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Diet selection in pigs: choices made by growing pigs when given foods differing in nutrient density

Published online by Cambridge University Press:  18 August 2016

N. S. Ferguson
Affiliation:
Animal Science and Poultry Science Department, University of Natal, P Bag X 01, Scottsville, 3209, South Africa
L. Nelson
Affiliation:
Animal Science and Poultry Science Department, University of Natal, P Bag X 01, Scottsville, 3209, South Africa
R. M. Gous
Affiliation:
Animal Science and Poultry Science Department, University of Natal, P Bag X 01, Scottsville, 3209, South Africa
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Abstract

Two experiments were conducted to corroborate or refute the theory that animals will choose a food that will allow them to use it with maximum efficiency. Pigs have been shown to utilize foods of high nutrient density more efficiently than those of low density, so the choices made by pigs when offered such foods could be used to test the above optimization theory. In experiment 1, 48 Large White × Landrace gilts were used, for an 8-week period starting at 22 kg live weight, while in experiment 2, 48 boars of the same cross but of a genetically improved strain were used from 24 to 60 kg live weight. In both experiments use was made of high nutrient density summit foods which were used alone, or diluted in the ratio 80 summit: 20 milled sunflower husk to provide the low density foods. In experiment 1, the high density diet (HI) contained 7·5 g lysine per kg and 13·20 MJ digestible energy (DE) per kg, whereas in experiment 2 two summit foods were formulated, the first diet (H2) was offered for 3 weeks from 24 kg live weight and the second (H3) followed until 60 kg live weight. Foods H2 and H3 contained 11·0 and 8·40 g lysine per kg respectively and 15·0 and 14·0 MJ DE per kg, respectively. Both experiments made use of a high (H1 and H2, respectively) and a low nutrient density (L1 and L2, respectively) control treatment in which pigs were given ad libitum access to H1 and H2/H3, and L1 and L2/L3 in experiments 1 and 2 respectively (no. =4). In addition, a medium density treatment (Ml) consisting of a 50: 50 mixture of H1 and L1 (no. = 4) was given in experiment 1. Two choice-feeding treatments where used in both experiments, the first in which H1 and H2IH3 were placed in the left bin (CL1 (no. =18) and CL2 (no. = 20), respectively) and the appropriate dilution diet in the right bin, and the second in which H1 and H2/H3 were placed in the right bin (CR1 (no. = 18) and CR2 (no = 20)). There were no differences in average daily growth rates between treatments within experiments but there were significant differences (P < 0·05) in food intakes and efficiency of food utilization (FCE) between treatments. The highest intakes and lowest FCE were obtained on the L1 and L2 treatments while the lowest intakes were recorded on the choice-feeding treatments. There were no significant differences in FCE neither between H1, CL1 and CR1 nor between H2, CL2 and CR2. Only in experiment 1 were there significant differences (P < 0·05) between choice-feeding treatments on the basis of the position of the food bin but there was no preference for a particular position. The results indicated that pigs were able to differentiate successfully between two foods on the basis of their nutrient density, that bin position was not used as a cue in the choice made, that a small amount of the ‘unwanted’ food was consumed throughout the experiment and that the diet selected maximized FCE.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1999

