Ascariasis and Vitamin A Deficiency in Pigs

Abstract

In 1927 and 1928 Hiraishi published some observations which he had made on Ascariasis in swine in the absence of Vitamin A. He claimed that he had been successful in overcoming the resistance of the pigs to the human strain of Ascaris lumbricoides by lowering the vitamin A content of the diet and that he was able to produce much heavier infestations with Ascaris lumbricoides of swine origion in A-avitaminosed pigs. As all other factors were apparently controlled, he draws the conclusion that vitamin A has a direct bearing on the susceptibility of the pig to infestation with round worms. Unfortunately these publications are not readily available in England and only summaries of results have been available to the present writer. But from the data given and in comparison with the effect of the vitamins on Ascaridia (Ackert et alia, 1929 and 1931 a & b) and on hookworm (Foster & Cort, 1931 and 1932), these conclusions would seem to be justified.