Effects Of Lipase On Growth Performance And Nutrient Availability In Yellow-feathered Broilers

This experiment was conduct to investigate the effects of dietary lipase on growth performance and nutrient digestibility of yellow-feathered broilers.The experiment was divided into two periods:starter(1 to 21 d)and grower(22 to 42 d)periods.600 1-day-old healthy yellow-feathered broiler chickens were randomly allocated to 5 treatments with 6 replicates in each treatment and 20 chickens per replicate.Treatments included a high fat diet control group[HFD group,metabolizable energy(M E): 1 to 21 d 12.13 MJ/kg,22 to 42 d 12.76 MJ/kg],medium fat diet control group[MFD group(ME of HFD diet minus 210 kJ/kg)],low fat diet control group [LFD group(ME of HFD diet minus 420 kJ/kg)]and lipase addition in the medium、low diet control group(MFD+lipase group and LFD+lipase group).The results showed as follows:1)Compared with HFD,the average daily gain(ADG)of MFD and LFD 21-42 d was significantly decreased(P<0.05);the feed-to-weight ratio(F/G)of MFD 21-42 d and 1-42 d were significantly increased),LFD full-term F/G was significantly increased(P<0.05).The ADG of MFD + lipase and LFD + lipase 21-42 d were significantly higher than that of MFD and LFD(P<0.05);MFD + lipase 21-42 d and 1-42 d F/G were significantly decreased(P<0.05),LFD+lipase Period F/G was significantly lower(P<0.05).Average daily feed intake(ADFI)was not significantly different among all groups(P>0.05).Two-factor analysis showed that lipase could significantly reduce the 21-42 d and 1-42 d F/G of yellow-feathered broilers(P<0.05).2)Compared with HFD,the apparent metabolic rate of MFD,the apparent utilization of dry matter and the apparent utilization rate of crude fat were not significantly different(P>0.05).The apparent metabolism of LFD was significantly decreased(P<0.05).Compared with the MFD and LFD,the apparent utilization rate of crude fat of MFD+lipase and LFD+lipase was significantly increased(P<0.05).Two-factor analysis showed that lipase significantly increased the apparent utilization of crude fat(P<0.05).The results suggest that decreasing.dietary energy levels decreased by 210 kJ/kg and 420 kJ/kg,respectively,and decreased ADG and F/G in different degrees in different stages of the diet;Lipase supplementation in low-energy diets increased apparent utilization of crude fat,improve fat absorption,improve the performance of broiler growth.