Influence of superdoses of a novel microbial phytase on growth performance, tibia ash, and gizzard phytate and inositol in young broilers

Abstract

An experiment was conducted to evaluate the influence of a novel microbial phytase on performance, tibia ash, and the content of phytate, phytate esters, and inositol in the gizzard of young broilers. Male Cobb 500 broilers (n = 1,680) were fed 1 of 7 experimental diets: positive control (PC) formulated to meet or exceed nutrient recommendations; PC plus dicalcium phosphate (PC+DCP) formulated to provide Ca and P at 0.10% above the PC; PC plus 500 U/kg of microbial phytase (PC+500); negative control (NC) with Ca and P reduced from the PC by 0.16% and 0.15%, respectively; and the NC plus phytase at 500 (NC+500), 1,000 (NC+1,000), or 1,500 (NC+1,500) U/kg. Diets were fed in crumbled form to 20 birds/pen and 12 replicate pens/diet from d 0 to 21. On d 21, 4 birds/pen were euthanized for collection of right tibias and gizzard digesta for determination of tibia ash and gizzard phytate. In general, broilers fed the NC diet had reduced (P ≤ 0.05) feed intake and BW gain compared with broilers fed diets supplemented with phytase, but not different than the PC or PC+DCP. Phytase supplementation in the NC diet improved (P ≤ 0.05) BW gain comparable with or above that of the PC. Feed conversion ratio was improved in broilers fed the NC+1,000 or NC+1,500 compared with broilers fed all other diets. Tibia ash was reduced (P ≤ 0.05) in broilers fed the NC compared with broilers fed all other diets, and phytase supplementation improved tibia ash comparable with the PC. Phytase supplementation reduced (P ≤ 0.05) phytate (inositol hexa-phosphate) concentration in the gizzard. Inositol concentration in the gizzard was higher (P ≤ 0.05) in birds fed NC+1,000 or NC+1,500 compared with all other diets and this was correlated with growth performance (P ≤ 0.05) rather than tibia ash (P > 0.05). Improvements in feed conversion ratio associated with superdoses of phytase may be attributed to phytate destruction and the provision of inositol.

Influence of Microbial Phytase on Tibia Characteristics and Biochemistry in Blood Serum of Broiler Chickens

“…The highest tibia ash were recorded in birds feed on the high phytase supplementation at T4 (1000FTU/kg). These results were similar with other reports Yan et al, (2000), Viveros et al, (2002), Shirley and Edwards (2003), Saima et al, (2009) andwalk et al, (2014). The data revealed that application of phytase enzyme during summer season was combination showed significant difference (P<0.05) effect tibia characteristics parameters, dry ash (% of live wt.…”

Effects of a rice diet and phytase addition on growth performance, tissue weights, phosphorus and nitrogen retention, and on liver threonine dehydrogenase, malic enzyme and fatty acid synthase activities in broiler chicks

“…Walk et al . () reported that inositol concentration in the gizzard was increased with phytase supplementation. Inositol addition to broiler diet resulted in increased BWG and feed conversion ratio, but these actions were inconsistent and depended on the calcium and phosphorus levels in the diet, presence of phytase and age of the bird (Zyla et al .…”

Influence of partial replacement of ground wheat with whole wheat and exogenous enzyme supplementation on growth performance, nutrient digestibility and energy utilization in young broilers

“…It has been suggested that NSP degradation in poultry mainly occurs in the crop and gizzard (Pettersson and Aman, 1989). In a recent study, Walk et al (2014) showed that phytase inclusion into a broiler diet resulted in almost complete hydrolysis of myoinositol hexaphosphate and an increase in inositol concentration in the gizzard, even before digesta reach duodenum. It has been shown that gizzard pH is relatively higher with pelleted diets when compared to mash diets (Engberg et al, 2002;Huang et al, 2006;Frikha et al, 2009), due mainly to the higher FI and possibly lower hydrochloric acid secretion (Svihus, 2011).…”