EFEKAT ENZIMA PROTEAZE NA PRINOS I UDEO JESTIVIH PRATEĆIH PROIZVODA KLANJA PILIĆA HIBRIDA MASTER GRIS

Abstract

The effect of supplemental protease (Ronozyme ProAct) in broiler diet on the weights and percentage yields of slaughter by-products of male and female mediumgrowing Master Gris broiler chickens was analysed. Fattening period lasted for 63 days. Broilers were assigned to 3 experimental groups, each consisting of 100 birds. Experimental groups differed in protease levels used in their diets: control broilers (C) received complete feeds (starter, grower and finisher) without supplemental protease; chickens in the experimental group E-I were given a diet containing 0.2% protease and crude protein levels reduced by 4% compared with the control group, whereas experimental E-II broilers were fed a diet supplemented with 0.3% protease and containing crude protein levels reduced by 6% compared with C birds. The analysis of the results showed that feeding treatments had a very small effect on the weights and proportion yields of edible by-products (with difference only in the percentage yield of liver relative to live weight between C and E-I broilers, P<0.05), whereas sex was found to affect almost all slaughter by-products (except abdominal fat weight and the percentage yield of gizzard relative to live weight, P>0.05).