EFFECTS OF DIETARY ENZYME SUPPLEMENTATION WITH SOME PLANT PROTEIN LEVELS ON THE PERFORMANCE OF BROILER CHICKS | ||
| Journal of Animal and Poultry Production | ||
| Article 2, Volume 28, Issue 10, October 2003, Pages 7139-7155 PDF (4.92 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jappmu.2003.245273 | ||
| Authors | ||
| Kh. EI. Sherif,; M. H. Rabie; F. S. A. Ismail; A. H. Raya | ||
| Poultry Production Department, Faculty of Agriculture, Mansoura University, Egypt | ||
| Abstract | ||
| The present study was carried out to evaluate the response of broiler chickens fed diets with different crude protein levels to dietary enzyme (Allzyme Vegpro) supplementation. Day-old unsexed broiler chicks were fed on a commercia! starter diet (contained 22% crude protein and metabolizable energy, ME, 'of about 3100 kcal/kg) up to 17 days of age. Then, two hundred and fifty-two birds were randomly distributed into six equal experimental groups, each with six equal replicate groups, kept at the rearing batteries and fed ad libitum their respectiye mash experimental diets. Six iso-energetic diets (ME of about 3000 kcallkg) contai~ed three levels of crude protein (20,18 or 16%) and two levels of enzyme supplement~tion (0.0 or 1.5 g/kg diet) were formulated and used from 17 to 45 days of age. The ~riteria of response were live body weight, daily weight gain, feed intake, protein intake and feed conversion. Total mortality and economic efficiency of feeding were also determined. Nutrient digestbilities of the experimental diets were measured when the birds were 5 weeks of age. At the termination of the study, certain parameters of carcass traits and some blood constituents (plasma levels of glucose, total protein, total lipids and cholesterol as well as activities of plasma transaminases: AST and AL T) were quantified. The results obtained, for the whole experimental period, can be summarized as follows: Regardless of enzyme supplementation, decreasing dietary crude protein (CP) level from 20 to 16% adversely affected (P$0.01) live body weight, body weight gain, daily protein intake, feed conversion ratio and economic efficiency of feeding. Also, decreasing dietary CP level significantly (P$0.01) increased abdominal fat percentage. However, dietary CP level had no significant effects on mortality of chicks, daily feed intake, nutrient digestibility, tested blood parameters or carcass traits. Enzyme supplementation, regardless of dietary CP level, significantly improved (P$0.01) the feed conversion ratio of broiler chicks during the whole period of study. All other criteria measured were not significantly (P>0.05) influenced by the enzyme supplementation. Also, the interactions between dietary CP level and enzyme supplementation were not significant (P>0.05) for all studied criteria. Under the conditions of this study, economically, it was concluded that a level of 20% CP with or without enzyme supplementation is the optimal dietary protein level in grower broiler diets for maximizing broiler growth performance and optimizing the efficiency of feed utilization. The diet should also be well balanced in all nutrients and its CF' content should provide a balanced pattern of amino acids. | ||
| Keywords | ||
| Allzyme Vegpro; dietary protein level; broiler performance | ||
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