title: Keratinase in starter diets improves growth of broiler chicks.
abstract: The objective of this study was to determine the efficacy of a broad-spectrum protease enzyme, PWD-1 keratinase, upon supplementation to corn-soy starter diets on growth performance of broiler chickens. Three experiments were conducted. In each experiment, 1-d-old broiler chicks were randomly assigned to 24 cage pens of eight birds per pen in a completely randomized design of five experimental treatments and grown to 21 or 26 d of age. Treatments in experiments 1 and 2 were control (C, 21.39% CP), low protein (LP, 18% CP), and LP supplemented with 0.05, 0.1, or 0.15% enzyme preparation (wt/wt). Treatments in experiment 3 were control (C), C+ 0.1% enzyme preparation (C+E) fed starting at either 1 or 5 d of age, LP and LP+ 0.1% enzyme preparation (LP+E). Feeding the LP+E diet produced numerically higher BW at 21 d of age (experiments 1 and 3) and a significantly higher BW at 26 d of age (experiment 2; 1,025 and 1,032 g vs. 965 g for 0.1 and 0.15% vs. LP, respectively, P < 0.05). Feed conversion ratio (FCR) was also improved when chicks were fed the LP+E diet both at 21 (experiment 3) and 26 d of age (experiment 2). In experiment 3, supplementing the C diets with 0.10% enzyme resulted in improvements (P < 0.05) in BW whether the enzyme was supplemented starting at 1 d (767 vs. 695 g for C+E vs. C, respectively) or 5 d of age (764 vs. 695 g for C+E vs. C, respectively). FCR was numerically improved. Furthermore, diets supplemented with the enzyme at any level resulted in reduction of jejunal viscosity at 22 and 27 d of age (P < 0.05). Results of these experiments indicate that the growth of broiler chickens can be significantly improved by dietary supplementation with PWD-1 keratinase.
authors.affiliation: BioResource International, Raleigh, North Carolina 27606, USA. nasser@briworldwide.com
authors.forename: N H
authors.initials: NH
authors.lastname: Odetallah
authors.forename: J J
authors.initials: JJ
authors.lastname: Wang
authors.forename: J D
authors.initials: JD
authors.lastname: Garlich
authors.forename: J C H
authors.initials: JC
authors.lastname: Shih
mesh_terms: D000367:Age Factors; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002645:Chickens / Q000254:growth & development*; D004064:Digestive System / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D010447:Peptide Hydrolases / Q000008:administration & dosage* / Q000494:pharmacology; D011897:Random Allocation; D013025:Glycine max; D014783:Viscosity; D015430:Weight Gain / Q000187:drug effects; D003313:Zea mays
chemical_list: D010447:Peptide Hydrolases; C035855:keratinase