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Voluntary intake of food by mature sheep following restricted feeding

Published online by Cambridge University Press:  27 March 2009

D. M. Keenan
Affiliation:
School of Wool and Pastoral Sciences, University of New South Wales
W. R. McManus
Affiliation:
School of Wool and Pastoral Sciences, University of New South Wales
M. Freer
Affiliation:
Division of Plant Industry, CSIRO, Canberra, A.C.T.

Summary

Nine Merino wethers were used in a cross-over experiment to compare the voluntary intake of three diets after a 4-week period in which the intake of the same diets was restricted, either to a level which maintained the live weight and energy status of the sheep, or to one which resulted in losses of 18% and 26% in their live weight and total energy content respectively. The diets were prepared from lucerne hay; chaffed (L), ground and pelleted (P) and pelleted after mixing with ground wheat (W).

The voluntary intake of food increased only slowly during the 4 weeks after restrictions were removed; the total intake of digestible organic matter from diets W, L and P was in the ratio 100:122:146. Differences between diets L and P, but not W, were associated with their rates of disappearance from the rumen. Sheep which had been severely restricted ate less food during the first fortnight and no more during the second fortnight than those which had previously maintained their energy status. The difference in the first fortnight was less for diet P than for diet L. The process of adaptation by the sheep to unrestricted feeding was associated with an increase in the net rate of disappearance of volatile fatty acids from the rumen.

Sheep offered food ad lib. after a period of submaintenance feeding gained more weight than sheep which had previously been fed to maintain weight and this increase was greater with diet P than with diet L. However, the differences in live-weight change consisted largely of water in the gut and did not result from a relative increase in the voluntary intake of food or in the efficiency of energy utilization.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1970

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References

REFERENCES

Baile, C. A. & Mayer, J. (1968). Effects of intravenous versus intraruminal injection of acetate on feed intake of goats. J. Dairy Sci. 51, 1490–4.CrossRefGoogle ScholarPubMed
Balch, C. C. (1950). Factors affecting the utilization of food by dairy cows. 1. The rate of passage of food through the digestive tract. Br. J. Nutr. 4, 361–88.CrossRefGoogle Scholar
Barker, S. B. & Summerson, W. H. (1941). The colorimetric determination of lactic acid in biological material. J. biol Chem. 138, 535–54.CrossRefGoogle Scholar
Butterfield, R. M. (1966). The effect of nutritional stress and recovery on the body composition of cattle. Res. vet. Sci. 7, 168–79.CrossRefGoogle ScholarPubMed
Castle, E. J. (1956). The rate of passage of foodstuffs through the alimentary tract of the goat. 1. Studies on adult animals fed on hay and concentrates. Br. J. Nulr. 10, 1523.CrossRefGoogle ScholarPubMed
Draper, N. R. & Smith, H. (1966). In Applied Regression Analysis. New York: Wiley.Google Scholar
Erwin, E. S., Marco, G. J. & Emery, E. M. (1961). Volatile fatty acid analyses of blood and rumen fluid by gas chromatography. J. Dairy Sci. 44, 1768–71.CrossRefGoogle Scholar
Hebblethwaite, P. & Hepherd, R. Q. (1956). A detailed procedure of testing for hammer mills and other farm grinding mills. Tech. Mem. N.I.A.E. No. 129.Google Scholar
Hungate, R. E., Dougherty, R. W., Bryant, M. P. ' Cello, R. M. (1952). Microbiological and physiological changes associated with acute indigestion in sheep. Cornell Vet. 42, 423–19.Google ScholarPubMed
Hydén, S. (1961). Determination of the amount of fluid in the retioulo-rumen of the sheep and its rate of passage to the omasum. K. Lantbr Högsk. Annlr. 27, 5179.Google Scholar
Keenan, D. M., McManus, W. R. & Freer, M. (1969). Changes in the body composition and efficiency of mature sheep during loss and regain of live weight. J. agric. Sci., Camb. 72, 139–47.CrossRefGoogle Scholar
McClymont, G. L.(1951). Volatile fatty acid metabolism of ruminants, with particular reference to the lactating bovine mammary gland and the composition of milk fat. Aust. J. agric. Res. 2, 158–79.CrossRefGoogle Scholar
Meyer, J. H. & Clawson, W. J. (1964). Undernutrition and subsequent realimentation in rats and sheep. J. Anim. Sci. 23, 214–24.CrossRefGoogle Scholar
Reid, R. L., Hogan, J. P. & Briggs, P. K. (1957). The effect of diet on individual volatile fatty acids in the rumen of the sheep, with particular reference to the effect of low rumen pH and adaptation on high starch diets. Aust. J. agric. Res. 8, 691710.CrossRefGoogle Scholar
Wilson, P. N. & Osbourn, D. F. (1960). Compensatory growth after undernutrition in mammals and birds. Biol. Rev. 35, 324–63.CrossRefGoogle ScholarPubMed
Winchester, C. F. & Howe, P. E. (1955). Relative effects of continuous and interrupted growth on beef steers. Tech. Bull. U.S.D.A. No. 1108.Google Scholar