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The nutritional choices of farm animals: to eat or what to eat?

Published online by Cambridge University Press:  27 February 2018

I. Kyriazakis*
Affiliation:
Genetics and Behavioural Sciences Department, Scottish Agricultural College, West Mains Road, Edinburgh, EH9 3JG
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Abstract

Irrespective of whether farm animals are given access to a single homogeneous food or to two or more heterogeneous foods as a choice, their feeding behaviour raises one of two questions (i) how much to eat, and (ii) what to eat? Despite frequent comment to the contrary, their feeding behaviour appears to be goal-orientated rather than random or purposeless. I therefore consider first the goals of farm animals in relation to their feeding behaviour. In general it is accepted that the overall biological framework in which all animals are trying to maximize fitness’ also applies to farm animals. However, some modification is called for in order to account for those situations in which intensive genetic selection has led to relatively ‘unfit’ reproducing animals and for those cases where animals are given access to foods which have not figured in their evolution

On the basis that feeding behaviour is goal orientated, I then consider whether farm animals achieve their goals by monitoring their behaviour in the short or longer term. The conclusion drawn is that while short-term feeding behaviour may be a device to exploit the feeding environment effectively, it is largely unrelated to short-term fluctuations in an animal’s internal state. By contrast, longer-term feeding behaviour is very closely related to longer-term change in internal state, implying the maintenance of close control over feeding behaviour in terms of food intake and diet selection. All animals, including farm animals, are considered to be creatures of habit which maintain habitual feeding behaviour until a change is provoked by a significant alteration in their internal state. Such an alteration requires to be of significantly large magnitude and to be unlike the usual short-term, systematic fluctuations which occur over a day in the profiles of metabolites or hormones. Based on this premise, I contend that the mechanisms by which these disturbances are perceived by the animal will be general rather than specific. The notion that animals can fully achieve their goals by monitoring their feeding behaviour is obviously applicable in situations where they are given appropriate nutritional choices. Where animals are given inadequate or inappropriate choices, as is predominantly the case with farm animals, their feeding behaviour is designed to bring them as close as possible to their goals. Finally I consider the relevance of nutritional choices to farm animals by addressing the possibility of exploiting the goal orientation of feeding behaviour. I conclude that greater recognition of the goal-orientated nature of farm animals’ feeding behaviour can bring benefits in three areas: (i) improved biological understanding of animals’ goals; (ii) improved animal welfare; and (iii) improved animal performance.

Type
Research Article
Copyright
Copyright © The British Society of Animal Science 1997

