Effect of phytase supplentation to weat-soybean diets with different nonphytate phosphorus content on the productivity, protein, phosphorus and calcium utilization, tibia ash content and histological structure in broiler chickens at an early age
2008
Georgieva, V., Thracian University, Stara Zagora (Bulgaria) | Chobanova, S., Thracian University, Stara Zagora (Bulgaria) | Ganchev, G., Thracian University, Stara Zagora (Bulgaria) | Dimitrov, D., Thracian University, Stara Zagora (Bulgaria)
An 11-day experiment with 200 one-day old male broiler chickens (Ross 308), divided into 5 groups (each one repeated 4 times), was performed in order to determine the effect of phytase supplementation as Ronozyme P at 1000 PU/kg to wheat-soybean diets with a different nonphytate phosphorus (nPP) content ѓ\{ from 0.45% to 0.30%, on the productivity, protein, phosphorus and calcium utilization, tibia ash content and tibia histological structure in broiler chickens. The chickens from the control group were fed on a diet with 0.45% nPP but without phytase supplementation. The results of the experiment showed that the live body weight and feed conversion ratio in the 11-day-old broiler chickens fed on wheat-soybean diets supplemented with phytase but with different nPP level (0.45-0.30%), did not differ significantly from the respective indices in the broilers fed on a non-supplemented diet at a normal (0.45%) nPP level. The effect of phytase supplementation was the strongest positive and statistically significant vs. the other groups with regard to protein and phosphorus (P) utilization in the diets with the lowest nPP level (0.30%) and to calcium (Ca) in the diets with 0.35% and 0.30% nPP. The phytase supplementation of wheat-soybean diets containing 0.40 % and 0.35% nPP improved the tibia ash content and the proportion of P in it compared to those in the control chickens. The light microscopy of histological preparations from all 5 experimental groups showed that the general histological structure of bones was preserved in all chickens. The microstructural changes in the tibias of chickens from groups IV and V showed that there were initial structural changes in diaphyseal compacta evidencing an active calcium-phosphorus remodeling.
显示更多 [+] 显示较少 [-]