Zinc Deficiency Syndrome in the Young Lamb

Abstract

Eighteen lambs averaging 13.5 kg were divided into 6 comparable groups and fed the following diets: basal, basal + 2% polyethylene, basal + 0.61% phytic acid, basal + 0.61% phytic acid + 2% polyethylene, basal + 100 mg zinc/kg, and basal + 100 mg zinc/kg + 2% polyethylene. The basal diet (2.7 mg zinc/kg) was composed of the following: (in per cent) egg whites, 15.00; cellulose, 18.00; glucose monohydrate, 27.02; starch, 27.02; corn oil, 3.00; minerals and vitamins. The animals fed the diets not supplemented with zinc exhibited the following symptoms: anorexia; depraved appetite (eating wool); reduced growth; reduced feed efficiency; loose wool; swollen hocks; red, wrinkled skin; and open lesions of the skin above the hoof and around the eyes. Tissue changes characteristic of the deficiency were decreased tissue zinc and parakeratotic lesions of the skin. Blood changes typical of the deficient animals were decreased serum zinc, decreased serum albumin and increased globulin levels. Excessive salivation, increased rumen propionic acid production and a corresponding reduction in butyric acid were also associated with the deficiency. The zinc deficiency appeared to be less severe in the lambs fed phytic acid. Feeding 100 mg zinc/kg of the basal diet to deficient lambs for 5 weeks completely alleviated most of the deficiency symptoms. The polyethylene added to the diet had little or no effect on performance but appeared to stimulate rumination.