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References

Asahida, Y. and Mimura, K. 1972. Eating behaviour of chicks to 4 weeks of age. Journal of the Faculty of Fish and Animal Husbandry, Hiroshima University 11: 1522.Google Scholar
Belovsky, G. E. and Schmitz, O. J. 1996. Plant defences and optimal foraging by mammalian herbivores. Journal of Mammalogy 75: 816832.Google Scholar
Blair, R. and Fitzsimons, J. 1970. A note on the voluntary feed intake and growth of pigs given diets containing an extremely bitter compound. Animal Production 12: 529530.Google Scholar
Booth, D. A. 1979. Feeding control systems within ruminants. In Food intake regulations in poultry (ed. Boorman, K. N. and Freeman, B. M.). Proceedings of the fourteenth poultry science symposium, British Poultry Science Ltd, Edinburgh, pp. 1362.Google Scholar
Brown, G. D. and Lynch, J. J. 1972. Some aspects of the water balance of sheep at pasture when deprived of drinking water. Australian Journal of Agricultural Research 23: 669684.CrossRefGoogle Scholar
Campbell, R. G. 1988. Nutritional constraints to lean tissue accretion in farm animals. Nutrition Research Reviews 1: 233253.Google Scholar
Classen, H. L. and Scott, T. A. 1982. Self-selection of calcium during the rearing and early laying periods of white leghorn pullets. Poultry Science 61: 20652074.Google Scholar
Cooper, S. D. B., Kyriazakis, I. and Nolan, J. V. 1995. Diet selection in sheep: the role of the rumen environment on the selection of a diet from two foods that differ in their energy density. British Journal of Nutrition 74: 3954.Google Scholar
Cooper, S. D. B., Kyriazakis, I. and Oldham, J. D. 1994. The effect of late pregnancy on the diet selection made by ewes. Livestock Production Science 40: 263275.CrossRefGoogle Scholar
Deutsch, J. A., Moore, B. O. and Heinrichs, S. C. 1989. Unlearned specific appetite for protein. Physiology and Behavior 46: 619624.Google Scholar
Emmans, G. C. 1981. A model of growth and feed intake of ad libitum fed animals, particularly poultry. In Computers in animal production. British Society of Animal Production occasional publication no. 5, pp. 103110.Google Scholar
Emmans, G. C. 1991. Diet selection by animals: theory and experimental design. Proceedings of the Nutrition Society 50: 5964.Google Scholar
Emmans, G. C. and Kyriazakis, I. 1995. The idea of optimisation in animals: uses and dangers. Livestock Production Science 44: 189197.Google Scholar
Forbes, J. M. 1985. Similarities and differences between intake control mechanisms in pigs, chickens and ruminants. Proceedings of the Nutrition Society 44: 331338.Google Scholar
Forbes, J. M. 1995. Voluntary intake: a limiting factor to production in higher yielding dairy cows? In Breeding and feeding the high genetic merit dairy cow (ed. Lawrence, T. L. J., Gordon, F. J. and Carson, A.), British Society of Animal Science occasional publication no. 19, pp. 1319.Google Scholar
Forbes, J. M. and Covasa, M. 1995. Application of diet selection by poultry with particular reference to whole cereals. World’s Poultry Science Journal 51: 149165.Google Scholar
Fraser, D. 1987. Mineral deficient diets and the pigs attraction to blood: implications for tail-biting. Canadian Journal of Animal Science 67: 909918.Google Scholar
Friggens, N., Shanks, M., Kyriazakis, I., Oldham, J. D. and McClelland, T. H. 1997. The growth and development of nine European sheep breeds. 1. British breeds: Scottish Blackface, Welsh Mountain and Shetland. Animal Science. In press.Google Scholar
Galef, B. 1991. A contravarian view of the wisdom of the body as it relates to dietary self-selection. Psychological Review 98: 218223.Google Scholar
Gill, M. and Romney, D. 1994. The relationship between the control of meal size and the control of daily intake in ruminants. Livestock Production Science 39: 1318.Google Scholar
Harper, A. E. 1974. Amino acid excess. In Nutritients in processed foodsproteins (ed. White, P. L. and Fletcher, D. C.), pp. 4959. Publishing Sciences Group, Acton, Massachusetts.Google Scholar
Hocking, P. M. and McCormack, H. A. 1995. Differential sensitivity of ovarian follicles to gonadotrophin stimulation in broiler and layer lines of domestic fowl. Journal of Reproduction and Fertility 105: 4955.CrossRefGoogle ScholarPubMed
