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A study of the growth of sheep to maturity

Published online by Cambridge University Press:  27 March 2009

K. L. Blaxter ,
V. R. Fowler  and
J. C. Gill
K. L. Blaxter
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen, AB1 9SB
V. R. Fowler
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen, AB1 9SB
J. C. Gill
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen, AB1 9SB
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Summary

Two groups of weaned sheep weighing about 30 kg, one born in March and the other in September, were each divided into two and given ad libitum one of two pelleted diets, ruminant diet A or ruminant diet AA6. The March-born sheep commenced experiment in July and those born in September in January. The experiment continued for 4½ years. At intervals sheep were killed and the fat protein and ash contents of their digesta-free bodies determined.

The voluntary intake of feed showed a seasonal periodicity with minima in the winter and maxima in summer. The amplitude was 30% in the 1st year and in subsequent years averaged 13%. Those given the higher quality diet (AA6) consumed slightly less than those given the poorer one.

Mean daily feed intake averaged over 6-month periods from January to July and July to January was invariant with age during 4 years of observation. In this time the sheep increased in weight from about 30 kg to about 130 kg. There were, however, considerable differences between individual sheep in the amount of feed they habitually consumed.

The body weight of the sheep increased and eventually plateaued. The asymptotic weight defined as A in the equation W = A–Be–kt, where W is weight at time t and B and k are constants, was related to the mean daily feed intake averaged over 6 months; mean daily feed intake measured over 6 months was proportional to a fractional power of body weight indistinguishable from 0·75, the interspecies power to which metabolism is proportional. Growth of wool during successive 6-month periods did not vary with age of animal but differed significantly between animals.

Fasting metabolism of the sheep was 316 kJ/kg W0·75 for wethers and 336 kJ for rams.

Analysis of the bodily composition data showed that over a range of digesta-free body weight from 46 to 130 kg it was not possible, on statistical grounds, to distinguish between linear relationships between body weight and its fat, protein, ash and water content, and allometric ones. The linear relationships had marginally smaller residual standard deviations and the regression coefficients show that the gain of the empty body in these sheep consisted of 68% lipid, 8% protein, 1% ash and 24% water. The lipid in the carcass accounted for 88% of the total lipid gain and half the accretion of protein and ash was in the carcass. These results confirm those of Searle, Graham & O'Callaghan (1972) based on tritium dilution which showed that post-puberal growth in sheep is of constant composition.

The results of the metabolic studies are shown to be consistent with the growth studies.

Growth to maturity, as affected by different hypotheses related to the determinants of maintenance energy expenditure and the regulation of appetite, was examined algebraically. It is shown that mature weight is the rate of feed intake divided by the rate of maintenance metabolism per unit weight, and for defined feeding systems the rate constant for the approach to mature weight is the rate of maintenance metabolism divided by the feed equivalent of unit gain.

The implications of the results in terms of the measurement and prediction of feed intake and the use of metabolic body size as a scaling factor in comparative and genetic studies of growth are briefly discussed.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 98 , Issue 2 , April 1982 , pp. 405 - 420
Copyright
Copyright © Cambridge University Press 1982

