Research Of Phytase's Effect In Broiler Diets Contained Different Levels Of Phytate Phosphorus

This research focused on the effect of phytase on broiler chicks' growth performance, apparent ileal nutrient digestibility and tibia mineralization in diets contained different levels of phytate phosphorus(PP). The experimental design was a 2 × 2 factorial arrangement, including 2 phytase( 0 and 0.015%) and PP(0.26% and 0.33%) level. Basal diet was negative control diet (according to Phycheck model, dietary calcium, phosphorus, energy and amino acids level was decreased from positive control diet) and positive control was designed in each PP level. 1248 one-day-old Avian broilers were assigned into six treatments with eight replicates (female/male by half) and 26 birds per pen. The results showed:1.After adding phytase into low-PP diet, as for male broilers, average body weight(ABW) and 1-42day body weight gain(BWG) was improved by 7.23%(p<0.05) and 7.47%(p<0.05), respectively, additionally, ileal apparent digestibility of phosphorus was improved by 22.3% (p<0.01); As for female broilers, feed gain ration(F/G) of 22-42day and 1-42day was decreased by 8.80%(p<0.05) and 6.18%(p<0.05). Furthermore, ileal apparent digestibility of phosphorus and tibia phosphorus content was increased by 19.9%(p<0.05) and 33.40%(p<0.05). When merged, ABW of 42day was increased by 5.95%(p<0.05). BWG of 22-42day and 1-42day was increased by 8.53% (p<0.05) 和 6.10% (p<0.05). F/G of 22-42day and 1-42day was decreased by 6.75% (p<0.05) and 4.79%(p<0.05). Mortality of any period was not affected significantly. Ileal apparent digestibility of dry matter, protein , energy and ileal digestible energy was not affected, whereas, ileal apparent digestibility of phosphorus, tibia ash and phosphorus content was improved by 21. l%(p<0.01), 10.64%(p<0.05) and 22.95%(p<0.05) respectively. Additionally, nutrient ileal apparent digestibility, tibia ash and phosphorus content did not differ significantly from positive control. But ABW of 22day and 42day was lower than positive control(p<0.05), and so was BWG of 1-21day, 22-41day and 1-42day. F/G did not differ from positive control(p>0.05) and feed intake attended to increase when compared with negative control(p>0.05) but was lower than positive control(p>0.05).2. After adding phytase into high-PP diet, as for male broilers, F/G of 1-21 day and feed intake of 1-42day decreased by 7.31%(p<0.05) and 5.14%(p<0.05), but ileal apparent digestibility of phosphorus and tibia phosphorus content was improved by 35.5%(p<0.01) and 32.66%(p<0.05). As for female broilers, ABW of 21day and BWG of 1-21day was improved by 4.97%(p<0.05) and (p<0.05), furthermore, F/G of 22-42day and 1-42day decreased by 11 31%(p<0.05) and 8.14%(p<0.05), but feed intake decreased by 8.47%(p<0.05). Ileal apparent digestibility of dry matter and phosphorus was improved by 21.9%(p<0.01) and 50.0%(p<0.01). When merged, F/G of 22-42day and 1-42day decreased by 6.73%(p<0.05) and 5.87%(p<0.05), and ileal apparent digestibility of dry matter and phosphorus was improved by 19.7%(p<0.01) and 42.4%(p<0.01). Whereas, ileal apparent digestibility of protein, energy and ileal digestible energy did not differ significantly among 3 treatments. Tibia ash...