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Diet selection in sheep: the ability of growing lambs to select a diet that meets their crude protein (nitrogen × 6.25) requirements

Published online by Cambridge University Press:  09 March 2007

I. Kyriazakis  and
J. D. Oldham
I. Kyriazakis
Affiliation:
Genetics and Behavioural Sciences Department, SAC Edinburgh, West Mains Road, Edinburgh EH9 3JG
J. D. Oldham
Affiliation:
Genetics and Behavioural Sciences Department, SAC Edinburgh, West Mains Road, Edinburgh EH9 3JG
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Abstract

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To test the proposition that sheep are able to select a diet that meets their crude protein (N × 6.25; CP) requirements, feeds L, A, B, C and H with the same energy content (11 MJ metabolizable energy/kg feed) but different CP contents (78, 109, 141, 172 and 235 g CP/kg fresh feed respectively) were formulated. In addition, feed U, which was feed L plus 21.4 g urea/kg (CP content 132 g/kg), was also made. The feeds were offered ad lib. either singly (n 4 per treatment) or as a choice between feed H and another feed (pairs LH, AH, BH, CH and UH; n 9 per feed pair) to individually penned Suffolk × Scottish mule wether lambs, over the live-weight range 25–45 kg. On the single feeds the rates of live-weight gain were 273, 326, 412, 418, 396 and 407 g/day (SE of difference (SED) 34; P < 0.01) and protein (excluding wool) gain were 27, 32, 44, 45, 41 and 39 g/d (SED 4; P < 0.001) for feeds L, A, B, C, H and U respectively. When sheep were given a choice between a feed below (L or A) and a feed above their CP requirements (H; as judged by the single-feeding treatments) the CP concentration selected was not different between the two pairs: 131 (SE 4) v. 133 (SE 4) g CP/kg feed for pairs LH and AH respectively. On the choices BH and CH (a choice between two feeds above requirements) the feed lower in CP was constantly preferred (874 (SE 33) and 910 (SE 33) g feed B and C respectively per kg total feed intake; CP selected was 157 and 178 g CP/kg respectively). However, this was not the case with the UH choice on which sheep consumed only 599 (SE 61) g feed U/kg total feed intake, resulting in a selection of a higher CP in their diet (173 g CP/kg). The live-weight gains of the animals given a choice between two feeds were 416, 387, 415, 410 and 383 g/d (SED 37) and protein gains were 45, 40, 46, 50 and 43 (SE 7) for pairs LH, AH, BH, CH and UH respectively, which were comparable with the best performance achieved on a single feed. The results suggest that sheep were able to select a diet that meets their CP requirements and avoid, at least to a certain extent, excess of protein intake. It is also possible that sheep discriminate against a property of feed U, such as an excess of urea, when this feed is paired with a feed high in CP.

Keywords

AppetiteFeed preferencesGrowthProtein intakeSheep
Type
Diet selection in sheep
Information
British Journal of Nutrition , Volume 69 , Issue 3 , May 1993 , pp. 617 - 629
Copyright
Copyright © The Nutrition Society 1993

References

Agricultural Research Council (1980). The Nutrient Requirements of Ruminant Livestock. Farnham Royal: Commonwealth Agricultural Bureaux.Google Scholar
Agricultural Research Council (1984). The Nutrient Requirements of Ruminant Livestock, Suppl. 1. Farnham Royal: Commonwealth Agricultural Bureaux.Google Scholar
Chesters, J. K. & Quarterman, J. (1970). Effects of zinc deficiency on food intake and feeding patterns of rats. British Journal of Nutrition 24, 1061–1069.CrossRefGoogle ScholarPubMed
Cropper, M. R. (1987). Growth and development of sheep in relation to feeding strategy. PhD Thesis, University of Edinburgh.Google Scholar
Emmans, G. C. (1991). Diet selection by animals: theory and experimental design. Proceedings of the Nutrition Society 50, 59–64.CrossRefGoogle ScholarPubMed
Freeman, C. P. (1979). The tryptophan requirements of broiler chicks. British Poultry Science 20, 27–37.CrossRefGoogle ScholarPubMed
Harper, A. E. (1974). Amino acid excess. In Nutrients in Processed Foods – Proteins, chapt. 6 [White, P. L. and Fletcher, D. C., editors]. Acton, MA: Publishing Sciences Group Inc.Google Scholar
Hou, X. Z. (1991). Diet selection in sheep. PhD Thesis, University of Edinburgh.Google Scholar
Hespell, R. B. & Bryant, M. P. (1979). Efficiency of rumen microbial growth: Influence of some theoretical and experimental factors on VATP. Journal of Animal Science 49, 1640–1659.CrossRefGoogle Scholar
Kyriazakis, I. (1989). Growth, feed intake and diet selection in pigs: theory and experiments. PhD Thesis, University of Edinburgh.Google Scholar
Kyriazakis, I., Emmans, G. C. & Whittemore, C. T. (1990). Diet selection in pigs: choices made by growing pigs given foods of different protein contents. Animal Production 51, 180–199.Google Scholar
Kyriazakis, I., Emmans, G. C. & Whittemore, C. T. (1991). The ability of pigs to control their protein intake when fed in three different ways. Physiology and Behaviour 50, 1197–1203.CrossRefGoogle ScholarPubMed
Lea, S. E. G. (1979). Foraging and reinforcement schedules in the pigeon: optimal and non-optimal aspects of choice. Animal Behaviour 27, 875–886.CrossRefGoogle Scholar
Milne, J. A. (1991). Diet selection by grazing animals. Proceedings of the Nutrition Society 50, 77–85.CrossRefGoogle ScholarPubMed
Musten, B., Peace, D. & Anderson, G. H. (1974). Food intake regulation in the weaning rat: self-selection of protein and energy. Journal of Nutrition 104, 563–572.CrossRefGoogle Scholar
Newbold, J. R. (1987). Nutrient requirements of intensively reared beef cattle. In Recent Advances in Animal Nutrition, pp. 143–171 [Haresign, W. and Cole, D. J. A., editors]. London: Butterworths.CrossRefGoogle Scholar
Orskov, E. R., McDonald, I., Fraser, C. & Corse, E. L. (1971). The nutrition of the early weaned lamb. III. The effect of ad libitum intake of diets varying in protein concentration on performance and on body composition at different liveweights. Journal of Agricultural Science, Cambridge 77, 351–361.CrossRefGoogle Scholar
Ranhotra, G. S. & Jordan, R. M. (1966). Protein and energy requirements of lambs weaned at six to eight weeks of age as determined by growth and digestion studies. Journal of Animal Science 25, 630–635.CrossRefGoogle ScholarPubMed
Raven, A. M., Forbes, T. J. & Irwin, J. H. D. (1969). The utilisation by beef cattle of concentrate diets containing different levels of milled barley, straw and of protein. Journal of Agricultural Science, Cambridge 73, 355–363.CrossRefGoogle Scholar
Robinson, D. W. (1974). Food intake regulations in pigs. III. Voluntary food selection between protein-free and protein-rich diets. British Veterinary Journal 130, 522–527.CrossRefGoogle Scholar
Robinson, D. W. (1975). Food intake regulations in pigs. IV. The influence of dietary amino acid pattern on free choice food selection in pigs. British Veterinary Journal 131, 707–714.CrossRefGoogle Scholar
Shettleworth, S. J. (1978). Reinforcement and the organisation of behaviour in golden hamsters: punishment of three action patterns. Learning and Motivation 9, 99–123.CrossRefGoogle Scholar