Effects of Low Energy Diets Supplemented with High Dose of Complex Enzyme on Growth Performance,Nutrient Utilization and Organ Indexes of Broilers

TANG Haiou 1 GAO Xiuhua 1,2* LI Xuejun 2 WANG Xiaorui 2(1.Feed Research Institute,Chinese Academy of Agricultural Sciences,Beijing 100081,China; 2.National Engineering Research Center of Biological Feed,Beijing 100081,China)

low energy diet;complex enzyme;broiler;growth performance;nutrient utilization;organ indexes

This experiment w as conducted to investigate the effects of low energy diets supplemented w ith different doses of complex enzyme on grow th performance,nutrient utilization and organ indexes of broilers. Three hundred and tw enty one-day-old broilers w ere randomly assigned to four groups w ith eight replicates per group and ten broilers per replicate.The positive control(PC) group w as fed a conventional diet(corn-soybean meal type diet).Relative to the diet of PC group,the metabolizable energy(M E) of the negative control(NC) group diet was reduced by 210 kJ/kg,and the contents of miscellaneous meal and wheat ingredients w ere increased.The conventional additive dose of enzyme(CADE) and high additive dose of enzyme groups w ere fed the NC group diet supplemented w ith 0.02% and 0.20% complex enzyme,respectively.The trial lasted for 21 d.The results show ed as follow s: the average daily gain in the HADE group w as significantly higher than that in the other groups(P < 0.05),but there w as no significant difference among the other groups(P >0.05).The feed/gain in the PC,CADE and HADE groups was significantly lower than that in the NC group(P < 0.05 or P < 0.01),and the feed / gain in the HADE group w as significantly low er than that in the CADE and PC groups(P < 0.05),w hile no significant difference w as found betw een CADE and PC groups(P >0.05).As for dry matter apparent metabolizability,the HADE group was significantly higher than the NC group(P < 0.05),but there w as no significant difference among the other groups(P > 0.05);as for crude protein apparent metabolizability,the CADE and HADE groups w ere extremely significantly and significantly higher than the PC(P < 0.01) and NC groups(P < 0.05),respectively;as for ether extract apparent metabolizability,the NC group w as extremely significantly low er than the other groups(P < 0.01),and the CADE and PC groups w ere significantly low er than the HADE group(P < 0.05);as for apparent metabolizable energy,the HADE group w as significantly higher than the other groups(P < 0.05),but there w as no significant difference among the other groups(P > 0.05);as for energy apparent metabolizability,the CADE and HADE groups w ere extremely significantly higher than the PC and NC groups(P < 0.01),and the HADE group w as significantly higher than the CADE group(P < 0.05).Compared w ith the NC group,the indexes of stomach,pancreas and liver in CADE and HADE groups w ere significantly or extremely significantly decreased(P < 0.05 or P < 0.01),w hile the bursa of Fabricius index w as significantly or extremely significantly increased(P < 0.05 or P < 0.01).In conclusion,the supplementation of complex enzyme in the diet,in w hich the M E is reduced by 210 kJ / kg and the contents of miscellaneous meal and w heat ingredients are increased,the grow th performance,nutrient utilization and organ indexes of broilers are improved.The effect of complex enzyme is significantly increased w hen the dose of complex enzyme is enhanced from 0.02% to 0.20%.