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References

Ball, R. O. and Aherne, F. X. 1987. Influence of dietary nutrient density, level of feed intake and weaning age on young pigs. 1. Performance and body composition. Canadian Journal of Animal Science 67: 10931103.Google Scholar
Belovsky, G. E. 1978. Diet optimisation in a generalist herbivore: the moose. Theoretical Population Biology 14: 105134.Google Scholar
Bradford, M. M. V. and Gous, R. M. 1991a. The response of growing pigs to a choice of diets differing in protein content. Animal Production 52: 185192.Google Scholar
Bradford, M. M. V. and Gous, R. M. 1991b. A comparison of phase feeding and choice feeding as methods of meeting the amino acid requirements of growing pigs. Animal Production 52: 323330.Google Scholar
Bradford, M. M. V. and Gous, R. M. 1992. The response of weaner pigs to a choice of foods differing in protein content. Animal Production 55: 227232.Google Scholar
Cooper, S. D. B. and Kyriazakis, I. 1993. The diet selection of lambs offered food choices of different nutrient density. Animal Production 56: 469A (abstr.).Google Scholar
Cooper, S. D.B., Kyriazakis, I. and Nolan, J. V. 1995. Diet selection in sheep: the role of the rumen environment in the selection of a diet from two feeds that differ in their energy density. British Journal of Nutrition 74: 3954.CrossRefGoogle ScholarPubMed
Emmans, G. C. 1977. The nutrient intake of laying hens given a choice of diets in relation to their protein requirement. British Poultry Science 18: 227236.CrossRefGoogle Scholar
Emmans, G.C., 1991. Diet selection by animals: theory and experimental d esign. Proceedings of the Nutrition Society 50: 5964.CrossRefGoogle Scholar
Emmans, G. C. 1994. Effective energy: a concept of energy utilization applied across species. British Journal of Nutrition 71: 801821.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
Ferguson, N. S. and Gous, R. M. 1997. The influence of heat production on voluntary food intake in growing pigs given protein-deficient diets. Animal Science 64: 365378.CrossRefGoogle Scholar
Gill, B. P., Onibi, G. E. and English, P. R. 1995. Food ingredient selection by growing and finishing pigs: effects on performance and carcass quality. Animal Science 60: 133141.Google Scholar
Gillingham, M. P. and Bunnell, F. L. 1989. Effects of learning on food selection and searching behaviour of deer. Canadian Journal of Zoology 67: 2432.CrossRefGoogle Scholar
Grovum, W. L. 1988. Appetite, palatability and control of food intake. In The ruminant animal: digestive physiology and nutrition (ed. Church, D. C.), pp. 202206. Prentice Hall, Englewood Cliffs.Google Scholar
Holcombe, D.J., Roland, D. A. and Harms, R. H. 1976. The ability of hens to regulate protein intake when offered a choice of diets containing different levels of protein. Poultry Science 55: 17311737.Google Scholar
Illius, A. W. and Gordon, I. J. 1990. Constraints on diet selection and foraging behaviour in mammalian herbivores. In Behavioural mechanisms of food selection (ed. Hughes, R. N.), pp. 369392. Springer-Verlag, Heidelberg.Google Scholar
Kovalčik, K. and Kovalčik, M. 1986. Learning ability and memory testing in cattle of different ages. Applied Animal Behaviour Science 15: 2729.Google Scholar
Krebs, J. R. and McCleery, H. 1984. Optimisation in behavioural ecology. In Behavioural ecology — an evolutionary approach (ed. Krebs, J. R. and Davies, N. B.), pp. 91121. Blackwell, Oxford.Google 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. 1995. The voluntary feed intake of pigs given feeds based on wheat bran, dried citrus pulp and grass meal, in relation to measurements of feed bulk. British Journal of Nutrition 73: 191207.Google Scholar
Kyriazakis, I., Emmans, G. C. and Whittemore, C. T. 1990. Diet selection in pigs: choices made by growing pigs given foods of different protein concentrations. Animal Production 51: 189199.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 Oldham, J. D. 1993. Diet selection in sheep: the ability of growing lambs to select a diet that meets their crude protein (nitrogen × 6-25) requirements. British Journal of Nutrition 69: 617629.Google Scholar
Musten, B., Peace, D. and Anderson, G. A. 1974. Food intake regulation in the weanling rat: self selection of protein and energy. Journal of Nutrition 104: 563572.Google Scholar
Newman, J. A., Parsons, A. J. and Harvey, A. 1992. Not all sheep prefer clover: diet selection revisted. Journal of Agricultural Science, Cambridge 119: 275283.Google Scholar
Parsons, A. J., Newman, J. A., Penning, P. D. and Harvey, A. 1994. Diet preference of sheep: effects of recent diet, physiological state and species abundance. Journal of Animal Ecology 63: 465478.CrossRefGoogle Scholar
Peterson, A. D. and Baumgardt, B. R. 1971. Food and energy intake of rats fed diets varying in energy concentration and density. Journal of Nutrition 101: 10571067.Google Scholar
Provenza, F. D. and Cincotta, R. P. 1993. Foraging as a self-organizational learning process: accepting adaptability at the expense of predictability. In Diet selection: an interdisciplinary approach to foraging behaviour (ed. Hughes, R. N.), pp. 78101. Blackwell, Oxford.Google Scholar
Provenza, F. A., Pfister, J. A. and Cheney, C. D. 1992. Mechanisms of learning in diet selection with reference to phytotoxicosis in herbivores. Journal of Range Management 45: 3645.Google Scholar
Rose, S. P. and Kyriazakis, I. 1991. Diet selection of pigs and poultry. Proceedings of the Nutrition Society 50: 8798.Google Scholar
Rose, S. P. and Michie, W. 1982. The food intakes and growth of choice-fed turkeys offered balancer mixtures of different compositions. British Poultry Science 23: 547554.Google Scholar
Shariatmadari, F. and Forbes, J. M. 1993. Growth and food intake responses to diets of different protein contents and a choice between diets containing two levels of protein in broiler and layer strains of chickens. British Poultry Science 34: 959970.Google Scholar
Tolkamp, B. J. and Ketelaars, J. J. M. H. 1992. Toward a new theory of feed intake regulation in ruminants. 2. Costs and benefits of feed consumption: an optimization approach. Livestock Production Science 30: 297317.Google Scholar
Whittemore, C. 1993. The science and practice of pig production. Longman Scientific and Technical, Essex.Google Scholar