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Studies on protein utilization by ewes during lactation

Published online by Cambridge University Press:  02 September 2010

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

A total of 64 Border Leicester × Greyface ewes were offered eight diets comprising four levels of digestible crude protein and two levels of metabolizable energy (ME) intake during gestation. After parturition the ewes on each gestation treatment were offered a high or low level of ME intake at a constant level of crude protein intake. Nitrogen balances were carried out on all ewes during weeks three and four of lactation.

Digestibility coefficients and output of nitrogen in the milk measured during the lactation balance periods were not significantly affected by the gestation treatments. Body nitrogen balance during lactation was significantly affected by the level of protein offered during gestation.

Empirical equations relating digestible crude protein intake and ME intake to milk nitrogen production and body nitrogen balance indicated that a digestible crude protein intake of 7·9 g/kg W0·75 per day and a ME intake of 220 kcals/kg W0·75 per day resulted in the production of 0·70 g milk nitrogen per kg W0·75 or approximately 100 g of milk per kg W0·75. The corresponding level of body nitrogen retention was 0·162 g/kg W0·75 per day and showed no consistent trend due to level of protein intake during gestation.

Type
Research Article
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
Blaxter, K. L. and Wainman, F. W. 1964. The utilisation of the energy of different rations by sheep and cattle for maintenance and for fattening. J. agric. Sci., Camb. 63: 113128.CrossRefGoogle Scholar
Forbes, T. J. and Robinson, J. J. 1969. A study of the energy requirements of weaned lambs. Anim.Prod. 11: 389397.Google Scholar
Gardner, R. W. and Hogue, D. E. 1964. Effects of energy intake and number of lambs suckled on milk yield, milk composition and energetic efficiency of lactating ewes. J. Anim. Sci. 23: 935942.CrossRefGoogle Scholar
Gardner, R. W. and Hogue, D. E. 1966. Milk production, milk composition and energetic efficiency of Hampshire and Corriedale ewes fed to maintain bodyweight. J. Anim. Sci. 25: 789795.CrossRefGoogle Scholar
Hadjtpieris, G., Jones, J. G. W., Wimble, R. H. and Holmes, W. 1966. Studies on feed intake and feed utilisation by sheep. 2. The utilisation of feed by ewes. J. agric. Sci., Camb. 66: 341349.CrossRefGoogle Scholar
Hogue, D. E. 1967. Protein requirements of lactating ewes. Proc. Cornell Nutr. Conf., pp. 118122.Google Scholar
Lloyd, L. E., Peckham, H. E. and Crampton, E. W. 1956. The effect of change of ration on the required length of preliminary feeding period in digestion trials with sheep. J. Anim. Sci. 15: 846853.CrossRefGoogle Scholar
Morrison, F. B. 1959. Feeds and Feeding. 22nd ed.Morrison Publishing Co., Iowa.Google Scholar
National Research Council. 1968. Nutrient requirements of sheep. Publs natn. Res. Coun. (Wash.), No. 1693.Google Scholar
Robinson, J. J. 1966. A study of the feed requirements of the breeding ewe with particular reference to protein utilisation. Ph.D. Thesis, Queen's University, Belfast.CrossRefGoogle Scholar
Robinson, J. J. and Forbes, T. J. 1966. A study of the protein requirements of the mature breeding ewe. 1. Maintenance requirement of the non-pregnant ewe. Br. J. Nutr. 20: 263272.CrossRefGoogle Scholar
Robinson, J. J. and Forbes, T. J. 1967. A study of the protein requirements of the mature breeding ewe. 2. Protein utilisation in the pregnant ewe. Br. J. Nutr. 21: 879891.CrossRefGoogle ScholarPubMed
Robinson, J. J. and Forbes, T. J. 1968. The effect of protein intake during gestation on ewe and lamb performance. Anim. Prod. 10: 297309.Google Scholar
Robinson, J. J. and Forbes, T. J. 1970. The effect of roughage to concentrate ratio in the diet on protein and energy utilisation by the non-pregnant ewe. J. agric. Sci., Camb. 74: 415421.CrossRefGoogle Scholar
Rook, J. A. F. and Line, C. 1961. The effect of the plane of energy nutrition of the cow on the secretion in milk of the constituents of the solids-not–fat fraction and on the concentrations of certain blood-plasma constituents. Br. J. Nutr. 15: 109119.CrossRefGoogle ScholarPubMed
Stielau, W. J. 1960. The length of the preliminary feeding period required in digestibility experiments with sheep. S. Afr. J. agric. Sci. 3: 433439.Google Scholar