Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-24T22:33:27.317Z Has data issue: false hasContentIssue false

Studies on reproduction in prolific ewes

6. The efficiency pf energy utilization for conceptus growth

Published online by Cambridge University Press:  27 March 2009

J. J. Robinson
Affiliation:
The Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
I. McDonald
Affiliation:
The Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
C. Fraser
Affiliation:
The Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
J. G. Gordon
Affiliation:
The Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB

Summary

Estimates of the energy contents of the foetuses, placentae, foetal fluids, empty uteri and maternal empty bodies at 88 and at 144 days of pregnancy were obtained from a comparative slaughter experiment on Finnish Landrace × Dorset Horn ewes. Over this period the mean daily intakes of metabolizable energy (ME) for ewes with twin, triplet or quadruplet foetuses were 11·2, 12·0 and 12·2 MJ respectively (low plane of feeding) or 14·4, 15·2 and 15·3 MJ (high plane of feeding), total numbers of ewes being 15, 23 and 7 respectively. The diet contained 8·2 MJ of ME and 153 g crude protein per kg dry matter. All six categories of ewe lost energy from maternal empty-body tissues between 88 and 144 days at mean daily rates of 2·7, 4·1 and 4·9 MJ (low plane) and 1·4, 2·7 and 3·6 MJ (high plane), according to litter size. Rates of energy deposition in the gravid uterus were 0·72, 0·93 and 1·07 MJ/day respectively, and were not affected by plane of nutrition. Estimates of heat production from these balance data were confirmed by direct measurements made on about half of the ewes.

Estimates of the gross efficiency of utilization for foetal growth of the combined energy from maternal tissue and from ME intake, after allowing for maternal main–tenance, were similar for each litter size but were 0·14 and 0·11 on the low and high planes of feeding respectively. Consideration of these together with other published observations suggested that efficiency of utilization of ME in pregnancy increases linearly with the ME concentration of the diet and at concentrations below 10 MJ/kg dry matter is less than the efficiency of utilization of energy derived from maternal tissue loss.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1980

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agricultubal Research Council (1980). The Nutrient Requirements of Farm Livestock. No. 2. Ruminants, 2nd ed.London: Agricultural Research Council.Google Scholar
Battaglia, F. C. & Meschia, G. (1978). Principal substrates of fetal metabolism. Physiological Reviews 58, 499527.CrossRefGoogle ScholarPubMed
Blaxter, K. L. (1974). Metabolisable energy and feeding systems for ruminants. In Proceedings 7th Nutrition Conference for Feed Manufacturers (ed. Swan, H. and Lewis, D.), pp. 325. London: Butter-worths.CrossRefGoogle Scholar
Bkockway, J. M., McDonald, J. D. & Pullar, J. D. (1963). The energy cost of reproduction in sheep. Journal of Physiology 167, 318327.CrossRefGoogle Scholar
Girard, J., Pintado, E. & Ferre, P. (1979). Fuel metabolism in the mammalian fotus. Annales de Biologie Animale, Biochimie, Biophysique 19, 1 B, 181197.CrossRefGoogle Scholar
Graham, N. McC. (1964). Energy exchanges of pregnant and lactating ewes. Australian Journal of Agricultural Research 15, 127141.Google Scholar
Heaney, D. P. & Lodge, G. A. (1975). Body composition and energy metabolism during late pregnancy in the ad libitum fed ewe. Canadian Journal of Animal Science 55, 545555.CrossRefGoogle Scholar
Langlands, J. P. & Sutherland, H. A. M. (1968). An estimate of the nutrients utilized for pregnancy by Merino sheep. British Journal of Nutrition 22, 217227.CrossRefGoogle ScholarPubMed
Lodge, G. A. & Heaney, D. P. (1970). Energy cost of pregnancy in the ewe. In Energy Metabolism of Farm Animals (ed. Schürch, A. and Wenk, C.), pp. 109111. Zürich: Juris Druck. EAAP Publication No. 13.Google Scholar
Lodge, G. A. & Heaney, D. P. (1973). Energy cost of pregnancy in single and twin–bearing ewes. Canadian Journal of Animal Science 53, 479489.CrossRefGoogle Scholar
McDonald, I., Robinson, J. J., Fraser, C. & Smart, R. I. (1979). Studies on reproduction in prolific ewes. 5. The accretion of nutrients in the foetuses and adnexa. Journal of Agricultural Science, Cambridge 92, 591603.CrossRefGoogle Scholar
Pullar, J. D. (1969). Methods of Calorimetry (A) Direct. In Nutrition of Animals of Agricultural Importance. Part 1. The Science of Nutrition of Farm Livestock (ed. SirCuthbertson, David), pp. 471490. Oxford: Pergamon Press. (International Encyclopaedia of Food and Nutrition, vol. 17.)Google Scholar
Rattray, P. V., Garrett, W. N., East, N. E. & Hinman, N. (1973). Net energy requirements of ewe lambs for maintenance, gain and pregnancy and net energy values of feedstuffs for lambs. Journal of Animal Science 37, 853857.CrossRefGoogle Scholar
Rattray, P. V., Garrett, W. N., East, N. E. & Hinman, N. (1974). Efficiency of utilization of meta-bolizable energy during pregnancy and the energy requirements for pregnancy in sheep. Journal of Animal Science 38, 383393.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, 291304.CrossRefGoogle Scholar
Sykes, A. R. & Field, A. C. (1972). Effects of dietary deficiencies of energy, protein and calcium on the pregnant ewe. III. Some observations on the use of biochemical parameters in controlling energy under-nutrition during pregnancy and on the efficiency of utilization of energy and protein for foetal growth. Journal of Agricultural Science, Cambridge 78, 127133.CrossRefGoogle Scholar
Wainman, F. W., Blaxter, K. L. & Pullar, J. D. (1970). The nutritive value for ruminants of a complete processed diet based on barley straw. Journal of Agricultural Science, Cambridge 74, 311314.CrossRefGoogle Scholar