For industrial applications in animal feed, a phytase of interest must be optimally active in the pH range prevalent in the digestive tract. Therefore, the present investigation describes approaches to rationally engineer the pH activity profiles of Aspergillus fumigatus and consensus phytases. Decreasing the negative surface charge of the A. fumigatus Q27L phytase mutant by glycinamidylation o...

Growth and N utilization responses of pigs to Aspergillus niger phytase supplementation of low-protein or high-phytin diets were examined in 2 experiments. In the first experiment, 6 diets arranged in a 3 x 2 factorial with Aspergillus niger phytase at 0, 600, or 1,200 units/kg and dietary protein at 160 or 200 g/kg; and 12 pigs (growth) or 6 pigs (N utilization) per diet were used to test the ...

Objective: A study was conducted to determine the effect of phytase inclusion in broiler breeder diets on fecal and egg characteristics of individually caged females. Materials and Methods: A total of 184 female broiler breeders were fed growing and laying diets containing 0.7% or 2.7% calcium (Ca) and 0.35% or 0.12% available phosphorus (AvP), respectively, with one of four graded levels of ph...

A 360-d study was performed to evaluate the effects of different environmental conditions on storage stability of exogenous phytases. Coated and uncoated products from 3 phytase sources [Ronozyme P (DSM Nutritional Products, Basel, Switzerland), OptiPhos (Phytex LLC, Sheridan, IN), and Phyzyme (Danisco Animal Nutrition, Marlborough, UK)] were stored as pure forms, in a vitamin premix, or in a v...

The aim of this experiment was to compare the responses of young broiler chickens directly with the responses of turkeys to different dietary phytase concentrations. Nine hundred sixty birds (480 female Ross 308 broilers, and 480 female BUT6 turkeys) were reared in 64 floor pens from 0 to 21 d of age. Each species was fed a nutritionally complete (12.79 MJ/kg of AME, 231 g/kg of CP vs. 11.75 MJ...

An experiment was conducted to determine the influence of 2 levels of dietary Ca from limestone and 3 levels of phytase on broiler performance, bone ash, gastrointestinal pH, and apparent ileal digestibility (AID) of Ca, P, and amino acids. Cobb 500 broilers (n = 576) were allowed access to one of 6 corn-soy diets from 0 to 16 d. Experimental diets contained 1.03% or 0.64% Ca from limestone and...

An experiment was conducted to investigate the effect of dietary Ca level on the efficacy of phytase. A total of 288 male Ross × Ross 708 broilers with initial and final BW of 37 and 705 g, respectively, were used in brooder batteries from 0 to 21 d posthatch. Each treatment had 8 replications with 6 broilers/replicate pen. All diets were corn-soybean meal based and formulated to contain 1.26% ...

Three experiments were conducted to evaluate the effectiveness of OptiPhos phytase and citric acid for releasing the P that is not bioavailable in distillers dried grains with solubles (DDGS). The effect of OptiPhos phytate on AME(n) and amino acid digestibility was also determined. New Hampshire x Columbian chicks were fed experimental diets from 8 to 21 d of age. For Experiment 1, a basal P-d...

A six wk feeding experiment was conducted with d-old four hundred broiler chicks (Ven Cobb) to determine the effects of microbial phytase (Allzyme) supplementation in soybean meal based broiler diet containing low phosphorous. These birds were randomly divided into four dietary treatment groups of 100 broilers each. Each treatment group was further sub-divided into five replicates of 25 broiler...

AIMS To isolate, clone and express a novel phytase gene (phy) from Bacillus sp. in Escherichia coli; to recover the active enzyme from inclusion bodies; and to characterize the recombinant phytase. METHODS AND RESULTS The molecular weight of phytase was estimated as 40 kDa on SDS-polyacrylamide gel electrophoresis. A requirement of Ca(2+) ions was found essential both for refolding and activi...