Effect of High Phytase Inclusion Rates on Performance of Broilers Fed Diets Not Severely Limited in Available Phosphorus

Abstract

Phytate is not only an unavailable source of phosphorus (P) for broilers but it also acts as an anti-nutrient, reducing protein and mineral absorption, increasing endogenous losses and reducing broiler performance. The objective of this study was to investigate the anti-nutritional effects of phytate by including high levels of phytase in diets not severely limited in available P. A total of 768 male Arbor Acres broilers were distributed in six treatments of eight replicate pens of 16 birds each consisting of a positive control diet (PC), positive control with 500 FTU/kg phytase, negative control (NC) diet with lower available P and calcium (Ca) levels and the same NC diet with 500, 1,000 or 1,500 FTU/kg phytase. Body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR) and mortality were determined at 21 and 35 d of age while foot ash was determined in four birds per pen at 21 d of age. FI, FCR and foot ash where not affected by the lower mineral diets at 21 d of age nor by the enzyme inclusion but broilers fed lower Ca and available P diets had lower BWG. At 35 d of age no difference was observed between broilers fed the positive or NC diets but broilers fed 500, 1,000 and 1,500 FTU/kg on top of the NC diet had better FCR than broilers fed the positive control diet. When compared to birds fed a diet adequate in P, birds fed the same diet included with 500, 1,000 and 1,500 FTU/kg of phytase in marginally deficient available P and Ca diets had an improvement of performance. These results support the concept that hydrolysing phytate and reducing the anti-nutritional effects of phytate improves bird performance on marginally deficient diets that were not covering the P requirement of birds.

Evaluation of the Combined Use of Saccharomyces Cerevisiae and Aspergillus Oryzae with Phytase Fermentation Products on Growth, Inflammatory, and Intestinal Morphology in Broilers

“…From the results, the addition of SCFP and AOFP did not improve body weight, feed consumption, weight gain, and FCR. However, Santos et al [22] reported that phytase addition (500 FTU/kg) improved the body weight gain of 1-21 day-old broilers, but did not improve the body weight gain and FCR in 22-35 day-old broilers. Mountzouris et al [23] pointed out that S. cerevisiae powder (50 mg (10 9 CFU)/kg diet) addition did not enhance the growth performance.…”

Effect of increasing supplemental phytase concentration in diets fed to Hubbard × Cobb 500 male broilers from 1 to 42 days of age

“…Data are limited on the effects of feeding super-dosing concentrations of phytase on growth performance and carcass characteristics of broilers [11,12]. The current study examined the effects of supplementing increasing levels of phytase on growth performance and processing parameters in a commercial broiler diet.…”

Optimization of the conditions for rice bran phytate degradation by their own phytases

“…The existing phytase within the rice bran improves phytate phosphorus utilization [29] can be a reason for general phytase activity increase with the increase in rice bran concentrations. Addition of phytase to diets containing rice bran definitely improved further [30].…”

“…The growth rate increased by the addition of phytase in duck diet containing 20% rice bran [18,20]. Phytase hydrolyzes the phytate molecule, discharging P and in the meantime decreasing the concentration and in this way the counter nutritious impacts of phytate [29]. Phytase (500 unit/kg) addition to broilers diets based on corn, wheat, or barely increased apparent metabolizable energy in corn diets [30].…”