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Effects of dietary unsaturated fat and of protein source on melting point and fatty acid composition of lamb fat

Published online by Cambridge University Press:  27 March 2009

M. J. Gibney  and
J. L. L'estrange
M. J. Gibney
Affiliation:
Department of Agricultural Chemistry, University College, Glasnevin, Dublin 9
J. L. L'estrange
Affiliation:
Department of Agricultural Chemistry, University College, Glasnevin, Dublin 9
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Summary

Four groups of six store lambs were offered ad libitum a concentrate barley-based diet, supplemented with either 8% casein or 2% urea, each contributing the same level of nitrogen to the diet and each fed with or without a supplement of 5·8% sunflower oil. Daily food intake was significantly affected by treatment but there was no significant treatment effect on live-weight gain or food conversion efficiency. In rumen fluid the casein supplement resulted in more total volatile fatty acids and a greater proportion of valeric acid, while the sunflower oil supplement significantly increased the proportion of propionic acid. Sunflower oil supplementation decreased the melting point of perinephric fat by about 3 °C, associated with an increase in the proportions of palmitoleic, oleic, linoleic and linolenic acids and a decrease in the proportions of palmitic and stearic acids. Sunflower oil resulted in a smaller and nonsignificant decrease in the melting point of subcutaneous fat which was associated with an increase in the proportions of linoleic and linolenic acid and a decrease in the proportion of palmitic acid. Melting point of both fats was not affected by source of dietary nitrogen supplementation but in subcutaneous fat the urea supplement resulted in a small increase in the proportion of oleic acid and a decrease in the proportions of palmitic and palmitoleic acids. The proportions of branched-chain and oddnumbered n-acids in both fats were not affected by treatment.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 84 , Issue 2 , April 1975 , pp. 291 - 296
Copyright
Copyright © Cambridge University Press 1975

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References

REFERENCES

Andrews, R. P. & Ørskov, E. R. (1970). A note on the effect of bulk density and digestibility on the voluntary intake of concentrate diets by sheep of two ages. Animal Production 12, 335–8.Google Scholar
Clifford, A. J. & Tillman, A. D. (1968). Urea and Isolated Soyabean Protein in Sheep Purified Diets. Journal of Animal Science 27, 484–9.CrossRefGoogle Scholar
Davies, C. L. & Brown, R. E. (1970). Low-fat milk syndrome. In Physiology of Digestion and Metabolism in the Ruminant (ed. Phillipson, A. T.), pp. 545–565. Oriel Press: Newcastle-upon-Tyne.Google Scholar
Devier, C. V. & Pfander, W. H. (1974). Source and level of dietary fat on fatty acid and cholesterol in lambs. Journal of Animal Science 38, 669–75.CrossRefGoogle ScholarPubMed
Duncan, W. R. H., Ørskov, E. R. & Garton, G. A. (1972). Fatty acid composition of lambs fed on barley-based diets. Proceedings of the Nutritional Society 31, 19A–20A.Google ScholarPubMed
Garton, G. A., Howell, F. D. Del. & Duncan, W. R. H. (1972). Influence of dietary volatile fatty acids on the fatty acid composition of lamb triglycerides with special reference to the effect of propionate on the presence of branched-chain compounds. British Journal of Nutrition 23, 409–16.CrossRefGoogle Scholar
Gibney, M. J. & L'estrange, J. L. (1973). Dietary influence on lamb fat composition. Irish Journal of Agricultural Research 12, Supplement pp. vii–viii.Google Scholar
Grigor, M. R., Dunckley, G. G. & Purves, H. D. (1970). The synthesis of branched-chain fatty acids of rat skin surface lipid. Biochimica Biophysics Ada 218, 389–99.CrossRefGoogle ScholarPubMed
Lassiter, J. W. (1968). Effect of dietary fat source and buffer level on composition of depot fats, gains and liver manganese of sheep. Journal of Animal Science 27, 1466–71.CrossRefGoogle Scholar
L'estrange, J. L. & Mulvihill, T. A. (1975). A survey of fat characteristics of lamb with particular reference to the soft fat condition in intensively fed lambs. Journal of Agricultural Science, Cambridge 84, 281–90.CrossRefGoogle Scholar
Murphy, J. (1974). Effects of diet on composition and quality of lamb fat. M.Agr.Sc. Thesis, National University of Ireland.Google Scholar
Ørskov, E. R., Fraser, C., Gill, J. C. & Corse, E. L. (1971). The effect in an intensive production system of type of cereal and time of weaning on the performance of lambs. Animal Production 13, 485–92.Google Scholar
Park, R. J., Corbett, J. L. & Furnival, E. P. (1972). Flavour differences in meat from lambs grazed on lucerne (Medicago sativa) or phalaris (Phalaris tuberosa) pastures. Journal of Agricultural Science, Cambridge 78, 47–52.CrossRefGoogle Scholar
Park, R. J., Spurway, R. A. & Wheeler, J. L. (1972). Flavour differences in meat from sheep grazed on pasture or winter forage crops. Journal of Agricultural Science, Cambridge 78, 53–6.CrossRefGoogle Scholar
Rhodes, D. N. (1971). A comparison of the quality of meat from lambs reared intensively indoors and conventionally on grass. Journal of the Science of Food and Agriculture 22, 667–8.CrossRefGoogle ScholarPubMed
Shaw, J. C. & Ensor, W. L. (1959). Effect of feeding cod liver oil and unsaturated fatty acids on rumen volatile fatty acids and milk fat content. Journal of Dairy Science 42, 1238–40.CrossRefGoogle Scholar