Dietary Zinc and Protein Utilization by Growing Chickens

Abstract

Seventy birds made up of pullets and cockrels of both the RIR and WPR breeds were selected at four weeks of age and fed either a basal ration or the basal ration supplemented with 30, 60 or 90ppm zinc respectively. Breed as well as sex of growers influenced feed consumption. Dietary levels of zinc affected the feed gain ratio regardless of the breed or sex of the growers. Protein digestion was significantly higher in younger birds than in older ones as a result of zinc supplementation, similar differences were observed as a result of breed and sex. Younger birds retained more zinc than the older ones and the possible variations in the activities of enzymes having zinc as co-factor was discussed.