Efficacy of different commercial phytase enzymes and development of an available phosphorus release curve for Escherichia coli-derived phytases in nursery pigs12

Abstract

In 2 experiments, a total of 184 pigs (PIC, initial BW of 10.3 and 9.7 kg for Exp. 1 and 2, respectively) were used to develop an available P (aP) release curve for commercially available Escherichia coli-derived phytases. In both experiments, pigs were fed a corn-soybean meal basal diet (0.06% aP) and 2 diets with added inorganic P (iP) from monocalcium phosphate (Exp. 1: 0.075 and 0.15% aP; Exp. 2: 0.07 and 0.14% aP) to develop a standard curve. In Exp. 1, 100, 175, 250, or 500 phytase units (FTU)/kg of OptiPhos 2000 or 200, 350, 500, or 1,000 FTU/kg of Phyzyme XP were added to the basal diet. In Exp. 2, 250, 500, 750, or 1,000 FTU/kg of OptiPhos 2000; 500, 1,000, or 1,500 FTU/kg of Phyzyme XP; or 1,850 or 3,700 FTU/kg of Ronozyme P were added to the basal diet. One FTU was defined as the amount of enzyme required to release 1 µmol of iP per minute from sodium phytate at 37°C. For all phytase products, the manufacturer-guaranteed phytase activities were used in diet formulation. All diets were analyzed for phytase activity using both the Phytex and AOAC methods. Pigs were blocked by sex and BW and allotted to individual pens with 8 pens per treatment. Pigs were killed on d 21, and fibulas were collected and analyzed for bone ash. In both experiments, increasing iP improved (linear, P < 0.01) G:F and percentage bone ash. Pigs fed increasing OptiPhos had improved (Exp. 1: linear, P < 0.001; Exp. 2: quadratic, P < 0.001) percentage bone ash, as did pigs fed increasing Phyzyme XP (linear, P < 0.001). In Exp. 2, increasing Ronozyme P improved (quadratic, P < 0.01) percentage bone ash. Using analyzed values from the AOAC method and percentage bone ash as the response variable, an aP release curve was developed for up to 1,000 FTU/kg of E. coli-derived phytases (OptiPhos 2000 and Phyzyme XP) in P-deficient diets. The prediction equation was Y = -0.000000125X(2) + 0.000236X + 0.016, where Y = aP release (%) and X = analyzed phytase (FTU/kg) in the diet.

Effect of formaldehyde inclusion on phytase efficiency in broilers

“…4 Supplied per kilogram of diet: 60 mg of iron (ferrous sulfate); 120 mg of manganese (manganese sulfate and manganous oxide); 100 mg of zinc (zinc oxide); 1 mg of iodine (calcium iodate); 8 mg of copper (copper sulfate); 0.3 mg of selenium (sodium selenite). 5 Supplied per kilogram of diet: 9,600 IU of vitamin A; 3,600 IU of vitamin D 3 ; 18 mg of vitamin E; 15 µg of vitamin B 12 ; 10 mg of riboflavin; 48 mg of niacin; 18 mg of d-pantothenic acid; 2 mg of vitamin K; 1.2 mg of folic acid; 4 mg of vitamin B 6 ; 3 mg of thiamin; 72 µg of d-biotin. 6 Washed sand inclusion was variable depending on enzyme or formaldehyde-based additive diet inclusion.…”

“…Although not having a direct correlation with enzyme activity in vivo, and varying depending on the commercial product supplied, enzyme activity recovered in feed is often used as a direct comparison between different products [5]. Therefore, enzyme activity is often used for enzyme classification.…”

Stability of commercial phytase sources under different environmental conditions1

“…It has been shown that the actual concentration of the product may be greater than the minimum guarantee (Sulabo et al, 2011). Second, it has been shown that there is large analytical variation associated with the laboratory assays utilized to measure phytase activity (Jones et al, 2010). In addition, the differences in the coating methods among the products may have inherently led to differences in assay results.…”

Utilization of Phytase to Overcome Phytic Acid in Broiler Diet

“…Beberapa hasil studi menunjukkan bahwa suplementasi fitase pada ransum dengan kandungan fosfor rendah menghasilkan pengaruh yang positif dalam meningkatkan kinerja pertumbuhan ayam pedaging (Ghazalah et al 2006;Singh 2008;Assuena et al 2009 1) Satu unit aktivitas fitase (FTU) didefinisikan sebagai jumlah enzim yang mampu membebaskan fosfor anorganik 1 μmol per menit dari larutan Na-fitat 0,0051 mol/l pada pH 5,5 dan suhu 37 o C (Jones et al 2010). …”