Reproductive disturbances caused by feeding protein-deficient and calcium-deficient rations to breeding pigs

Abstract

(1) Previous work suggests that there are two types or degrees of foetal atrophy. In one case, so far only reported in rats, the atrophy extends to all members of a litter and produces complete sterility. This has been shown to be connected with a pathological condition of the uterine tissues brought about by the absence of vitamin E.Even when vitamin E is in optimum supply, however, there remains a certain amount of foetal degeneration ranging from 7 to 14 per cent, which must arise from causes other than vitamin E starvation.In the second case a partial degree of foetal atrophy has been widely observed by different workers to occur in many different classes of mammals. Average figures for this type quoted for the pig vary from about 2 to about 20 per cent, and the residual degeneration just referred to in the rat appears to be of this nature. The present investigation was carried out to determine the effect on this second type of a deficiency in the diet of protein and of calcium. Evidence is submitted to support the conclusions which follow.(2) Partial foetal atrophy in sows is not due to a deficiency of protein in the ration.(3) Calcium deficiency is not the major factor in producing this type of foetal atrophy though it may be a contributory cause.