Author
PUTTRESS, J - UNIVERSITY OF DELAWARE | |
SAYLOR, W - UNIVERSITY OF DELAWARE | |
ANGEL, R - UNIVERSITY OF MARYLAND | |
Mitchell, Alva | |
PERSIA, M - UNIVERSITY OF DELAWARE |
Submitted to: Poultry Science
Publication Type: Abstract Only Publication Acceptance Date: 5/3/2007 Publication Date: 7/21/2007 Citation: Puttress, J., Saylor, W.W., Angel, R., Mitchell, A.D., Persia, M.E. 2007. Effects of mega doses of phytase on broiler chick body composition [abstract]. Poultry Science. Interpretive Summary: Technical Abstract: Phytate is found in seed-based feedstuffs and can bind, among others, Ca, trace minerals and possibly starch and protein reducing bioavailability of these nutrients. New evidence suggests that phytate has additional antinutrient properties. Phytase hydrolyzes P bound to phytate increasing phytate P utilization and reducing the antinutritional effects of phytate. An experiment was conducted to determine the effects of mega doses of phytase on body composition of chicks fed adequate nonphytate P (nPP). There were five experimental treatments including a control diet ( 0.45% nPP) and the same diet supplemented with 500, 7500 and 15000 FTU of OptiPhos (an E. coli phytase; EP), and 15000 FTU of Ronozyme (a fungal phytase; FP). Each treatment was fed to eight replicate groups of eight male Ross 308 chicks from 8 d to 22 d. On d 22, the chicks were euthanized and frozen for dual energy X-ray absorptiometry (DXA) scanning before being ground for wet chemistry body composition analysis. Ground carcass samples were lyophilized and freeze ground for crude protein, crude fat, and ash determination. Phytase supplementation did not affect DXA lean or fat tissue accumulation, but all levels of phytase increased body mineral content over the control diet ( 10.11 to 10.60 g/chick v. 8.74 g/chick; P = 0.0007). Wet chemistry analysis showed increased crude protein of carcasses from chicks supplemented with 15000 FTU of FP compared to 15000 FTU of EP (338 v. 285 g protein/chick; P = 0.0097). Total carcass crude fat was increased in birds fed 15000 FTU of phytase compared to all other treatments (167 and 168 v. 151 to 155 g fat/chick; P=0.0024). Supplementation of birds with 7500 FTU of EP resulted in increased total carcass ash compared to birds supplemented with either 500 FTU of EP or 15000 FTU of PF ( 53.5 g ash/chick v. 46.1 and 44.0 g ash/chick; P = 0.0459). Supplementation of broiler diets with mega doses of phytase can alter chick body composition of birds fed adequate dietary nPP. |