Hostname: page-component-5c6d5d7d68-tdptf Total loading time: 0 Render date: 2024-08-14T19:04:53.088Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects on wool growth of the infusion of mixtures of amino acids into the abomasum of sheep

Published online by Cambridge University Press:  27 March 2009

P. J. Reis  and
D. A. Tunks
P. J. Reis
Affiliation:
Division of Animal Production, C.S.I.R.O., Ian Clunies Ross Animal Research Laboratory, P.O. Box 239, Blacktoum, N.S.W., 2148, Australia
D. A. Tunks
Affiliation:
Division of Animal Production, C.S.I.R.O., Ian Clunies Ross Animal Research Laboratory, P.O. Box 239, Blacktoum, N.S.W., 2148, Australia
Get access Rights & Permissions [Opens in a new window]

Summary

Merino sheep were given abomasal infusions of either mixtures of amino acids or protein during periods of 8 or 12 days. Effects on wool growth were measured using autoradiography and a clipping procedure which allowed time for the emergence of the wool fibres. Estimates of volume growth rate, from the autoradiographic measurements, and of mass of wool grown, from clipping, were in good agreement.

An infusion of a standard mixture of 13 amino acids, which included ten essential amino acids in approximately the proportions in casein, consistently stimulated wool growth. The mean increases in volume and mass of wool grown, during 30 infusions, were 66 and 67% respectively. A mixture of ten essential amino acids alone appeared to be as effective as the standard mixture for stimulating wool growth, and there were no significant differences between the effects on wool growth of casein and the standard mixture of amino acids.

The omission of methionine from an infusion of the standard mixture of amino acids, or from a mixture of essential amino acids only, inhibited wool growth rate; both fibre diameter and length of wool grown per day were reduced to below the control values. In addition, the strength of the fibres was considerably reduced.

Infusions of zein and of an amino acid mixture simulating the essential amino acid composition of zein both inhibited wool growth rate, due to a reduction in fibre diameter. Similar effects on wool growth were observed when any one of three essential amino acids (lysine, isoleucine or leucine) was omitted from an infusion of the standard mixture of amino acids. The omission of five other essential amino acids (arginine, histidine, phenylalanine, threonine or valine) from the infusion, or variations in the proportions of leucine, lysine or methionine, had no appreciable effects on wool growth.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 90 , Issue 1 , February 1978 , pp. 173 - 183
Copyright
Copyright © Cambridge University Press 1978

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Block, K. J. & Bolling, D. (1951). The Amino Acid Composition of Proteins and Foods, 2nd ed.Springfield, Illinois: C. C. Thomas.Google Scholar
Block, R. J. & Mitchell, H. H. (1946). The correlation of the amino-acid composition of proteins with their nutritive value. Nutrition Abstracts and Reviews 16, 249–78.Google Scholar
Colebrook, W. F. & Reis, P. J. (1969). Relative value for wool growth and nitrogen retention of several proteins administered as abomasal supplements to sheep. Australian Journal of Biological Sciences 22, 1507–16.CrossRefGoogle Scholar
Downes, A. M., Clarke, W. H. & Dagg, T. C. (1967). Use of radioisotopes in the measurement of wool growth. Atomic Energy in Australia 10 (2), 2–7.Google Scholar
Downes, A. M. & Sharry, L. F. (1971). Measurement of wool growth and its response to nutritional changes. Australian Journal of Biological Sciences 24, 117–30.CrossRefGoogle ScholarPubMed
Fraser, R. D. B., MacRae, T. P. & Rogers, G. E. (1972). Keratins. Their Composition, Structure and Biosynthesis. Springfield, Illinois: C. C. Thomas.Google Scholar
Frenkel, M. J., Gillespie, J. M. & Reis, P. J. (1974). Factors influencing the biosynthesis of the tyrosinerich proteins of wool. Australian Journal of Biological Sciences 27, 31–8.CrossRefGoogle ScholarPubMed
Frenkel, M. J., Gillespie, J. M. & Reis, P. J. (1975). Studies on the inhibition of synthesis of the tyrosinerich proteins of wool. Australian Journal of Biological Sciences 28, 331–8.CrossRefGoogle ScholarPubMed
Harper, A. E., Benevenga, N. J. & Wohlhueter, R. M. (1970). Effects of ingestion of disproportionate amounts of amino acids. Physiological Reviews 50, 428–558.CrossRefGoogle ScholarPubMed
Reis, P. J. (1967). The growth and composition of wool. IV. The differential response of growth and of sulphur content of wool to the level of sulphur-containing amino acids per given abomasum. Australian Journal of Biological Sciences 20, 809–25.CrossRefGoogle Scholar
Reis, P. J. (1969). The growth and composition of wool. V. Stimulation of wool growth by the abomasal administration of varying amounts of casein. Australian Journal of Biological Sciences 22, 745–59.CrossRefGoogle Scholar
Reis, P. J. & Colebrook, W. F. (1972). The utilization of abomasal supplements of proteins and amino acids by sheep with special reference to wool growth. Australian Journal of Biological Sciences 25, 1057–71.CrossRefGoogle ScholarPubMed
Reis, P. J. & Tunks, D. A. (1974). The influence of abomasal supplements of methionine on wool growth of wheat-fed sheep. Australian Journal of Agricultural Research 25, 919–29.CrossRefGoogle Scholar
Reis, P. J. & Tunks, D. A. (1976). The influence of abomasal supplements of zein and some amino acids on wool growth rate and plasma amino acids. Journal of Agricultural Science, Cambridge 86, 475–82.CrossRefGoogle Scholar
Reis, P. J., Tunks, D. A. & Chapman, R. E. (1975). Effects of mimosine, a potential chemical defleecing agent, on wool growth and the skin of sheep. Australian Journal of Biological Sciences 28, 69–84.CrossRefGoogle ScholarPubMed
Reis, P. J., Tunks, D. A. & Downes, A. M. (1973). The influence of abomasal and intravenous supplements of sulphur-containing amino acids on wool growth rate. Australian Journal of Biological Sciences 26, 249–58.CrossRefGoogle ScholarPubMed
Rogers, Q. R. & Egan, A. R. (1975). Amino acid imbalance in the liquid-fed lamb. Australian Journal of Biological Sciences 28, 169–81.CrossRefGoogle ScholarPubMed
Rogers, Q. R. & Leung, P. M. B. (1973). The influence of amino acids on the neuroregulation of food intake. Federation Proceedings 32, 1709–19.Google ScholarPubMed
Spector, W. S. (Ed.) (1956). Handbook of Biologica Data. p. 90. Philadelphia: W. B. Saunders.Google Scholar