Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-25T06:03:25.908Z Has data issue: false hasContentIssue false

Seasonal changes in the composition and mineral content of the body of hill ewes

Published online by Cambridge University Press:  27 March 2009

A. C. Field
Affiliation:
Moredun Research Institute, Gilmerton, Edinburgh
N. F. Suttle
Affiliation:
Moredun Research Institute, Gilmerton, Edinburgh
R. G. Gunn
Affiliation:
Hill Farming Research Organization, Edinburgh

Summary

Groups of ewes kept under hill conditions were killed at intervals during October to July 1965–66. Supplementary feed was given between February and May. The carcasses were divided into soft tissue, uterus and its contents and skeletal fractions. Each fraction was dissolved in HNO3 and its fat and mineral content measured. The sheep were heavier in November and lighter in May during lactation than at other times. The content of fat in the body fell progressively from October to May and then increased; initially fat was withdrawn only from the soft tissues but by April and May the fat contents of both skeleton and soft tissues were exceedingly low. The weight of fatfree soft tissue remained relatively constant but was heaviest in July. Fat-free skeleton fraction was lighter in January than in April.

The contents of the predominantly intracellular ions, P, Mg and K in the soft tissue fell between November and January, remained constant between January and May and then increased. There was an increase in Na towards the end of pregnancy followed by a marked fall after parturition. The contents of Ca and P in the skeleton fell between November and January and during lactation between April and July. There was a marked increase between February and April when supplementary feeding was given. Evidence that Mg was selectively removed from the skeleton was obtained in November and January, two sheep having Ca:Mg ratios in skeleton greater than 100. Na and K contents of the skeleton were greatest at the end of pregnancy in April. For the lambs between 6 and 23 kg live weight, each kg of live-weight gain contained 8·8 g Ca, 5·0 g P, 0·27 g Mg, 0·83 g Na and 1·85 g K.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1968

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

Agricultural Research Council (1965). The Nutrient Requirements of Farm Livestock. No. 2 Ruminants. London: A.R.C.Google Scholar
Benzie, D., Cresswell, E., Duckworth, J., Hill, R. & Boyne, A. W. (1961). Radiographic and clinical investigations of the skeleton of Scottish blackface ewes. J. agric. Sci., Camb. 57, 395–9.CrossRefGoogle Scholar
Blaxter, K. L. (1956). The magnesium content of bone in hypomagnesaemic disorders of livestock. Ciba Fdn Symp. (Bone Structure and Metabolism), p. 117.Google Scholar
Blaxter, K. L. (1962). The Energy Metabolism of Ruminants, pp. 63112. London: Hutchison and Co.Google Scholar
Bronner, F., Richelle, L. I., Saville, P. D, Nicholas, J. A. & Cobb, J. R. (1963). Quantitation of calcium metabolism in post-menopausal osteoporosis and in scoliosis. J. clin. Invest. 42, 898.CrossRefGoogle ScholarPubMed
Cresswell, E., Benzie, D. & Boyne, A. W. (1964). Studies of the skeleton of sheep. IX. A further study of the mineralisation of the skeleton of breeding ewes on two Scottish hill farms. J. agric. Sci., Camb. 63, 387–91.CrossRefGoogle Scholar
El Maraghi, N. R. H., Platt, B. S. & Stewart, R. J. C. (1965). The effect of the interaction of dietary protein and calcium on the growth and maintenance of the bones of young, adult and aged rats. Br. J. Nutr. 19, 491509.CrossRefGoogle ScholarPubMed
Field, A. C. & Suttle, N. F. (1966). A method for determining the body composition of sheep based on dissolution of the sheep in nitric acid. Proc. Nutr. Soc. 25, xxiii–xxiv.Google Scholar
Field, A. C. & Suttle, N. F. (1967). Retention of calcium, phosphorus, magnesium, sodium and potassium by the developing sheep foetus. J. agric. Sci., Camb. 69, 417–23.CrossRefGoogle Scholar
Moore, F. D. & Boyden, C. M. (1963). Body cell mass and limits of hydration of the fat-free body: their relation to estimated skeletal weight. Ann. N.Y. Acad. Sci. 110, 6271.CrossRefGoogle ScholarPubMed
Russel, A. J. F. (1967). Nutrition of the pregnant ewe. Rep. Hill Fmg Res. Org. 1964–1967, 5968.Google Scholar
Russel, A. J. F., Gunn, R. G. & Doney, J. M. (1968). Components of weight loss in pregnant hill ewes during winter. Anim. Prod. 10, 4351.CrossRefGoogle Scholar
Smith, R. H. (1964). Hypomagnesaemia in calves. Nord. Vet. Med. 16, Suppl. 1, 143–66.Google Scholar
Widdowson, E. M. & McCance, R. A. (1951). The effect of undernutrition and of pasture on the volume and composition of the body fluids. In ‘Studies of Undernutrition, Wuppertal, 1946–1949’, p. 165. Spec. Rep. Ser. med. Res. Coun. no. 275.Google Scholar