Philippine E-Journals

Efficacy Of Escherichia Coli And Aspergillus Derived Phytases On Performance And Carcass Yield Of Broilers Fed Reduced Phosphorus Diets

Carmencita D. Mateo | Mylen S. Billena

Discipline: Veterinary Medicine, Animal Science

 

Abstract:

A 42-day feeding trial was conducted to evaluate the efficacy of an Escherichia coli derived phytase (ECP) and a commercially available Aspergillus derived fungal phytase (FP) on the growth performance and carcass yield of 480 male broiler chicks fed corn-soybean meal based diets that were adequate or reduced in phosphorus (P). The six diets consisted of: 1) positive control, adequate in all nutrients required by broilers in the starter, grower, and finisher phases; 2) negative control which was diet 1 with available P (AP) reduced by 0.10% and Ca by 0.21%; 3), 4), and 5) diet 1 with AP reduced by 0.10, 0.13, and 0.20% with the inclusion of 250, 500, and 1000 FTU/kg ECP respectively, and; 6) diet 1 with AP reduced by 0.10% and 500 FTU/kg FP. During the starter phase (1-14 days), broilers fed diets with ECP at all levels had significantly better weight gain and feed:gain than birds fed the fungal derived phytase or those fed the positive and negative control diets. Slightly decreasing dietary P and Ca (diet 2) did not reduce (P>0.05) growth performance, carcass yield and bone ash. No significant differences were noted in the overall performance of birds among treatments. The E. coli derived phytase at 1000 FTU/kg effectively replaced up to 0.20% AP while FP at 500 FTU/kg replaced 0.10% AP in corn-soybean meal based diets reduced in P. At the same phytase units (500 FTU/kg), the E. coli phytase released 30% more (0.13 vs. 0.10%) AP relative to that released by the fungal derived phytase without negative impact on overall performance, carcass yield, and bone mineralization in broilers.