Houston, A. 1990. Foraging in the context of life history: general principles and specific models. In Behavioural mechanism of food selection (ed. Hughes, R. N.), NATO ASI Series G: Ecological Sciences, pp. 2338.Google Scholar
Hughes, B. O. 1979. Appetites for specific nutrients. In Food intake regulation in poultry (ed. Boorman, K. N. and Freeman, B. M.). Proceedings of the fourteenth Poultry Science Symposium, British Poultry Science Ltd, Edinburgh, pp 141169.Google Scholar
Hughes, B. O. and Dewar, W. A. 1971. A specific appetite for zinc in zinc-depleted domestic fowls. British Poultry Science 12: 255258.Google Scholar
Hughes, B. O. and Wood-Gush, D. G. M. 1971. A specific appetite for calcium in domestic chickens. Animal Behaviour 19: 490499.Google Scholar
Jong, A. de. 1981. Short- and long-term effects of eating on blood composition in free-feeding goats. Journal of Agricultural Science 96: 657668.Google Scholar
Kaufman, L. and Collier, G. 1983. Meal-taking by domestic chickens (Gallus gallus) . Animal Behaviour 31: 397404.Google Scholar
Krebs, J. R. and Davies, N. B. 1987. An introduction to behavioural ecology. Blackwell Scientific Publications, Oxford.Google Scholar
Kyriazakis, I. 1989. Growth, feed intake and diet selection in pigs: theory and experiments. Ph.D. thesis, University of Edinburgh.CrossRefGoogle Scholar
Kyriazakis, I. and Emmans, G. C. 1991. Diet selection in pigs: choices made by growing pigs following a period of underfeeding with protein. Animal Production 52: 337346.Google Scholar
Kyriazakis, I. and Emmans, G. C. 1992a. The growth of mammals following a period of nutritional limitation. Journal of Theoretical Biology 156: 485498.Google Scholar
Kyriazakis, I. and Emmans, G. C. 1992b. The selection of a diet by growing pigs given choices between feeds different in their contents of protein and rapeseed meal. Appetite 19: 121132.Google Scholar
Kyriazakis, I., Emmans, G. C. and Whittemore, C. T. 1991. The ability of pigs to control their protein intake when fed in three different ways. Physiology and Behavior 50: 11971203.Google Scholar
Kyriazakis, I. and Gordon, I. J. 1997. Toward a unifying framework of diet selection in domestic animals: marrying nutrition and ecology. Animal Science. In press.Google Scholar
Kyriazakis, I., Lewis, K., Emmans, G. C., Haley, C. S. and Oldham, J. D. 1993. The effect of breed (Large White X Landrace vs purebred Meishan) on the diets selected by pigs given a choice between two foods that differ in their crude protein contents. Animal Production 56: 121128.Google Scholar
Kyriazakis, I. and Oldham, J. D. 1993. Diet selection in sheep: the ability of growing lambs to select a diet that meets their crude protein requirements. British Journal of Nutrition 69: 617629.Google Scholar
Kyriazakis, I., Oldham, J. D., Coop, R. L. and Jackson, F. 1994. The effect of subclinical intestinal nematode infection on the diet selection of growing sheep. British Journal of Nutrition 72: 665677.Google Scholar
Kyriazakis, I. and Savory, C. J. 1997. Hunger and thirst. In Animal welfare (ed. Appleby, M. C. and Hughes, B. O.). CAB International. In press.Google Scholar
Lawrence, A. B. and Illius, A. W. 1997. Measuring preferences and the problems of identifying proximate needs. In Animal choices (ed. Forbes, J. M., Lawrence, T. L. J., Rodway, R. G. and Varley, M. A.), British Society of Animal Science occasional publication no. 20, pp 1926.Google Scholar
Lawrence, A. B., Terlouw, E. M. C. and Kyriazakis, 1.1993. The behavioural effects of undernutrition in confined farm animals. Proceedings of the Nutrition Society 52:219229.CrossRefGoogle ScholarPubMed
Leathwood, P. D. and Ashley, D. K. M. 1983. Behavioural strategies in the regulation of food choice. Experten tia 44: (supplement) 171196.Google Scholar
Leng, R. A. 1990. Factors affecting the utilisation of ‘poor quality’ forages by ruminants particularly under tropical conditions. Nutrition Research Reviews 3: 277303.Google Scholar
Moss, R. 1991. Diet selection — an ecological perspective. Proceedings of the Nutrition Society 50: 7175.Google Scholar
Mraz, F. R., Boucher, R. V. and McCartney, M. G. 1958. The influence of dietary energy and protein on growth responses in chickens. Poultn/ Science 37: 13081313.Google Scholar
