Hostname: page-component-848d4c4894-wzw2p Total loading time: 0 Render date: 2024-05-05T14:18:58.162Z Has data issue: false hasContentIssue false

Microbial amino acid synthesis and utilization in rats: the role of coprophagy

Published online by Cambridge University Press:  09 March 2007

David Torrallardona
Affiliation:
The Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB2 9SB
C. Ian Harris
Affiliation:
The Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB2 9SB
Malcolm F. Fuller
Affiliation:
The Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB2 9SB
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Four rats were housed in cages with mesh floors; another four rats were housed in tubular anti-coprophagy cages, in which they could not turn round to reach their own faeces. Both groups were fed for 6 d on a low-protein diet containing fermentable carbohydrates and 15NH4Cl. At the end of the experiment the rats were killed and their carcasses were homogenized, lysine was isolated by ion-exchange chromatography and its 15N enrichment measured by isotope-ratio mass spectrometry. The 15N enrichment in the lysine of the microbial fraction of faeces and the total amount of lysine in the body were also determined in order to estimate the amount of microbial lysine absorbed. The 15N enrichment in body lysine of non-coprophagic rats was not different from that previously measured in rats given unlabelled NH4Cl, but in coprophagic rats it was significantly higher. The daily absorption of microbial lysine by the coprophagic rats accounted for 20·7 (SE 2·55) mg/kg body weight0·75 but was only 0·5 (SE 1·04) mg/kg body weight0·75 for the non-coprophagic rats. This value was not significantly different from zero. The utilization of microbial amino acids via coprophagy resulted in a higher weight gain (adjusted for intake) in the coprophagic group (15·5 g/6 d) than in the non-coprophagic rats (3·1 g/6 d). It was concluded that, in rats, the utilization of microbial lysine occurred exclusively via coprophagy.

