Please cite this article as: Taheri HR & Taherkhani S. 2015. Effect of phytase superdoses and citric acid on growth performance, plasma phosphorus and tibia ash in broilers fed canola meal-based diets severely limited in available phosphorus. Poult. Sci. J. 3 (1): 27-36. © 2015 PSJ. All Rights Reserved Abstract Article history: Received: September 29, 2014 Revised: January 29, 2015 Accepted: Ma...

Phytate is the primary storage form of phosphate in plants. Phytases from microbial sources are supplemented to feedstuff of monogastric animals to increase the uptake of phytate phosphorus. The use of microbial phytase is associated with high production cost and also requires special care in feed processing. Expression of phytase in transgenic plants is an alternative approach to the productio...

The phyA gene encoding an extracellular phytase from the thermophilic fungus Thermomyces lanuginosus was cloned and heterologously expressed, and the recombinant gene product was biochemically characterized. The phyA gene encodes a primary translation product (PhyA) of 475 amino acids (aa) which includes a putative signal peptide (23 aa) and propeptide (10 aa). The deduced amino acid sequence o...

Minerals can readily bind to phytic acid and thus have the potential to form mineral±phytate complexes that may be resistant to hydrolysis by phytase activity of animal, plant and microbial origin. In simple solution, at pH 7.0, mineral concentrations from 0.053 mM for Zn up to 4.87 mM for Mg caused a 50% inhibition of phytate-P hydrolysis by microbial phytase. The rank order of mineral potency...

Two experiments were conducted to determine the efficacy of xylanase and phytase supplementation to swine diets based on corn, soybean meal, distillers dried grains with solubles, and wheat bran. In Exp. 1, the apparent ileal digestibility (AID) and the apparent total tract digestibility (ATTD) of energy and nutrients were determined. Eight pigs (initial BW: 24.1 ± 1.9 kg) were surgically fitte...

Phosphorus in runoff from fields where poultry litter is surface-applied is an environmental concern. We investigated the effect of adding phytase and reducing supplemental P in poultry diets and composting poultry manures, with and without Fe and Al amendments, on P in manures, composts, and runoff. We used four diets: normal (no phytase) with 0.4% supplemental P, normal + phytase, phytase + 0...

Sixty-three crossbred barrows averaging 18.7 kg initial BW were used in a 6-wk study of the effects of soaking on the efficacy of supplemental microbial phytase (Natuphos, BASF) in a low-P corn-soybean meal diet. The basal corn-soybean meal diet contained .06% available P, .32% total P, and .55% Ca with no added inorganic P. The basal diet was supplemented with 0, 250, or 500 phytase units (PU)...

An experiment was conducted to determine whether the effects of phytase on amino acid (AA) and energy digestibility in pigs is influenced by the concentration of dietary P. Fourteen barrows (initial BW: 37.8 ± 4.7 kg) were surgically fitted with a T-cannula in the distal ileum and randomly allotted to a replicated 7 × 7 Latin square design with 7 diets and 7 periods. Six diets were formulated t...

Two experiments were conducted with laying hens (Lohmann Brown) in an individual cage system and with single feeding conditions. Experiment 1 (n = 24) was a performance trial (22 to 61 wk) to evaluate phytase effects on performance and nutrient utilization in corn-soybean meal (CSM1) and wheat-soybean meal (WSM1) basal diets (0.12% NPP; 3.1% Ca) supplemented (300 U/kg) with an experimental micr...

Male broilers (n = 416) were used to compare the efficacy of providing dietary phytase either as a commercial supplement or as a recombinant protein in transformed soybean. From 7 to 21 d of age, broilers were fed a basal diet containing 0.20% nonphytate P (nP) with additional supplementation by fungal phytase as Natuphos or as raw transformed soybeans expressing recombinant phytase at 400, 800...