Nutritive Value of Pasture. X. The Utilisation of Young Grass by Swine

Abstract

SummaryIn this communication are brought forward the results of digestion trials designed to discover the degree to which pigs are able to digest and utilise young grass. Three digestion trials have been carried out. In the first trial, the digestibility of a basal ration composed of equal parts of maize meal and coarse middlings was determined. In the following two periods, the amount of basal food was cut down to an appropriate level and definite weights of the grass to be tested were added. In period 2, very short, leafy grass, containing, on the basis of dry matter, 26·04 per cent, of crude protein and 16·73 per cent. of crude fibre, was used, whilst somewhat older grass, containing 16·76 and 19·42 per cent. crude protein and fibre respectively, was fed in the third period.It was found that the Large White hogs, which averaged about 195 lb. live-weight during the carrying out of the grass periods of feeding, were unable, with the exception of the fibrous component, to digest the constituents of even young grass with anything like the same degree of efficiency as they displayed in the digestion of the basal ration of middlings and maize meal. The constituents of the older grass, with the exception of the crude protein, were not markedly less digestible than those of the very young grass. The relative values of the pasturage and mixed meal are best brought out by the data for the digestion coefficients of the total organic matter; the pigs were able to digest about 85 per cent. of the organic matter of the meal, and only 60–62 per cent. of that contained in the grass.