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Low nutrition of ewes in early pregnancy and the residual effect on the offspring

Published online by Cambridge University Press:  27 March 2009

R. A. Parr
Affiliation:
Victorian Department of Agriculture and Rural Affairs, Animal Research Institute, Werribee, Victoria, Australia3030
A. H. Williams
Affiliation:
Victorian Department of Agriculture and Rural Affairs, Animal Research Institute, Werribee, Victoria, Australia3030
I. P. Campbell
Affiliation:
Victorian Department of Agriculture and Rural Affairs, Animal Research Institute, Werribee, Victoria, Australia3030
G. F. Witcombe
Affiliation:
Victorian Department of Agriculture and Rural Affairs, Animal Research Institute, Werribee, Victoria, Australia3030
A. M. Roberts
Affiliation:
Victorian Department of Agriculture and Rural Affairs, Animal Research Institute, Werribee, Victoria, Australia3030

Summary

Mature Merino ewes (n = 500) were allotted at random to embryo removal (day 35; day 0 = day of oestrus detection), foetal removal (day 90) or lambing groups. These groups were further randomly divided into four single-sire mating groups. From day 1 until day 35 ewes were individually penned and fed either 50 or 150% of a maintenance ration (0·5 M or 1·5 M respectively). At day 35 single embryos were removed from anaesthetized ewes in the embryo removal group and all other ewes were endoscoped to confirm pregnancy. These ewes were then returned to pasture. Plasma samples were taken from all ewes on days 2, 4, 16, 23, 30 and 35 for analysis of glucose concentration. At day 90, ewes allotted to the foetal removal group were anaesthetized and plasma samples were obtained from the ewe's jugular vein and the umbilical arteryand vein. Ewes were then hysterectomized and the foetus was weighed and measured. Functional cotyledons were dissected from the uterus and chorio-allantois and all tissues were weighed. The remaining ewes (lambing group) were supervised at lambing and lambs were identified, weighed and measured.

Live-weight changes from weaning and wool production and quality were measured in ewe and ram lambs at their first shearing (11 months of age). Ovulation rates in the first two oestrous seasons of the ewes and wool production at their second shearing (2 years of age) were also measured.

During the 35-day treatment period, mean live-weight changes of ewes were –4·9 and + 1·8 kg in the 0·5 M and 1·5 M groups respectively. Pregnancy rates were similar in both groups but embryos from 0·5 M ewes weighed less than those from 1·5 M ewes (1·7 ± 0·04 ν. 1·9 ± 0·05 g; P < 0·005). Foetuses taken at 90 days from 0·5 M ewes were smaller than those from 1·5 M ewes but these differences reached significance (P < 0·025) only in the measurement of chin–crown length (8·0 ± 0·09 ν. 7·6 ± 0·11 cm). Correlations between foetal weight and total cotyledon weight, chorio-allantoic weight and empty uterine weight were all significant. Plasma glucose concentrations of ewes in the 0·5 M group were significantly (P < 0·001) reduced by day 9. Differences between the two nutrition groups in maternal and umbilical plasma glucose concentrations at day 90 were not significant, though foetuses from 0·5 M and 1·5 M ewes removed a mean of 30 and 11% respectively of available glucose from the umbilical vein. Differences in live weight between 1·5 M and 0·5 M animals at weaning and in the post-weaning period were not significant (P > 0·05). Wool production and woolquality were similar for both groups. Spontaneous ovulation rates measured on four occasions during the postpubertal oestrous season and on three occasions the following year were not significant (P > 0·05). Treatment with pregnant mare's serum gonadotrophin (PMSG) increased ovulation rates in the ewes of both groups; however, the differences failed to reach significance (P > 0·05); mean (± S.e.) ovulations per ewe were 4·8 ± 0·61 ν. 4·6 ± 0·60 for 1·5 M and 0·5 M group ewes respectively.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1986

