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Metabolic adaptation during pregnancy in winter-shorn sheep

Published online by Cambridge University Press:  27 March 2009

M. E. Symonds ,
M. J. Bryant  and
M. A. Lomax
M. J. Bryant
Affiliation:
Agriculture, University of Reading, Whiteknights, Reading RG6 2AJ
M. A. Lomax
Affiliation:
Departments of Physiology and Biochemistry
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Summary

The effects of winter shearing on ewe live weight, body condition score (BCS) and the concentrations of glucose, non-esterified fatty acids (NEFA), 3-hydroxybutyrate, growth hormone (GH), cortisol, insulin and the thyroid hormones in plasma plus that of oxygen and carbon dioxide in jugular vein blood and packed cell volume (PCV) were measured at weekly intervals over the final 7 weeks of pregnancy in two groups of multiple-bearing shorn and unshorn pregnant ewes.

Shorn ewes lost 47% more live weight than unshorn controls over the period from the day of being shorn to immediately after lambing. There was a significant decrease in BCS in both groups between 45 and 9 days before lambing. Three days after shearing the plasma NEFA concentration was higher in the shorn group but there were no other significant differences between shorn and unshorn groups in the plasma concentrations of NEFA, cortisol or insulin over the remaining 7 weeks of pregnancy. Both the PCV and concentration of carbon dioxide in blood were higher in shorn sheep throughout the final 6 weeks of pregnancy indicating they were making metabolic adaptations to long-term cold exposure. This response may have been mediated via an increase in thyroid hormone concentrations which were higher throughout the 7-week sampling period in shorn animals compared with unshorn controls. A decrease in ambient temperature was associated with a significant increase in the plasma concentration of GH and glucose in shorn animals. At 2 weeks before lambing there was a decrease in the plasma glucose concentration and an increase in 3-hydroxybutyrate concentration in the unshorn ewes, but these changes were not observed in the shorn animals. It is concluded that winter shearing of the pregnant ewe results in an increased loss of maternal body tissues and metabolic adaptations to long-term cold exposure without any of the changes associated with an increase in energy expenditure during the final third of pregnancy.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 111 , Issue 1 , August 1988 , pp. 137 - 145
Copyright
Copyright © Cambridge University Press 1988

