title: Microbial phytase improves amino acid utilization in young chicks fed diets based on soybean meal but not diets based on peanut meal.
abstract: Studies were conducted to evaluate the ability of supplemental microbial phytase to improve performance of young chicks fed phytate-containing, amino acid-deficient diets. Diets based on corn and peanut meal or soybean meal (SBM) and dextrose were fed to young chicks housed in battery cages for 10- and 13-d experimental periods. Assays were designed to evaluate phytase supplementation of both amino acid-deficient and amino acid-adequate diets. Weight gain, feed intake, and gain:feed values of chicks increased (P < 0.05) when deficient amino acids were serially supplemented to either the corn-peanut meal or SBM-dextrose diets. Phytase supplementation (600 and 1,200 U/kg) to the corn-peanut meal diet resulted in no significant differences in weight gain, feed intake, or gain:feed values of chicks when the diet was either deficient or adequate in amino acids. However, phytase supplementation (1,200 U/kg) produced significant increases (P < 0.05) in gain:feed values, but not weight gain, of chicks when they were fed the amino acid-deficient, but not the amino acid-adequate, SBM-dextrose diet. This gain:feed response to phytase supplementation of the amino acid-deficient SBM-dextrose diet occurred in both crossbred (New Hampshire x Columbian) and commercial (Ross x Hubbard) chicks. A digestibility assay was also performed using cecectomized roosters fed dehulled SBM containing three levels of phytase (0, 600, and 1,200 U/kg). When averaged across nine essential amino acids and cystine, true amino acid digestibility (TAAD) values were increased by approximately 2% when 1,200 U/kg phytase was included with SBM and administered to cecectomized roosters. However, neither TAAD values nor TMEn were significantly improved by the phytase addition.
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
authors.forename: R R
authors.initials: RR
authors.lastname: Biehl
authors.forename: D H
authors.initials: DH
authors.lastname: Baker
mesh_terms: D010832:6-Phytase / Q000008:administration & dosage / Q000494:pharmacology*; D000596:Amino Acids / Q000172:deficiency / Q000378:metabolism*; D000704:Analysis of Variance; D000821:Animal Feed; D000818:Animals; D010367:Arachis; D001419:Bacteria; D002432:Cecum / Q000502:physiology; D002645:Chickens; D004063:Digestion; D005260:Female; D005527:Food, Fortified; D008297:Male; D013025:Glycine max; D015430:Weight Gain
chemical_list: D000596:Amino Acids; D010832:6-Phytase