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Pattern of intake of three roughage diets by non-pregnant, non-lactating Scottish Blackface ewes over a long period and the effects of previous nutritional history on current intake

Published online by Cambridge University Press:  02 September 2010

Janet Z. Foot
Affiliation:
Hill Farming Research Organisation, Bush Estate, Penicuik, Midlothian EH26 0PY
A. J. F. Russel
Affiliation:
Hill Farming Research Organisation, Bush Estate, Penicuik, Midlothian EH26 0PY
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Abstract

The voluntary intake of two hays and one dried grass by 48 mature non-pregnant Blackface ewes was measured for 33 weeks. The apparent dry-matter digestibility coefficients of the diets in vitro were 59, 61 and 77% respectively for the hays and the dried grass. At the end of the first phase of the experiment each group of 16 ewes was split into two subgroups of five animals, each of which was subsequently given one of the other diets, and one subgroup of six animals which remained on the same diet. Food intake was measured for a further 8 weeks. Body fat was estimated at intervals from tritiated water space.

The amount of variation in voluntary food intake that could be attributed to variation in live weight and fatness of the animals and in apparent dry-matter digestibility and cell wall constituents of the diet was calculated for various periods.

The range of live weight and fatness increased during the experiment. Initially, and after the change in diets, variation in apparent dry-matter digestibility had an important positive effect on intake, but at the end of the 33-week phase its influence was negligible or, when fat weight was not considered, negative. The negative effect of fat weight on intake increased during the experiment.

Within individual diets during short periods of time (1 to 5 weeks) the highest proportions of the variation in intake that could be attributed to variation in live weight and fatness of the ewes were 50, 94 and 65% respectively for the hays and the dried grass. Taking all three diets together all the variables considered could explain 75% of the variation for a few weeks at a time, but for longer periods seasonal influences, and other factors not included among the independent variables, probably operated.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1978

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References

REFERENCES

Alexander, R. H. and McGowan, M. 1961. A filtration procedure for the in vitro determination of digestibility of herbage. J. Br. Grassld Soc. 16: 275277.CrossRefGoogle Scholar
Baile, C. A. 1971. Control of feed intake and the fat depots. J. Dairy Sci. 54: 564582.CrossRefGoogle Scholar
Bines, J. A., Suzuki, S. and Balch, C. C. 1969. The quantitative significance of long-term regulation of food intake in the cow. Br. J. Nutr. 23: 695704.CrossRefGoogle ScholarPubMed
Blaxter, K. L., Wainman, F. W. and Wilson, R. S. 1961. The regulation of food intake by sheep. Anim. Prod. 3: 5161.Google Scholar
Ferguson, K. A. 1956. The efficiency of wool growth. Proc. Aust. Soc. Anim. Prod. 1: 5862.Google Scholar
Foot, J. Z. 1972. A note on the effect of body condition on the voluntary intake of dried grass wafers by Scottish Blackface ewes. Anim. Prod. 14: 131134.Google Scholar
Foot, J. Z. and Greenhalgh, J. F. D. 1970. The use of deuterium oxide space to determine the amount of body fat in pregnant Blackface ewes. Br. J. Nutr. 24: 815825.CrossRefGoogle ScholarPubMed
Forbes, J. M. 1977. Interrelationship between physical and metabolic control of voluntary food intake in fattening, pregnant and lactating mature sheep: a model. Anim. Prod. 24: 91101.Google Scholar
Gordon, J. G. 1964. Effect of time of year on the roughage intake of housed sheep. Nature, Lond. 204: 798799.CrossRefGoogle ScholarPubMed
Graham, N. McC. 1969. The influence of body weight (fatness) on the energetic efficiency of adult sheep. Aust. J. agric. Res. 20: 375385.Google Scholar
Greenhalgh, J. F. D. and Reid, G. W. 1974. Long- and short-term effects on intake of pelleting a roughage for sheep. Anim. Prod. 19: 7786.Google Scholar
Osbourn, D. F. and Cammell, S. B. 1970. The effect of duration of the period of measurement and changes in condition of the animals upon the measured voluntary intake of forages. A. Rep. Grassld Res. Inst., 1969, p. 75.Google Scholar
Russel, A. J. F., Doney, J. M. and Gunn, R. G. 1969. Subjective assessment of body fat in live sheep. J. agric. Sci., Camb. 72: 451454.CrossRefGoogle Scholar
Schinkel, P. G. 1960. Variation in feed intake as a cause of variation in wool production of grazing sheep. Aust. J. agric. Res. 11: 585594.CrossRefGoogle Scholar
Van soest, P. J. and Wine, R. H. 1967. Use of detergents in the analysis of fibrous feeds. IV. Determination of plant cell-wall constituents. J. Ass. off. agric. Chem. 50: 5055.Google Scholar
Williams, A. J. 1964. The effect of daily photoperiod on wool growth of Merino rams subjected to unrestricted and restricted feeding regimes. Aust. J. exp. Agric. Anim. Husb. 4: 124128.CrossRefGoogle Scholar
Yadava, R. K., Conrad, H. R. and Gilmore, L. O. 1973. Effect of body condition at calving on the feed intake and digestibility of the dairy cow. Indian J. Anim. Sci. 43: 1624.Google Scholar