The Influence of Pasture on the Vitamin A and Carotene in the Milk of Cows

Abstract

30 SYMPOSIUM PROCEEDINGS I957constituent more directly responsible. For instance, there is evidence to suggest that a low level of amino-acids in the digesta of the small intestine may depress the absorption of magnesium from that organ (McCance & Widdowson, 1944), and this level could well be related to the type of fermentation proceeding in the rumen. This brief account of our investigation of the pattern of rumen fermentation and the metabolism of the cow has indicated the special features and problems connected with the feeding of spring grass, but clearly much further study along these lines is required.We should like to record our appreciation of the constant advice and criticism of Dr S. J. Rowland throughout the course of our work. Many of the experiments reported have been done in association with Dr C. C. Balch and we are grateful to him, and to Dr A. T. Cowie for establishing the rumen and intestinal fistulas in the cows and sheep.