer Fleckviehzuchtverband, 1983. Ergebnisse der Milchleistungsprtifungen beim Simmentaler Fleckvieh in Kontrolljahr, 1982/83. Simmentaler Fleckvieh, 7: 40-65.
116 Skjervold, H., 1979. Effect of foetal genotype on maternal performance. Indian J. Anim. Genet. Breeding, 1: 23-29. Skjervold, H. and Fimland, E., 1975. Evidence for a possible influence of the fetus on the milk yield of the dam. Z. Tierz. Zuechtungsbiol., 92" 245-251. Steine, T.A., 1975. Einskfld-kontrollar of del-laktasjonar hos geit (Test day records and part lactations in goat). Sci. Rep. Agric. Univ. Norway, 54:(31 ): 1-25. Thatcher, W.W., Wilcox, C.J., Collier, R.J., Eley, D.S. and Head, H.H., 1980. Bovine conceptusmaternal interactions during the pre- and postpartum periods. J. Dairy Sci., 63: 1530-1540. Thompson, L.J. and Anderson, R.R., 1977. Effect of pregnancy on lactation in mice. J. Dairy Sci., 60: 126-128. Van Vleck, L.D., 1978. A genetic model involving fetal effects and traits of the dam. Biometrics, 34: 123-!27. Van Vleck, L.D. and Johnson, L.P., 1980. Genetic and economic implications of fetal effects on the dam. J. Dairy Sci., 63: 1483-1491. Wooding, F.B.P., 1983. Frequency and localization of binucleate cells in the placentomes of ruminants. Placenta, 4: 527-540. Wooding, F.B.P., 1984. Role of binucleate cell fusion at implantation in the sheep. Am. J. Anat., 170: 233-250. Wooding, F.B.P. and Wathes, D.C., 1980. Binucleate cell migration in the bovine plazentome. J. Reprod. Fertil., 59: 425-430. RESUME Saner, R. and Gaillard, C., 1988. Effet du p~re du foetus sur la production laiti~re maternelle de la lactation en cours et de la suivante. Livest. Prod. Sci., 20:107-117 (en anglais). L'influence du p~re du foetus et du poids du veau h la naissance sur la production laiti~re de la lactation en cours et de la suivante a ~t~ Studi~e dans la race tachet~e rouge du Simmental. L'~tude se base sur les productions laiti~res de 19 339 primipares et 53 942 multipares portant des foetus de 260 p~res diff~rents, comprenant 5 groupes raciques provenant du croisement Red Holstein × Simmental. La correlation entre le rendement laitier de la mbre (corrigd pour diff~rents facteurs) et le genotype du pbre du foetus a ~t~ le param~tre utilis~ pour ~valuer l'effet du foetus sur la production laiti~re. Ces correlations sont faibles aussi bien pour la lactation en cours que pour la suivante, elles varient entre 0.04 et 0.11. La production laiti~re des vaches multipares est influencde par la race du p~re du foetus. Chez les primipares cela n'est le cas qu'occasionellement. L'effet du poids de veau h la naissance est significatif mais faible et ne se manifeste que chez les multipares. Bien que le p~re du foetus ait un effet significatif sur la production laitibre de la m~re, les consdquences g~nStiques ne semblent pas importantes pour l'~valuation de la valeur d'$1evage des taureaux. En effet, la plus grande difference observ~e ne s'~lbve qu'~ 40 kg pour les lactations standards chez les primipares. Ces effets sont un peu plus importants pour le rendement laitier 100 jours (90 kg). KURZFASSUNG Saner, R. und Gaillard, C., 1988. Einfluss des Vaters des Foeten auf die laufende und folgende Laktationsleistung der Mutter. Livest. Prod. Sci., 20:107-117 (auf englisch). Der einflussdes Vaters des Foeten und des Geburtsgewichtes des Kalbes auf die laufende und folgendeLaktationsleistungvon Simmentalerkiihen wurde untersucht.Die Auswertungen stfitzen
117 sich auf Milchleistungen von 19 339 erstlaktierenden un 53 942 ~ilteren Kiihen, die Foeten von 260 Vatertieren mit unterscheidlichem Red Holstein-Anteiltrugen. Der foetale Vatereffekt wurde durch die Korrelation zwischen der M~lchleistung der Mutter, korrigiert fiir mehrere Einflussfaktoren, und dem Genotyp des Vaters des Foeten bestimmt. Diese Korrelationen waren sowohl ftir die laufende wie ftir die folgende Laktation klein und lagen zwischen 0.04 und 0.11. Die Leistung von ~ilteren Ktihen wurde durch die Rasse des Vaters des Foeten beeinflusst; dies war bei Erstlingsktihen nut zeitwiese der Fall. Das Geburtsgewicht des Kalbes hatte ausschliesslich bei ~lteren Kiihen einen signifikanten, abet nur geringen Effekt auf die Milchleistung. Obgleich der Vater des Foeten einen signifikanten Einfluss auf die Milchleistung der Mutter austibt, scheinen die genetischen Konsequenzen fiir die Zuchtwertschiitzung der Stiere unwesentlich zu sein, da bei Standardlaktationen von Erstlingskiihen der grSsste Unterschied zwischen V~iter der Foeten im Mittel nur 40 kg betr~igt. Die Unterschiede sind etwas geringer, wenn es sich um 100-Tage-Leistungen handelt (90 kg).