The Yeast Production System in Which Escherichia coli Phytase is Expressed May Affect Growth Performance, Bone Ash, and Nutrient Use in Broiler Chicks

Abstract

The efficacy of three Escherichia coli-derived phytase preparations on the performance and nutrient utilization of broiler chicks was evaluated. Two hundred sixteen 7-d-old male broiler chicks were grouped by weight into 6 blocks of 6 cages with 6 birds per cage. Six corn-soybean meal-based diets were randomly assigned to cages within each block. The 6 diets were adequate P, very low P, and low P and contained (g of P/kg of diet) 7.7, 4.0, and 5.1, respectively; and low-P diet plus phytase preparation A, B, or C at 1,000 units/kg of feed. All 3 phytase preparations were produced in different yeast production systems with slightly different glycosylation patterns. Preparation A was produced in Pichia pastoris, B in Schizosaccharomyces pombe, and C in Saccharomyces cerevisiae. The chicks were fed the experimental diets from 8 to 22 d of age. Excreta samples were collected between 17 and 21 d of age. At the end of the study, blood was collected, chicks were killed, and tibiae were removed from 3 birds per cage. Weight gain, feed intake, and feed efficiency among the 3 phytase preparations did not differ, although only phytase A diet outperformed (P < 0.05) the low-P diet in terms of weight gain and feed efficiency. All 3 phytase diets outperformed (P < 0.05) the low-P diet in bone mineral content, density, strength, percentage ash, P retention, and serum P levels. Phytase B diet outperformed the adequate-P diet in bone strength. All 3 preparations increased (P < 0.05) Ca retention with phytase B or C showing a better retention of Ca than phytase A. All 3 phytase preparations showed similar P use as indicated by BW gain and tibia bone characteristics.

Phytase activity along the digestive tract of the broiler chick: A comparative study of an Escherichia coli-derived and Peniophora lycii phytase

“…The pH range in the crop, proventriculus and gizzard, or ileum of poultry is 4-5, 2.5 or 6-7, respectively (Simon and Igbasan 2002). The pH optima for phytase from P. lycii is 4.0-4.5 (Augspurger et al 2003) and that from E. coli is 4.5 (Onyango et al 2004). Both E. coli and P. lycii phytases would be more active in the crop than in the proventriculus and gizzard of the chicken.…”

Effects of dietary supplementation of exogenous multi-enzyme mixture containing carbohydrases and phytase on growth performance, energy and nutrient digestibility, and selected mucosal gene expression in the small intestine of weanling pigs fed nutrient deficient diets

“…Chromium concentration was determined by digesting samples in concentrated nitric acid and 70% perchloric acid and absorption was measured at 440 nm using a spectrophotometer (Spectronic 21D, Milton Roy Co., Rochester, NY, USA) (Fenton and Fenton 1979). Samples were digested in concentrated nitric acid and 70% perchloric acid to solubilize Ca and P. Total P content was measured by spectrophotometric reading of absorption at 620 nm using a method described by Onyango et al (2004). Concentration of Ca in the supernatant was determined using flame atomic absorption spectrometry (Varian FS240 AA Varian Inc., Palo Alto, CA, USA).…”

Xylanase in diets for growing pigs and broiler chicks

“…Nitrogen was determined using the combustion method (Leco FP analyzer Model 602600, Leco Corp., St. Joseph, MI). Samples were digested in concentrated nitric acid and 70% perchloric acid to solubilize Ca and P. The concentration of P in the supernatant was measured using a kit (Sigma kit # 670, Sigma Diagnostics, Inc., St. Louis, MO) as described by Onyango et al (2004). The Ca content of the supernatant was determined using flame atomic absorption spectrometry (Varian FS240 AA Varian Inc., Palo Alto, CA).…”