Newman, J. A., Parsons, A. J., Thornley, J. H. M., Penning, P. D. and Krebs, J. R. 1995. Optimal diet selection by generalist grazing herbivores. Functional Ecology 9: 255268.Google Scholar
Nielsen, B. L., Lawrence, A. B. and Whittemore, C. T. 1995. Effect of group-size on feeding behaviour, social behaviour, and performance of growing pigs using single-space feeders. Livestock Production Science 44: 7385.Google Scholar
Ogunmodede, B. K. 1981. Vitamin A requirement of broiler chicks in Nigeria. Poultry Science 60: 26222627.CrossRefGoogle ScholarPubMed
Parks, J. R. 1982. A theory of feeding and growth of animals. Springer-Verlag, Berlin.Google Scholar
Pfister, J. A., Cheney, C. D. and Provenza, F. D. 1992. Behavioural toxicology of livestock ingesting toxins. Journal of Range Management 45: 3036.Google Scholar
Poppi, D. P., Gill, M. and France, J. 1994. Integration of theories of intake regulation in growing ruminants. Journal of Theoretical Biology 167:129145.Google Scholar
Provenza, F. D. 1995. Post-ingesti ve feedback as an elementan- determinant of food preference and intake in ruminants. Journal of Range Management 48: 217.Google Scholar
Pym, R- A. E. and Dillon, J. F. 1974. Restricted food intake and reproduction performance of broiler breeder pullets. British Poultry Science 15: 245259.Google Scholar
Robert, S., Matte, J. J. and Girard, C. L. 1991. Effect of feeding regimen on behaviour of growing-finishing pigs supplemented or not supplemented with folie acid. Journal of Animal Science 69:44284436.CrossRefGoogle ScholarPubMed
Rolls, B. J. and Rolls, E. T. 1982. Thirst. Cambridge University Press, Cambridge.Google Scholar
Rose, S. P. and Fuller, M. F. 1995. Choice feeding systems for pigs. In Recent advances in animal nutrition (ed. Garnsworthy, P. C. and Cole, D. J. A.), pp. 211222. Nottingham University Press.Google Scholar
Ryan, W. J. 1990. Compensatory growth in cattle and sheep. Nutrition Abstracts and Reviews (Series B) 60: 653664.Google Scholar
Savory, C. J. 1979. Feeding behaviour. In Food intake regulation in poultry (ed. Boorman, K. N. and Freeman, B. M.). Proceedings of the fourteenth poultry science symposium, British Poultry Science Ltd, Edinburgh, pp. 277323.Google Scholar
Savory, C. J. and Maros, K. 1993. Influence of degree of food restriction, age and time of day on behaviour of broiler breeder chickens. Behavioural Processes 29: 179190.Google Scholar
Shariatmadari, F. and Forbes, J. M. 1992. Feeding behaviour of broiler chickens offered a choice of high- and low-protein foods. Animal Production 54:470 (abstr.).Google Scholar
Shariatmadari, F. and Forbes, J. M. 1994. Diet selection for protein by poultry. World’s Poultry Science Journal 50: 724.Google Scholar
Sibly, R. M., Nott, H. M. R. and Fletcher, D. J. 1990. Splitting behaviour into bouts. Animal Behaviour 39: 6369.Google Scholar
Siegel, P. B. 1993. Behaviour-genetic analyses and poultry husbandry. Poultry Science 72: 16.Google Scholar
Smith, G. S. 1992. Toxification and detoxification of plant compounds by ruminants: an overview. Journal of Range Management 45: 2530.Google Scholar
Stephens, D. W. and Krebs, J. R. 1986. Foraging theory. Princeton University Press, Princeton, NJ.Google Scholar
Taylor, St C. S. 1980. Genetic size-scaling rules in animal growth. Animal Production 30: 161165.Google Scholar
Tolkamp, B. J. and Kyriazakis, I. 1997. Measuring diet selection in dairy cows: effect of training on choice of dietary protein level. Animal Science 64: 197207.Google Scholar
Veerkamp, R. F., Simm, G. and Oldham, J. D. 1995. Genotype by environment interactions: experience from Langhill. In Breeding and feeding the high genetic merit dairy cow (ed. Lawrence, T. L. J., Gordon, F. J. and Carson, A.). British Society of Animal Science occasional publication no. 19, pp. 5966.Google Scholar
Whittemore, C. T., Tullis, J. B. and Emmans, G. C. 1988. Protein growth in pigs. Animal Production 44: 437445.Google Scholar
Ydenberg, R. C., Welham, C. V. J., Schmid-Hempel, R., Schmid-Hempel, P. and Beauchamp, G. 1994. Time and energy constraints and the relationship between currencies in foraging theory. Behavioural Ecology 5: 2834.Google Scholar
Zemmelink, G. 1980. Effect of selective consumption on voluntary intake and digestibility of tropical forages. Ph.D. thesis, University of Wageningen, The Netherlands.Google Scholar