Effect of Urease Immunity upon Rats with Controlled Vitamin A Intakes

Abstract

Summary Two successive experiments, each lasting 8 weeks, were conducted with a total of 100 weanling male rats. Animals actively immunized with crystalline jackbean urease and given either 2.2 or 22.0 I.U of Vit. A daily following a 4-week depletion period grew faster and were more efficient in feed utilization. Both immunizing with urease and increasing the dietary Vit. A level reduced ammonia production and ureolytic activity in the gastrointestinal tract. The evidence indicates that depression of ammonia production and urease activity in the gastrointestinal tract is beneficial to animals fed limited levels of Vit. A.