Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-25T05:12:23.103Z Has data issue: false hasContentIssue false

Growth in sheep. II. Efficiency of energy and nitrogen utilization from birth to 2 years

Published online by Cambridge University Press:  27 March 2009

N. McC. Graham
Affiliation:
C.S.I.R.O., Division of Animal Physiology, Ian Clunies Boss Animal Research Laboratory, Prospect, N.S.W., Australia*
T. W. Searle
Affiliation:
C.S.I.R.O., Division of Animal Physiology, Ian Clunies Boss Animal Research Laboratory, Prospect, N.S.W., Australia*

Summary

Thirty sheep were pen-fed from age 2 days to nearly 2 years. Fifteen were fed ad libitum and the others were restricted to half that rate, age for age; daily food intakes were recorded. Sequential estimates of body composition were made on each sheep so that protein and energy gains could be obtained for specified age ranges.

In the sheep fed ad libitum, food intake increased several fold in the first few months of life but was relatively constant from 4 months despite large increases in body weight. Thus intake per kg¾ declined progressively as the sheep grew.

The data for the well fed and restricted groups were combined within each age range and linear regression was used to relate body growth (protein and energy) to food intake, variates being expressed as multiples of body weight (kg¾). Energy gain was zero when intake was 250–590 kJ metabolizable energy/day kg¾, depending on age. Wool growth per unit food intake was constant for each sheep throughout the experiment but was twice as great in some sheep as in others and was higher in the restricted group.

Efficiency of energy and protein utilization declined at weaning but otherwise did not vary much with stage of growth. Approximately 40% of energy storage was in protein during milk feeding; after weaning, the fraction declined from 25 to 10% (30 to 20% including wool protein) as the sheep grew.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1972

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

REFERENCES

Alexander, G. (1962). Energy metabolism in the starved new-born lamb. Auat. J. agric. Res. 13,144–64.Google Scholar
Armstrong, D. G., Blaxter, K. L. & Graham, N. McC. (1957). Utilization of the end-products of ruminant digestion. Anim. Prod. 1, 315.Google Scholar
Armstrong, D. G., Blaxter, K. L., Clapperton, J. L., Graham, N. McC. & Wainman, F. W. (1960). Heat production and heat emission of two breeds of sheep. J. agric. Sci., Camb. 55, 395401.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. J. agric. Sci., Camb. 67, 6775.CrossRefGoogle Scholar
Blaxter, K. L. & Graham, N. McC. (1955). Plane of nutrition and starch equivalents. J. agric. Sci., Camb. 46, 292306.CrossRefGoogle Scholar
Blaxter, K. L. & Wainman, F. W. (1964). Utilization of the energy of different rations by sheep and cattle for maintenance and for fattening. J. agric. Sci., Camb. 63, 113128.CrossRefGoogle Scholar
Brouwer, E. (1965). Report of sub-committee on constants and factors. Publ. Eur. Ass. Anim. Prod. 11, 441–3.Google Scholar
Faichney, G. J. & Weston, R. H. (1971). Digestion by ruminant lambs of a diet containing formaldehydetreated casein. Aust. J. agric. Res. 22, 461–8.CrossRefGoogle Scholar
Ferguson, K. A. (1962). Relation between the responses of wool growth and body weight to changes in food intake. Aust. J. biol. Sci. 15, 720–31.Google Scholar
Graham, N. McC. & Searle, T. W. (1972). Balances of energy and matter in growing sheep at several ages, body weights and planes of nutrition. Aust. J. agric. Res. 23, 97108.CrossRefGoogle Scholar
Graham, N. McC, Wainman, F. W., Blaxter, K. L. & Armstrong, D. G. (1959). Environmental temperature, energy metabolism and heat regulation in sheep. I. Energy metabolism in closely clipped sheep. J. agric. Sci., Camb. 52, 1324.Google Scholar
Jordan, J. W. & Brown, W. O. (1970). Retention of energy and protein in the baby pig fed on cow's milk. Publ. Eur. Ass. Anim. Prod. 13, 161–4.Google Scholar
Milford, R. & Minson, D. J. (1965). The energy value of ryegrass and cocksfoot assessed by a slaughter technique with lambs. Br. J. Nutr. 19, 373–82.CrossRefGoogle ScholarPubMed
Reardon, T. F. (1969). Relative precision of the tritiated water and slaughter techniques for estimating energy retention in grazing sheep. Anim. Prod. 11, 453460.Google Scholar
Ritzman, F. G. & Colovos, N. F. (1943). Utilization of energy and protein by growing calves. Tech. Bull. N.H. agric. Exp. Stn. no. 80.Google Scholar
Searle, T. W. (1970 a). Body composition in lambs and young sheep and its prediction in vivo from tritiated water space and body weight. J. agric. Sci., Camb. 74, 357–62.Google Scholar
Searle, T. W. (1970 b). Prediction of body composition of sheep from tritiated water space and body weight – tests of published equations. J. agric. Sci., Camb. 75, 497500.Google Scholar
Searle, T. W., Graham, N. McC. & O'Callaghan, M. (1972). Growth in sheep. I. The chemical composition of the body. J. agric. Sci., Camb. 79, 371–82.Google Scholar
Thomson, D. J. (1965). Energy retention in lambs as measured by the comparative slaughter technique. Publ. Eur. Ass. Anim. Prod. 11, 319–26.Google Scholar
Walker, D. M. & Norton, B. W. (1970). The utilization of energy by the milk-fed lamb. Publ. Eur. Ass. Anim. Prod. 13, 125–28.Google Scholar
Wardrop, I. D. & Coombe, J. B. (1961). The development of rumen function in the lamb. Aust. J. agric. Res. 12, 661–80.Google Scholar
Weston, R. H. (1970). Voluntary consumption of low quality roughage by sheep during cold exposure. Aust. J. Exp. Agric. Anim. Husb. 10, 679–84.CrossRefGoogle Scholar
Weston, R. H. & Hogan, J. P. (1971). The digestion of pasture plants by sheep. I. Studies with subterranean and berseem clovers. Aust. J. agric. Res. 22, 139–57.CrossRefGoogle Scholar