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References

REFERENCES

Agricultural Research Council (1980). The Nutrient Requirements of Farm Livestock and Ruminants, 2nd edn.Farnham Royal: Commonwealth Agricultural Bureaux.Google Scholar
Atkinson, T., Fowler, V. R., Garton, G. A. & Lough, A. K. (1972). A rapid method for the accurate determination of lipid in animal tissue. Analyst, London 97, 562–568.CrossRefGoogle Scholar
Baile, C. A. & Forbes, J. M. (1974). Control of feed intake and regulation of energy balance in ruminants. Physiological Reviews 54, 160–214.CrossRefGoogle ScholarPubMed
Bailey, C. B., Kitts, W. D. & Wood, A. J. (1960). Changes in the gross chemical composition of the mouse during growth in relation to the assessment of physiological age. Canadian Journal of Animal Science 40, 143–155.CrossRefGoogle Scholar
Blaxter, K. L. (1968). The effect of dietary energy supply on growth. In Growth and Development of Mammals (ed. Lodge, G. A. and Lamming, G. E.), pp. 329–344. London: Butterworths.Google Scholar
Blaxter, K. L. & Boyne, A. W. (1978). The estimation of the nutritive value of feeds as energy sources for ruminants and the derivation of feeding systems. Journal of Agricultural Science, Cambridge 90, 47–68.CrossRefGoogle Scholar
Blaxter, K. L., Clapperton, J. L. & Wainman, F. W. (1966). Utilization of the energy and protein of the same diet by cattle of different ages. Journal of Agricultural Science, Cambridge 67, 67–75.CrossRefGoogle Scholar
Blaxter, K. L., Wainman, F. W. & Wilson, R. S. (1961). The regulation of food intake by sheep. Animal Production 3, 51–61.Google Scholar
Boalch, D. H. (1958). Prints and Paintings of British Farm Livestock 1780–1910 Harpenden: Rothamsted Experimental Station Library.Google Scholar
Brody, S. (1945). Bioenergetics and Growth. New York: Reinhold.Google Scholar
Clapperton, J. L. & Blaxter, K. L. (1965). Absence of long-term adaptation in the energy metabolism of sheep on constant feed. Proceedings of the Nutrition Society 24, xxxiii.Google Scholar
Davidson, J., Mathieson, J. & Boyne, A. W. (1970). The use of automation in determining nitrogen by the Kjeldahl method, with final calculations by computer. Analyst, London 95, 181–193.CrossRefGoogle ScholarPubMed
Department of Agriculture and Fisheries for Scotland (1976). Feedingstuffs Evaluation Unit First Report 1975. Edinburgh: H.M.S.O.Google Scholar
El Shahat, A., Jones, R., Forbes, J. M. & Boaz, T. G. (1974). The effect of day length on the growth of lambs at two levels of feeding. Proceedings of the Nutrition Society 33, 83A–84A.Google ScholarPubMed
Forbes, J. M. (1977). Interrelationships between physical and metabolic control of voluntary food intake in fattening, pregnant and lactating mature sheep: a model. Animal Production 24, 91–101.Google Scholar
Forbes, J. M. (1980). A model of the short-term control of feeding in the ruminant: effects of changing animal or feed characteristics. Appetite 1, 21–41.CrossRefGoogle Scholar
Forbes, J. M., Driver, P. M., el Shahat, A. A., Boaz, T. G. & Scanes, C. G. (1975). The effect of daylength and level of feeding on serum prolactin in growing lambs. Journal of Endocrinology 64, 549–554.CrossRefGoogle ScholarPubMed
Gordon, J. G. (1964). Effect of time of year on the roughage intake of housed sheep. Nature, London 204, 798–799.CrossRefGoogle ScholarPubMed
Graham, N. McC. (1969). The influence of body weight (fatness) on the energetic efficiency of, adult sheep. Australian Journal of Agricultural Research 20, 375–385.Google Scholar
Graham, N. McC. & Searle, T. W. (1972). Growth in sheep. II. Efficiency of energy and nitrogen utilization from birth to 2 years. Journal of Agricultural Science, Cambridge 79, 383–389.CrossRefGoogle Scholar
Greenhalgh, J. F. D. & McDonald, I. (1978). The metabolizable energy system in practice. Predicting feed intake. Animal Production 26, 350.Google Scholar
Gunther, B. & Guerra, E. (1955). Biological similarities. Acta Physiologica Latinoamericana 5, 169–178.Google ScholarPubMed
Haecker, T. L. (1920). Investigations in beef production. Bulletin, Minnesota Agricultural Experimental Station No. 193.Google Scholar
Holmes, W. (1973). Size of animal in relation to productivity with special reference to the ruminant: nutritional aspects. Proceedings of the British Society of Animal Production New Series 2, 27–34.CrossRefGoogle Scholar
Kay, R. N. B. (1979). Seasonal changes of appetite in deer and sheep. Agricultural Research Council Research Review 5, 13–15.Google Scholar
Kay, R. N. B. & Ryder, M. L. (1978). Coat growth in red deer (Cervus elaphus) exposed to a day-length cycle of six months duration. Journal of Zoology, London 185, 505–510.CrossRefGoogle Scholar
Oscai, L. B. & McGarr, J. A. (1978). Evidence that the amount of food consumed in early life fixes appetite in the rat. American Journal of Physiology R141–144.Google ScholarPubMed
Peters, R. R., Chapin, L. T., Leining, K. B. & Tucker, H. A. (1978). Supplemental lighting stimulates growth and lactation in cattle. Science 199, 911–912.CrossRefGoogle ScholarPubMed
Robinson, J. J. (1974). Intensifying ewe productivity. Proceedings of the British Society of Animal Production 3, 31–40.Google Scholar
Searle, T. W. (1970). Body composition in lambs and young sheep and its prediction in vivo from tritiated water space and body weight. Journal of Agricultural Science, Cambridge 74, 357–362.CrossRefGoogle Scholar
Searle, T. W., Graham, N. McC. & O'callaghan, M. (1972). Growth in sheep. I. The chemical composition of the body. Journal of Agricultural Science, Cambridge 79, 371–382.CrossRefGoogle Scholar
Sheng, H.-P. & Huggins, R. A. (1971). Growth of the beagle: changes in chemical composition. Growth 35, 369–370.Google ScholarPubMed
Simpson, A. M. (1976). Energy metabolism and seasonal cycles of captive red deer. Ph.D. thesis, University of Aberdeen.Google Scholar
Tarttellin, M. F. (1968). Cyclical variations in food and water intakes in ewes. Journal of Physiology, London 195, 29P.Google Scholar
Taylor, St C. S. (1965). A relation between mature weight and time taken to mature in mammals. Animal Production 7, 203–220.Google Scholar
Taylor, St C. S. (1968). Time taken to mature in relation to mature weight for sexes, strains and species of domesticated mammals and birds. Animal Production 10, 157–169.Google Scholar
Taylor, St C. S. (1970). Models of maintenance requirement. In The Use of Models in Agricultural and Biological Research (ed. Jones, J. G. W.), pp. 107–117. Hurley: Grassland Research Institute.Google Scholar
Taylor, St C. S. (1980 a). Genetic size-scaling rules in animal growth. Animal Production 30, 161–165.Google Scholar
Taylor, St C. S. (1980 b). Genetically standardized growth equations. Animal Production 30, 167–175.Google 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, 311–314.CrossRefGoogle Scholar
Wainman, F. W., Dewey, P. J. S. & Boyne, A. W. (1979). Feedingstuffs Evaluation Unit Second Report. Edinburgh: H.M.S.O.Google Scholar
Wainman, F. W., Smith, J. S. & Dewey, P. J. S. (1974). The nutritive value for sheep of ruminant Diet AA6, a complete cobbed diet containing 30% barley straw. Journal of Agricultural Science, Cambridge 84, 109–111.CrossRefGoogle Scholar
Wood, A. J., Cowan, I. McT. & Nordan, H. C. (1962). Periodicity of growth in ungulates as shown by deer of the genus Odocoileus. Canadian Journal of Zoology 40, 593–603.CrossRefGoogle Scholar
Youalt, W. (1864). Cattle, their Breeds, Management and Diseases. London: Edward Law.Google Scholar