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References

Agricultural Research Council (1980). The Nutrient Requirements of Ruminant Livestock. Slough: Commonwealth Agricultural Bureaux.Google Scholar
Aulie, A. A., Astrup, H. N., Nedkvitne, J. J. & Velle, W. (1971). Serum non-esterified fatty acids and glycerol as indicators of fat mobilization in pregnant sheep subjected to cold stress. Ada Velerinara Scandinavica 12, 496–503.CrossRefGoogle ScholarPubMed
Blom, A. K., Hove, K. & Nedkvitne, J. J. (1976). Plasma insulin and growth hormone concentrations in pregnant sheep. II. Post-absorptive levels in mid- and latepregnancy. Ada Endocrinologica 82, 553–560.Google Scholar
Christopherson, R. J., Thompson, J. R., Hammond, V. A. & Hills, G. A. (1978). Effects of thyroid status on plasma adrenaline and noradrenaline concentrations in sheep during acute and chronic cold exposure. Canadian Journal of Animal Science 56, 699–708.Google ScholarPubMed
Faulkner, A., Thomson, E. M., Bassett, J. M. & Thompson, G. E. (1980). Cold exposure and mammary glucose metabolism in the lactating goat. British Journal of Nutrition 43, 163–170.CrossRefGoogle ScholarPubMed
Geisler, P. A. & Jones, C. M. (1979). A model for the calculation of the energy requirements of the pregnant ewe. Animal Production 29, 339–355.Google Scholar
Graham, A. D., Christopherson, R. J. & Thompson, J. R. (1981). Endocrine and metabolic changes in sheep associated with acclimation to constant or intermittent cold exposure. Canadian Journal of Animal Science 61, 81–90.CrossRefGoogle Scholar
Graham, N. McC., Wainman, F. W., Blaxter, K. L. & Armstrong, D. G. (1958). Environmental temperature, energy metabolism and heat regulation in sheep. I. Energy metabolism in closely clipped sheep. Journal of Agricultural Science, Cambridge 52, 13–24.CrossRefGoogle Scholar
Hart, I. C., Blake, L. A., Chadwick, M. E., Payne, G. E. & Simmonds, A. D. (1984). The heterogeneity of bovine growth hormone. Biochemical Journal 218, 573–581.CrossRefGoogle ScholarPubMed
Hove, K. & Blom, A. K. (1976). Plasma insulin and growth hormone concentrations in pregnant sheep. I. Diurnal variations in mid- and late-pregnancy. Acta Endocrinologica 82, 544–552.Google ScholarPubMed
Humbel, R. E., Bosshard, H. R. & Zahn, H. (1972). Chemistry of insulin. In Handbook of Physiology, Vol. 1, Section 7 (ed. Freinkel, N. and Steiner, D. F.), pp. 111–132. Washington: American Physiological Society.Google Scholar
Kennedy, P. M., Young, B. A. & Christopherson, R. J. (1977). Studies on the relationship between thyroid function, cold acclimation and retention time of digest in sheep. Canadian Journal of Animal Science 45, 1084–1090.CrossRefGoogle ScholarPubMed
Ministry Of Agriculture Fisheries And Food (1976). Nutrient Allowances and Composition of Feedingstuffs for Ruminants. MAFF Publication LGR 21.Google Scholar
Ministry Of Agriculture Fisheries And Food (1982). Winter shearing of housed ewes. ADAS Report, 1981, pp. 27–28.Google Scholar
Mellor, D. J. & Matheson, I. C. (1979). Daily changes in the curved crown-rump length of individual fetuses during the last 60 days of pregnancy and effects of different levels of maternal nutrition. Quarterly Journal of Experimental Physiology 64, 119–131.CrossRefGoogle ScholarPubMed
Mellor, D. J. & Murray, L. (1982). Effects on the rate of increase in fetal girth of refeeding ewes after short periods of severe undernutrition during late pregnancy. Research in Veterinary Science 32, 377–382.CrossRefGoogle ScholarPubMed
Oddy, V. H., Gooden, J. M. & Annison, E. F. (1984). Partition of nutrients in Merino ewes. I. Contribution of skeletal muscle, the pregnant uterus and the lactating mammary gland to total energy expenditure. Australian Journal of Biological Sciences 38, 95–108.CrossRefGoogle Scholar
Olsen, J. D. & Trenkle, A. (1973). Exposure of cattle to controlled subzero temperature: growth hormone, glucose and free fatty acid concentrations in plasma. American Journal of Veterinary Research 34, 747–751.Google ScholarPubMed
Panaretto, B. A. & Vickery, M. R. (1970). The rates of plasma cortisol entry and clearance in sheep before and during their exposure to a cold, wet environment. Journal of Endocrinology 47, 273–285.CrossRefGoogle ScholarPubMed
Robinson, J. J., McDonald, I., McHattie, I. & Pennie, K. (1978). Studies on reproduction in prolific ewes. 4. Sequential changes in the maternal body during pregnancy. Journal of Agricultural Science, Cambridge 91, 291–304.CrossRefGoogle Scholar
Russell, A. J. F. (1984). Means of assessing the adequacy of nutrition of pregnant ewes. Livestock Production Science 11, 429–436.CrossRefGoogle Scholar
Russell, A. J. F., Armstrong, R. H. & White, I. R. (1985). Studies on the shearing of housed pregnant ewes. Animal Production 40, 47–53.Google Scholar
Rutter, W., Laird, T. R. & Broadbent, P. J. (1971). The effects of clipping pregnant ewes at housing and of feeding different basal diets. Animal Production 13, 329–336.Google Scholar
Rutter, W., Laird, T. R. & Broadbent, P. J. (1972). A note on the effects of clipping pregnant ewes at housing. Animal Production 14, 127–130.Google Scholar
Sasaki, Y. & Takahashi, H. (1980). Insulin secretion in sheep exposed to cold. Journal of Physiology 306, 127–130.CrossRefGoogle ScholarPubMed
Simpson, D. J., Greenwood, R. E. S., Ricketts, S. W., Rossdale, P. D., Sanderson, M. & Allen, W. R. (1982). Use of ultrasound echography for early diagnosis of single and twin pregnancy in the mare. Journal of Reproduction and Fertility, Supplement 32, 153–158.Google ScholarPubMed
Symonds, M. E. (1986). Energy metabolism in the shorn and unshorn pregnant ewe. Ph. D. thesis, University of Reading.Google Scholar
Symonds, M. E., Bryant, M. J. & Lomax, M. A. (1985). The effect of shearing on plasma glucose, free fatty acid, growth hormone and insulin concentrations in the pregnant ewe. Proceedings of the Nutrition Society 44, 136 (Abstract).Google Scholar
Symonds, M. E., Bryant, M. J. & Lomax, M. A. (1986). The effect of shearing on the energy metabolism of the pregnant ewe. British Journal of Nutrition 56, 635–643.CrossRefGoogle ScholarPubMed
Thompson, G. E., Gardner, J. W. & Bell, A. W. (1976). The oxygen consumption, fatty acid and glycerol uptake of the liver in fed and fasted sheep during cold exposure. Quarterly Journal of Experimental Physiology 60, 107–121.CrossRefGoogle Scholar
Trenkel, A. (1981). Endocrine regulation of energy metabolism in ruminants. Federation Proceedings 40, 2536–2541.Google Scholar
Vernon, R. G., Clegg, R. A. & Flint, D. J. (1981). Metabolism of sheep adipose during pregnancy and lactation. Biochemical Journal 200, 307–314.CrossRefGoogle ScholarPubMed
Webster, A. J. F., Hicks, A. M. & Hays, F. L. (1969). Cold climate and cold temperature changes in the heat production and thermal insulation of sheep. Canadian Journal of Physiology and Pharmacology 47, 553–562.CrossRefGoogle ScholarPubMed
Westra, R. & Christopherson, R. J. (1976). Effects of cold on digestibility, retention time of digesta, reticulum motility and thyroid hormones in sheep. Canadian Journal of Animal Science 56, 699–708.CrossRefGoogle Scholar
Wilhelmi, A. E. (1972). Chemistry of growth hormone. In Handbook of Physiology, Vol. 4, Section 7 (ed. Knobil, E. and Sawyer, W. H.), pp. 59–78. Washington: American Physiological Society.Google Scholar
Williamson, D. H. (1981). Mechanisms for the regulation of ketogenesis. Proceedings of the Nutrition Society 40, 93–98.CrossRefGoogle ScholarPubMed