Zinc Requirement of the Growing Pig Fed Isolated Soybean Protein Semi-Purified Rations

Abstract

Three experiments were conducted with 114 three-week-old pigs to determine the zinc requirement of the growing pig when isolated soybean protein was fed in the ration and to characterize the zinc deficiency syndrome. The results show that zinc was a necessary constituent of the ration of the growing pig. The dietary zinc requirement of the growing pig fed semi-purified rations containing isolated soybean protein was 46 p.p.m. of the total ration in two of the three experiments. Pigs fed a ration deficient in zinc showed the following symptoms in order of appearance: decreased feed and water intake, retarded growth, scours, parakeratosis, rough hair coat, slight fading in color of hair coat, loss of hair, listlessness, a stance with all four feet together and eventually death. The parakeratotic lesions first appeared on the underneath side around the sheath and between the front and rear legs and spread to all parts of the body as the deficiency became more acute. The dietary zinc requirement of the pig was lower when casein was substituted pound-for-pound for isolated soybean protein. Addition of 50 p.p.m. of zinc as zinc oxide resulted in marked improvement of all zinc deficiency conditions; additions of citric acid, thiamine, benadryl, sodium formate-acetic acid mixture, or a mixture of calcium acetate and acetic acid were without effect. Copyright © . .