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References

REFERENCES

Bennett, D., Axelsen, A. & Chapman, H. W. (1964). The effect of nutritional restriction during early pregnancy on numbers of lambs born. Proceedings of the Australian Society of Animal Production 5, 7071.Google Scholar
Clark, C. F. S. & Speedy, A. W. (1980). The effects of pre-mating and early-pregnancy nutrition on foetal growth and body reserves in Scottish half bred ewes. Animal Production 30, 485.Google Scholar
Edey, T. N. (1968). Body weight and ovulation rate in sheep. Proceedings of the Australian Society of Animal Production 7, 188190.Google Scholar
Edey, T. N. (1970). Nutritional stress and pre-implantation embryonic mortality in Merino sheep, 1967. Journal of Agricultural Science, Cambridge 74, 193198.CrossRefGoogle Scholar
Edey, T. N. (1976). Nutrition and embryo survival in the ewe. Proceedings of the New Zealand Society of Animal Production 36, 231239.Google Scholar
Ellington, S. K. L. (1980). In vivo and in vitro studies on the effects of maternal fasting during embryonic organogenesis in the rat. Journal of Reproduction and Fertility 60, 383388.CrossRefGoogle ScholarPubMed
Everitt, G. C. (1964). Maternal undernutrition and retarded foetal development in Merino sheep. Nature 143a, 13411342.CrossRefGoogle Scholar
Green, W. W. & Winters, L. M. (1945). Prenatal development of the sheep. Technical Bulletin, Minnesota Agricultural Experiment Station 169, 136.Google Scholar
Hodgson, J. C., Mellor, D. J. & Field, A. C. (1979). Fetal metabolism. In Protein Metabolism in the Ruminant (ed. Buttery, P. J.), p. 61. London: Agricultural Research Council.Google Scholar
Killeen, I. D. (1974). Effects of liveweight of Border Leicester × Merino ewes and breed of ram on fertilization in flock-mated sheep. Journal of Reproduction and Fertility 36, 464465.CrossRefGoogle Scholar
Mauleon, P. (1976). Migratory phase of germ cells and sexual differentiation of the gonad in sheep embryo. Annales de Biologie Animale Biochimie Biophysigue 16 (2), 159.CrossRefGoogle Scholar
Morriss, F. H., Rosenfeld, C. R., Crandell, S. S. & Adcock, E. W. (1980). Effects of fasting on uterine blood flow and substrate uptake in sheep. Journal of Nutrition 110 (12), 24332443.CrossRefGoogle ScholarPubMed
Parr, R. A., Cumming, I. A. & Clarke, I. J. (1982). Effects of maternal nutrition and plasma progesterone concentrations on survival and growth of the sheep embryo in early gestation. Journal of Agricultural Science, Cambridge 98, 3946.CrossRefGoogle Scholar
Parr, R. A. & Williams, A. H. (1982). Nutrition of the ewe and embryo growth during early pregnancy. Australian Journal of Biological Science 35, 271276.CrossRefGoogle ScholarPubMed
Radford, H. M., Watson, R. H. & Wood, G. F. (1960). A crayon and associated harness for detection of mating under field conditions. Australian Veterinary Journal 36, 5766.CrossRefGoogle Scholar
Roberts, E. M. (1968). Endoscopy of the reproductive tract of the ewe. Proceedings of the Australian Society of Animal Production 7, 192194.Google Scholar
Trinder, P. (1969). Determination of glucose in blood using glucose oxidase with an alternative oxygen acceptor. Annals of Clinical Biochemistry 6, 2427.CrossRefGoogle Scholar
White, D. H., Rizzoli, D. J. & Cumming, I. A. (1981). Embryo survival in relation to number and site of ovulations in the ewe. Australian Journal of Experimental Agriculture and Animal Husbandry 21, 3238.CrossRefGoogle Scholar
Wilson, J. B. (1976). Teddybear Statistical Programme. Technical Report, 2nd ed.Dunedin, N.Z.: Otago University.Google Scholar