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A study of protein utilization by weaned lambs

Published online by Cambridge University Press:  02 September 2010

J. J. Robinson  and
T. J. Forbes
J. J. Robinson
Affiliation:
Agricultural Research Institute of Northern Ireland, Hillsborough, Co. Down and The Queen's University of Belfast
T. J. Forbes
Affiliation:
Agricultural Research Institute of Northern Ireland, Hillsborough, Co. Down and The Queen's University of Belfast
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Summary

Fifty weaned store lambs approximately 7-month-old were used in an experiment designed to assess their protein requirements and utilization. At the beginning of the experiment a random sample of 10 animals were slaughtered and their loin joints analysed. The remaining 40 were allocated at random to four dietary treatments (T1, T2, T3, T4) comprising four crude protein intakes at a constant energy intake. The experiment was divided into two periods. During period 1 (48 days) the dietary crude protein intakes were 58 (T1), 111 (T2), 170 (T3), and 198 (T4) g/day with a mean digestible organic matter intake (DOMI) of 578 g/day. During period 2 (55 days) the corresponding crude protein intakes were 89, 157, 215, 251 and the DOMI was 678 g/day.

Digestibility and nitrogen balance trials were carried out on two animals from each treatment in period 1 and on six animals on each treatment in period 2. At slaughter the loin joints from five animals on each dietary treatment were chemically analysed.

The only significant effect on live-weight gain of varying protein intake was a lower gain on the lowest protein intake (T1) in period 1. It was estimated that the optimum ratio of digestible protein intake (g) to digestible energy intake (meals) for live-weight gain in period 1 was approximately 30 : 1 and in period 2 approximately 21 : 1. There was a significant increase in killing-out percentage with increasing crude protein intake. The digestibility of dry matter and nitrogen increased with increasing crude protein intake. There was a significant quadratic relationship between the apparently digested nitrogen intake in g/day (X) and nitrogen retained in g/day (Y). The regression equation was

Y = −0·008X2 + 0·537X + 0·682

Liver copper levels decreased with increasing crude protein con-centration in the diets.

Type
Research Article
Information
Animal Production , Volume 12 , Issue 1 , February 1970 , pp. 95 - 105
Copyright
Copyright © British Society of Animal Science 1970

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References

REFERENCES

Agricultural Research Council. 1965. The Nutrient Requirements of Farm Livestock. No. 2. Ruminants. Agricultural Research Council, London.Google Scholar
Balch, C. C. 1967. Problems in predicting the value of non-protein nitrogen as a substitute for protein in rations for farm ruminants. World Review Anim. Prod. 3: No. 14, 84–91.Google Scholar
Brown, N. A. and Hemingway, R. G. 1962. A rapid method for the determination of copper in biological tissues by means of zinc dibenzyldithiocarbomate. Res. vet. Sci. 3: 345–347.CrossRefGoogle Scholar
Davies, P. J. 1966. A note on energy intake and nitrogen balance of fattening lambs given all-concentrate diets. Anim. Prod. 8: 341–344.Google Scholar
Doney, J. M. 1966. Breed differences in response of wool growth to annual nutritional and climatic cycles. J. agric. Sci., Camb. 67: 25–30.CrossRefGoogle Scholar
Elliott, R. C. and Topps, J. H. 1963. Voluntary intake of low protein diets by sheep. Anim. Prod. 5: 269–276.Google Scholar
Forbes, T. J. and Robinson, J. J. 1969. A study of the energy requirements of weaned lambs. Anim. Prod. 11: 389–397.Google Scholar
Hemingway, R. G. and MacPherson, A. 1967. Progress in Livestock Nutrition 1962–67. Tech. Pubi. U.S. Feed Grains Council.Google Scholar
Jones, J. R. and Hogue, D. E. 1960. Effect of energy level on the protein requirement of lambs fattened with and without stilboestrol. J. Anim. Sci. 19: 1049–1054.CrossRefGoogle Scholar
Kay, M., Bowers, H. B. and McKiddie, G. 1968. The protein requirements of rapidly growing steers. Anim. Prod. 10: 37–42.CrossRefGoogle Scholar
Kirton, A. H., Barton, R. A. and Rae, A. L. 1962. The efficiency of determining the chemical composition of lamb carcasses. J. agric. Sci., Camb. 58: 381–386.CrossRefGoogle Scholar
Lodge, G. A. 1966. Feeding indoor sheep. Agriculture, Lond. 73: 113–117.Google Scholar
MacPherson, A. and Hemingway, R. G. 1967. Copper storage in Blackface lambs fattened on cereal-based diets. Anim. Prod. 9: 282 (Abstr.).Google Scholar
Martin, A. K. 1966. Some errors in the determination of nitrogen retention of sheep by nitrogen balance studies. Br. J. Nutr. 20: 325–337.CrossRefGoogle ScholarPubMed
Pálsson, H. and Vergés, J. S. 1952. Effects of the plane of nutrition on growth and the development of carcass quality in lambs. 1. The effects of high and low planes of nutrition at different ages. J. agric. Sci., 42: 1–92.CrossRefGoogle Scholar
Preston, R. L. 1966. Protein requirements of growing-finishing cattle and lambs. J. Nutr. 90: 157–160.CrossRefGoogle ScholarPubMed
Preston, R. L. and Burroughs, W. 1958. Stilbestrol responses in lambs fed rations differing in calorie to protein ratios. J. Anim. Sci. 17: 140–151.CrossRefGoogle Scholar
Preston, R. L., Schnakenberg, D. D. and Pfander, W. H. 1965. Protein utilization in ruminants. 1. Blood urea nitrogen as affected by protein intake. J. Nutr. 86: 281–288.CrossRefGoogle Scholar
Robinson, J. J. and Forbes, T. J. 1966. A study of protein requirements of the mature breeding ewe. 1. Maintenance requirement of the non-pregnant ewe. Br. J. Nutr. 20: 263–272.CrossRefGoogle Scholar
Robinson, J. J. and Forbes, T. J. 1967. A study of the protein requirements of the mature breeding ewe. 2. Protein utilization in the pregnant ewe. Br. J. Nutr. 21: 879–891.CrossRefGoogle ScholarPubMed
Steel, R. G. D. and Torrie, J. H. 1960. In Principles and Procedures of Statistics. McGraw-Hill Book Co, New York, Toronto and London.Google Scholar
Tagari, H., Dror, Y., Ascarelli, I. and Bondi, A. 1964. The influence of levels of pro-tein and starch in rations of sheep on the utilization of protein. Br. J. Nutr. 18: 333–356.CrossRefGoogle Scholar
Todd, J. R. 1969. Chronic copper toxicity of ruminants. Proc. Nutr. Soc. 28: 189–198.CrossRefGoogle Scholar