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Nutrition of chicks and layers

Published online by Cambridge University Press:  18 September 2007

T.R. Morris
T.R. Morris
Affiliation:
Department of Agriculture, University of Reading, Earley Gate, Reading, RG6 6AR, United Kingdom, e-mail: [email protected]
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Abstract

When formulating least-cost poultry diets, ME concentration should be optimised by an iterative procedure, not entered as a fixed value. This iteration must calculate profit margins by taking into account the way in which feed intake and saleable outputs vary with ME concentration.

In the case of broilers, adjustment of critical amino acid contents in direct proportion to ME concentration does not result in birds of equal fatness. To avoid an increase in fat deposition at higher energy levels, it is proposed that amino acid specifications should be adjusted in proportion to changes in the net energy supplied by the feed. A model is available which will both interpret responses to amino acids in laying trials and give economically optimal estimates of amino acid inputs for practical feed formulation. Flocks coming into lay and flocks nearing the end of the pullet year have bimodal distributions of rates of lay, with the result that calculations of requirement based on mean output will underestimate the optimal amino acid input for the flock.

Chick diets containing surplus protein can lead to impaired utilisation of the first-limiting amino acid. This difficulty can be avoided by stating amino acid requirements as a proportion of the protein.

Keywords

energyproteinamino acidsnutrient density
Type
Reviews
Information
World's Poultry Science Journal , Volume 60 , Issue 1 , March 2004 , pp. 5 - 18
Copyright
Copyright © Cambridge University Press 2004

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References

Abebe, S. and Morris, T.R. (1990) Effects of protein concentration on responses to dietary tryptophan by chicks. British Poultry Science 31: 267–272.CrossRefGoogle ScholarPubMed
Brody, S. (1945) Relation of basal metabolism to body weight of mature animals in different species. In: Bioenergetics und Growth (Brody, S.), New York, Hafner Publishing Company, pp. 368–374.Google Scholar
Clark, F.A., Gous, R.M. and Morris, T.R. (1982) Response of broiler chicks to well-balanced protein mixtures. British Poultry Science 23: 433–446.CrossRefGoogle Scholar
Curnow, R.N. (1973) A smooth population response curve based on an abrupt threshold and plateau model for individuals. Biometrics 29: 1–10.Google Scholar
Emmans, G.C. (1994) Effective energy: a concept of energy utilisation applied across species. British Journal of Nutrition 71: 801–821.CrossRefGoogle ScholarPubMed
Fisher, C., Morris, T.R. and Jennings, R.C. (1973) A model for the description and prediction of responses of laying hens to amino acid intake. British Poultry Science 52: 423–445.Google Scholar
Fisher, C. and Wilson, B.M. (1974) Response to dietary energy concentration by growing chickens. In: Energy Requirements of Poultry (Morris, T.R. and Freeman, B.M., Eds), Edinburgh, Constable, pp. 151–184.Google Scholar
Gous, R.M., Emmans, G.C., Broadbent, L.A. and Fisher, C. (1990) Nutritional effects on the growth and fatness of broilers. British Poultry Science 31: 495–505.CrossRefGoogle ScholarPubMed
Gous, R.M., Griessel, M. and Morris, T.R. (1987) The effect of dietary energy concentration on the response of laying hens to amino acids. British Poultry Science 28: 427–436.CrossRefGoogle ScholarPubMed
Hill, F.W. (1962) Some aspects of the physiology of food intake and digestion in chickens. In: Nutrition of Pigs und Poultry (Morgan, J.T. and Lewis, D., Eds), London, Butterworths, pp. 3–17.Google Scholar
Huyghebaert, G., De Groote, G., Butler, E.A. and Morris, T.R. (1991) Optimum isoleucine requirement of laying hens and the effect of age. British Poultry Science 32: 471–481.CrossRefGoogle ScholarPubMed
Jackson, N., KiRkpatrick, H.R. and Fulton, R.B. (1969) An experimental study of the utilisation, by the laying hen, of dietary energy partially supplied as animal fat. British Poultry Science 10: 115–126.CrossRefGoogle ScholarPubMed
McDonald, M.W. and Morris, T.R. (1985) Quantitative review of optimum amino acid intakes for young laying pullets. British Poultry Science 26: 253–264.CrossRefGoogle ScholarPubMed
Morris, T.R. (1968) The effect of dietary energy level on the voluntary calorie intake of laying birds. British Poultry Science 9: 285–295.CrossRefGoogle Scholar
Morris, T.R. (1969) Nutrient density and the laying hen. Proceedings of the 3rd Nutrition Conference for Feed Manufactures (Swan, H. and Lewis, D., Eds), University of Nottingham, pp. 103–114.Google Scholar
Morris, T.R., Al-Azzawi, K., Gous, R.M. and Simpson, G.L. (1987) Effects of protein concentration on responses to dietary lysine by chicks. British Poultry Science 28: 185–195CrossRefGoogle ScholarPubMed
Morris, T.R. and Blackburn, H.A. (1982) The shape of the response curve relating protein intake to egg output for laying hens. British Poultry Science 23: 405–424CrossRefGoogle Scholar
Morris, T.R. and Gous, R.M. (1988) Partitioning of the response to protein between egg number and egg weight. British Poultry Science 29: 93–99CrossRefGoogle ScholarPubMed
Morris, T.R., Gous, R.M. and Abebe, S. (1992) Effects of dietary protein concentration on the responses of growing chicks to methionine. British Poultry Science 33: 795–803CrossRefGoogle ScholarPubMed
Morris, T.R. and Wethli, E. (1978) The tryptophan requirements of young laying pullets. British Poultry Science 19: 455–464CrossRefGoogle ScholarPubMed
Pilbrow, P.J. and Morris, T.R. (1974) Comparison of lysine requirements amongst eight stocks of laying fowl. British Poultry Science 15: 51–73CrossRefGoogle ScholarPubMed
Wethli, E. and Morris, T.R. (1978) Effect of age on the tryptophan requirements of laying hens. British Poultry Science 19: 559–565CrossRefGoogle ScholarPubMed
Wethli, E., Morris, T.R. and Shreshta, T.P. (1975) The effect of feeding high levels of low quality proteins to growing chickens. British Journal of Nutrition 34: 363–373.Google ScholarPubMed