Evaluation of Microbial Phytase in Broiler Diets

Abstract

Two trials were conducted to evaluate the efficacy of a new microbial phytase (Phyzyme XP) for broiler chicks. Trial 1 used 192 8-d-old male broilers in a 14-d trial to assess growth and nutrient utilization. Dietary treatments (221.9 g/kg CP) included a positive control [5.0 g/kg nonphytate P (NPP)], negative control (1.2 g/kg NPP), and negative control plus 500 or 1,000 phytase units/kg of diet. Phytase addition increased weight gain, feed intake, feed efficiency, and tibia and toe ash (linear, P < 0.01) with tibia ash also responding quadratically (P < 0.05). Apparent ileal digestibility of P (linear and quadratic, P < 0.05), tryptophan, and valine (linear, P < 0.05) also increased. Linear and quadratic responses were observed for retention of DM, nitrogen, P, and several amino acids (P < 0.05) with added phytase. Trial 2 utilized 576 1-d-old male broilers over a 42-d period to evaluate growth performance. Diets were formulated for starter (222.7 g/kg CP) and grower (201.5 g/kg CP) phases and included a positive control (starter and grower, 5.0 and 3.8 g/kg NPP, respectively); negative control (starter and grower, 2.4 and 1.8 g/kg NPP, respectively); negative control plus 500, 750, or 1,000 phytase units/kg; and negative control plus 500 phytase units/kg of Natuphos phytase. Phytase increased weight gain and feed intake (starter, grower, overall) as well as feed efficiency during the starter period (linear, P < 0.05). Feed intake was also improved during the grower period and overall (quadratic, P < 0.05). Tibia and toe ash of birds fed for the first 21 d increased (linear, P < 0.05) with tibia ash also increasing quadratically (P < 0.05). Overall, tibia and toe ash were improved due to phytase addition (linear and quadratic, P < 0.05). In conclusion, this microbial phytase, derived from Escherichia coli and expressed in Schizosaccaromyces pombe, elicited improved growth performance, bone mineralization, and P utilization in broiler chicks.

Increasing zinc levels in phytase-supplemented diets improves the performance and nutrient utilization of broiler chickens

“…As feed intake of birds was unaffected by phytase supplementation, the improved BWG of the same group of birds could be interpreted as being a consequence of the release of phytate-bound minerals and other nutrients by phytase. The beneficial effect of phytase on BWG has also been reported in previous studies (Dilger et al, 2004;Akter et al, 2017). The lack of response to phytase on FCR is in agreement with Roy et al (2014).…”

Diet supplementation with phytase on performance of broiler chickens

“…For the whole rearing period, feed conversion of birds of negative control group 2 was statistically inferior (P<0.05) than those of positive control and negative control 2 + 500 uft. Dilger et al (2004) and Lan et al (2002) evaluated the performance of broilers fed diets containing different levels of the enzyme phytase and low levels of Pd and also observed that the addition of this enzyme provided better performance to birds, when compared with those which received diets without the inclusion of the enzyme. Fukayama et al (2008) observed that the addition of phytase in all the levels utilized (500, 700 and 1,000 uft/kg of the diet) improved the performance of 1-to 20-day old broilers.…”

“…Research has shown that the performance of broilers fed with different levels of inclusion of phytase and low levels of available P in the diets can improve with the addition of the enzyme (Dilger et al, 2004;Santos et al, 2005;Fukayama et al, 2008). However, other researchers did not observe beneficial effect on broiler performance with the addition of phytase in the diets (Lima et al, 2002;Assuena et al, 2007).…”

A review on role of exogenous enzyme supplementation in poultry<br>production

“…Several research studies which have reported the effect of phytase on digestibility of amino acids has been determined. In these studies, the inert markers selected include chromic oxide (Kornegay et al, 1999;Zhang et al, 1999;Camden et al, 2001;Dilger et al, 2004;Onyango et al, 2005), acid insoluble ash and titanium oxide (Rutherfurd et al, 2002;Ravindran et al, 2006). It was reported that effect is greater when acid insoluble ash or titanium oxide were used as dietary markers in comparison to chromic oxide.…”