The composition and digestibility, when fed to pigs, of three grades of meat meal of widely differing fat content

Abstract

The composition, both organic and inorganic, and the digestibility of three grades of meat meal of widely differing fat content have been investigated. Large White hogs were used in the digestion trials.The methods of manufacture of the meat meals have been described. They contained, on the basis of dry matter, 18·8, 11·1 and 3·2 per cent of fat respectively.All three grades had a very high digestibility. The digestion coefficient of the main constituent, namely, the crude protein, ranged from 87·9 per cent in grade C (low fat) to 93·9 per cent in grade B (medium fat), these values comparing satisfactorily with the corresponding value for white fish meal, namely, 90·2 per cent.The pigs digested the fat of the meat meals very efficiently. The fat of the grade A meat meal, forming 18·8 per cent of the dry matter, was digested to the extent of 95·4 per cent.The grade B meat meal (medium fat) was the most digestible of the three grades tested. This is the grade that is marketed for feeding to livestock. The slightly lower digestibility of grade A (high fat) is attributed to the influence of the high fat content in causing a slight lowering of the extent to which the crude protein is digested.The grade C meat meal (low fat) was produced from the grade B by “de-greasing” with petroleum benzine at 300° F. The results suggest that this process may result in a distinct lowering of the digestibility of the meal. The grade C meat meal is the most comparable with white fish meal in both digestible and mineral composition. In comparing the meat meals with white fish meal, however, it must be kept in mind that the former contain a much higher proportion of non-protein nitrogenous material.