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The response of growing pigs to amino acids as influenced by environmental temperature: tryptophan

Published online by Cambridge University Press:  18 August 2016

N.S. Ferguson  and
R.M. Gous
N.S. Ferguson*
Affiliation:
School of Agricultural Sciences and Agribusiness, Discipline of Animal and Poultry Science, University of Natal, P Bag X 01, Scottsville 3209, South Africa
R.M. Gous
Affiliation:
School of Agricultural Sciences and Agribusiness, Discipline of Animal and Poultry Science, University of Natal, P Bag X 01, Scottsville 3209, South Africa
*
†Email: [email protected]
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Abstract

An experiment was performed to measure the response of young pigs to dietary tryptophan (TRP) concentrations and environmental temperatures. Seventy-two entire male Large White ✕ Landrace pigs were assigned to one of six dietary treatments (2·90 (T1), 2·46 (T2), 2·01 (T3), 1·57 (T4), 1·12 (T5) g/kg and T5 + supplemented TRP (T6)) and one of three temperature treatments (20, 25 and 30°C) at a mean starting live weight of 14·38 (s.e. 0·201)kg. Animals were given ad libitum access to food until a final weight of 26·42 (s.e. 0·479) kg. There were no significant interactions between temperature and dietary TRP on any production variable. There was a significant (P < 0·05) quadratic improvement in the rate of live-weight growth (ADG) as the concentration of dietary TRP increased and as the temperature decreased. However, the response to increasing dietary TRP was independent of the environmental temperature. Maximum ADG was attained on T2 (0·498 (s.e. 0·023) kg/day) and at 20ºC (0·412 (s.e. 0·024) kg/day). Final live weight was a significant (P < 0·001) covariate for ADG and food intake (FI) responses. With TRP as a precursor for serotonin, a neurotransmitter that regulates appetite, it was anticipated that food intake would be affected with decreasing dietary TRP levels. However, there was no response in daily food intake to decreasing TRP concentration. This lack of response in appetite to dietary TRP may have been a result of an increasing TRP to large neutral amino acid ratio, which is known to correlate with an increase in serotonin synthesis. Total heat loss followed a similar response to FI. The gain per unit of food consumed was significantly (P < 0·001) reduced as the TRP content of the diet was decreased. The most efficient treatments were T1 (506 (s.e. 1·90) g gain per kg food) and T2 (495 (s.e. 23·2) g gain per kg food) while the worst was T5 (237 (s.e. 22·3) g gain per kg food). There were significant quadratic responses to dietary TRP in protein content of the empty body (P < 0·05) and the rate of protein retention (PR) (P < 001) but only PR was affected by temperature (P < 001). Both temperature (P < 0·05) and dietary TRP (P < 0·001) had a significant effect on the lipid content of the body but only temperature affected the rate of lipid retention, with a significantly (P < 0·001) lower rate at 30 oC. The efficiency of TRP utilization improved with increasing temperature. It was lowest at 20ºC (0·60 g TRP per kg protein) and highest at 30ºC (0·86 g/kg), while the mean efficiency for pigs between 14 and 26 kg live weight, at thermoneutrality (25°C), was close to 0·71 g/kg.

Keywords

heat losspigstemperaturetryptophan
Type
Non-ruminant nutrition, behaviour and production
Information
Animal Science , Volume 74 , Issue 1 , February 2002 , pp. 103 - 110
Copyright
Copyright © British Society of Animal Science 2002

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References

Blundell, J. E. 1984. Serotonin and appetite. Neuropharmacology 128: 1537–1551.Google Scholar
Burgoon, K. B., Knabe, D. A. and Gregg, J. E. 1992. Digestible tryptophan requirements of starting, growing and finishing pigs. Journal of Animal Science 70: 2493–2501.CrossRefGoogle ScholarPubMed
Ferguson, N. S., Arnold, G. A., Lavers, G. and Gous, R. M. 2000a. The response of growing pigs to amino acids as influenced by environmental temperature. 1. Threonine. Animal Science 70: 287–297.Google Scholar
Ferguson, N. S., Arnold, G. A., Lavers, G. and Gous, R. M. 2000b. The response of growing pigs to amino acids as influenced by environmental temperature. 2. Lysine. Animal Science 70: 299–306.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: 365–378.Google Scholar
Fernstrom, J. D. 1994. The effect of dietary macronutrients on brain serotonin formation. In Appetite and body weight regulation: sugar, fat and macronutrient substitutes (ed. Fernstrom, J. D. and Miller, G. D.), pp. 51–62. CRC Press, Boca Raton.Google Scholar
Fernstrom, J. D. and Wurtman, R. J. 1972. Brain serotonin content: physiological regulation by plasma neutral amino acids. Science 178: 414–416.CrossRefGoogle ScholarPubMed
Forbes, J. M. and Blundell, J. E. 1989. Central nervous control of voluntary food intake. In The voluntary food intake of pigs (ed. Forbes, J. M., Varley, M.A. and Lawrence, T.L.J.), British Society of Animal Production occasional publication no. 13, pp. 7–26.Google Scholar
Genstat. 1993. Genstat version 5 release 3 reference manual. Clarendon Press, Oxford.Google Scholar
Henry, Y. and Sève, B. 1993. Feed intake and dietary amino acid balance in growing pigs with special reference to lysine, tryptophan and threonine. Pig News and Information 14: 35N–43N.Google Scholar
Henry, Y., Sève, B., Colléaux, Y., Ganier, P., Saligaut, C. and Jégo, P. 1992. Interactive effects of dietary levels of tryptophan and protein on voluntary feed intake and growth performance in pigs in relation to plasma free amino acids and hypothalamic serotonin. Journal of Animal Science 70: 1873–1887.Google Scholar
Henry, Y., Sève, B., Mounier, A. and Ganier, P. 1996. Growth performance and brain neurotransmitters in pigs as affected by tryptophan, protein and sex. Journal of Animal Science 74: 2700–2710.Google Scholar
Leathwood, P. L. 1987. Tryptophan availability and serotonin synthesis. Proceedings of the Nutrition Society 46: 143–156.Google Scholar
Li, E. T. S. and Anderson, G. H. 1983. Amino acids in the regulation of food intake. Nutrition Abstracts and Reviews, Series A 53: 169–181.Google Scholar
Meunier-Salaün, M. C., Monnier, M., Colléaux, Y., Sève, B. and Henry, Y. 1991. Impact of dietary tryptophan and behavioral type on behavior, plasma cortisol and brain metabolites of young pigs. Journal of Animal Science 69: 3689–3698.Google Scholar
Pardridge, W. M. 1977. Regulation of amino acid availability to the brain. In Nutrition and the brain (ed. Wurtman, R. J. and Wurtman, J. J.), pp. 141–204. Raven Press, New York.Google Scholar
Sève, B., Meunier-Salaün, M. C., Monnier, M., Colléaux, Y. and Henry, Y. 1991. Impact of dietary tryptophan and behavioral type on growth performance and plasma amino acids of young pigs. Journal of Animal Science 69: 3679–3688.Google Scholar
Whittemore, C. 1993. The science and practice of pig production. Longman Scientific and Technical, Essex.Google Scholar
Wurtman, R. J. 1982. Nutrients that modify brain function. Scientific American 246: 42–51.Google Scholar
Wurtman, R. J. and Wurtman, J. J. 1984. Nutrients, neurotransmitter synthesis and the control of food intake. In Eating and its disorders (ed. Stunkard, A. J. and Stellar, E.), pp. 77–86. Raven Press, New York.Google Scholar