Type
Animal Nutrition
Copyright
Copyright © The Nutrition Society 1996

References

REFERENCES

Barnes, R. H. & Fiala, G. (1959). Effects of the prevention of coprophagy in the rat. VI. Vitamin K. Journal of Nutrition 68, 603614.CrossRefGoogle Scholar
Barnes, R. H., Fiala, G., McGhee, B. & Brown, A. (1957). Prevention of coprophagy in the rat. Journal of Nutrition 63, 489498.CrossRefGoogle ScholarPubMed
Bender, A. E. (1960). Correlation of amino acid composition with nutritive value of proteins. Clinica Chimica Acta 5, 15.CrossRefGoogle ScholarPubMed
Benditt, E. P., Woolridge, R. L., Steffee, C. H. & Frazier, L. E. (1950). Studies in amino acid utilization. IV. The minimum requirements of the indispensable amino acids for maintenance of the adult well-nourished male albino rat. Journal of Nutrition 40, 335350.CrossRefGoogle Scholar
Dreyer, J. J. (1975). Biological assessment of protein quality. Essential amino acid requirements of young rats in certain states of nitrogen balance. South African Medical Journal 49, 16671673.Google ScholarPubMed
Jackson, A. A. (1995). Salvage of urea-nitrogen and protein requirements. Proceedings of the Nutrition Society 54, 535547.CrossRefGoogle ScholarPubMed
Just, A., Jørgensen, H. & Fernández, J. A. (1981). The digestive capacity of the caecum-colon and the value of the nitrogen absorbed from the hind gut for protein synthesis in pigs. British Journal of Nutrition 46, 209219.CrossRefGoogle ScholarPubMed
Metta, V. C., Nash, L. & Johnson, B. C. (1961). A tubular coprophagy-preventing cage for the rat. Journal of Nutrition 74, 473476.CrossRefGoogle Scholar
Midvedt, T. & Gustafsson, B. E. (1981). Digestion of dead bacteria by germ-free rats. Current Microbiology 6, 1315.CrossRefGoogle Scholar
Minitab Inc. (1989). MINITAB.State College, PA: Minitab Inc.Google Scholar
National Research Council (1995). Nutrient Requirements of Laboratory Animals. Washington, D.C.: National Academy Press.Google Scholar
Neale, R. J. & Waterlow, J. C. (1974). Critical evaluation of a method for estimating amino acid requirements for maintenance in the rat by measurement of the rate of 14C-labelled amino acid oxidation in vivo. British Journal of Nutrition 32, 257272.CrossRefGoogle Scholar
Rolls, B. A. (1970). Factors influencing the digestion and absorption of protein in the rat. PhD Thesis, University of Reading.Google Scholar
Said, A. K. & Hegsted, D. M. (1970). Response of adult rats to low dietary levels of essential amino acids. Journal of Nutrition 100, 13631376.CrossRefGoogle ScholarPubMed
Schmitz, M., Ahrens, F., Schön, J. & Hagemeister, H. (1991). Amino acid absorption and its significance for protein supply in the pig. In Digestive Physiology in Pigs. Proceedings of the Vth International Symposium on Digestive Physiology in Pigs, pp. 8587 [Verstegen, M. W. A.Huisman, J. and Hartog, L. A. den editors]. Wageningen: Pudoc.Google Scholar
Smith, E. B. & Johnson, B. C. (1967). Studies of amino acid requirements of adult rats. British Journal of Nutrition 21, 1727.CrossRefGoogle ScholarPubMed
Torrallardona, D. (1994). The contribution of the gastrointestinal microflora to the amino acid requirements of non-ruminants. PhD Thesis, University of Aberdeen.Google Scholar
Torrallardona, D., Harris, C. I., Coates, M. E. & Fuller, M. F. (1996). Microbial amino acid synthesis and utilization in rats: incorporation of 15N from 15NH4Cl into lysine in the tissues of germ-free and conventional rats. British Journal of Nutrition 76, 689700.CrossRefGoogle ScholarPubMed
Torrallardona, D., Harris, C. I., Milne, E. & Fuller, M. F. (1993). Contribution of intestinal microflora to lysine requirements in nonruminants. Proceedings of the Nutrition Society 52, 153A.Google Scholar
Torrallardona, D., Harris, C. I., Milne, E. & Fuller, M. F. (1994 a). Role of coprophagy in the utilization of microbial lysine by rats. Proceedings of the Nutrition Society 53, 109A.Google Scholar
Torrallardona, D., Harris, C. I., Milne, E. & Fuller, M. F. (1994 b). The contribution of intestinal microflora to amino acid requirements in pigs. In Proceedings of the VIth International Symposium on Digestive Physiology in Pigs. European Association of Animal Production Publication no. 80, pp. 245248 [Souffrant, w. B. and Hagemeister, H. editors]. Dummerstorf: Forschungsinstitut für die Biologie landwirtschaftlicher Nutztiere.Google Scholar
Torrallardona, D., Harris, C. I., Milne, E. & Fuller, M. F. (1995). Site of absorption of lysine synthesis by the gastrointestinal microflora of pigs. In Proceedings of the VII International Symposium on Protein Metabolism and Nutrition. European Association of Animal Production Publication no. 81, pp. 369371 [Nunes, A. F.Portugal, A. V.Costa, J. P. and Ribeiro, J. R. editors]. Santarém, Portugal: Estacao Zooténica Nacional.Google Scholar
Wünsche, J., Hennig, U., Meinl, M. & Bock, H.-D. (1984). Amino acid absorption from the caecum of growing pigs. In Proceedings of the VI International Symposium on Amino Acids, pp. 158167 [Zebrowska, T.Buraczewska, L.Buraczewska, S.Kowalczyk, J. and Pastuzewska, B. editors]. Warsaw: Polish Scientific Publishers.Google Scholar
Zebrowska, T. (1973). Digestion and absorption of nitrogenous compounds in the large intestine of pigs. Roczniki Nauk Rolniczych 95B, 8590.Google Scholar