RESPONSE OF BROILER CHICKS TO GROWTH PROMOTERS DURING DIFFERENT GROWTH PERIODS

 A.A. Ghazalah, A.S.Abd El-Hakim, Amira.M. Refaie

Abstract: A total number of 420 unsexed day old Arbor Acres broiler chicks were used in two experiments. The birds were randomly distributed into 14 treatments of 30 chicks each. Two kinds of commercial probiotics (Avi-Bac and Zimoferment) were used at the recommended level and supplemented to chick's diets during starter (7-21d), starter-grower (7-35d) and starter-grower-finisher (7-49d) periods  (Experiment 1). In the second experiment, two types of natural growth promoters (Fish soluble extract and Hot pepper) each at 1% level were also supplemented into chick's diet during the same periods as previously mentioned in the first experiment. Two control diets were used for comparison, one of them based on all plant protein and the other one contained animal protein, both were formulated without supplementation. The chicks were fed a corn-soy diet containing 22.9% CP and 3138 kcal ME/Kg for the first 7 days. All the experimental diets were formulated to be isonutritive value (22, 20 and 18% CP) , and (3000,3000 and3100 kcal ME/kg) for starter, grower and finisher periods, respectively .The results obtained indicated that during starter-grower period        (7-35d), it is preferable to use either Avi-Bac as commercial probiotic or hot pepper as natural growth promoter in broiler diet. While, during overall period (7-49d), fish soluble extract as natural growth promoter is superior. By comparison, the use of commercial probiotics particularly Zimoferment and Avi-Bac in broiler diets is better than fish soluble and hot pepper as natural growth promoters. This may be attributed to the direct and effective role of live microorganisms, enzymes and other biological components in such probiotics. These findings were also attained by the organoleptic properties of meat, as well as the economical evaluation.