Factors affecting the voluntary intake of food by cows

Abstract

There is now considerable evidence suggesting that the voluntary intake of roughages by cows is related directly to their digestibility (Crampton, 1957; Blaxter, Wainman &Wilson, 1961). I n an earlier experiment (Campling, Freer & Balch, 1961) the mean voluntary intake of a medium-quality hay by cows was 21-8 lb daily whereas the cows ate only 10.0 lb of oat straw. It was shown that this difference was directly related to the relative rates of disappearance from the reticulo-rumen of digesta derived from the two foods. The slower rate of disappearance of digesta derived from straw was due both to a slower rate of digestion and to a longer mean time of retention of undigested residues in the alimentary tract.