Study On The Quantitive Relationship Between Xylanase Supplementation And Protein Feed Stuffs

This trial was studied to investigate the effects of xylanase on the protein feed stuffs from different sources.This study contained two trials:the vitro trial and the metabolic trial.1.The vitro trial was conducted to measure the content of total xylan,water soluble xylan in different source of soybean meal(SBM),rapeseed meal(RSM) and cottonseed meal(CSM) and to evaluate the effects of xylanase on different protein feed stuffs in order to establish the quantities relationship of the xylanase levels and feeds.Three single-factor experiment designs were employed.Every feed ingredient was incubated with 6 different xylase level with 4 replicates,respectively.The results showed that:①the total xylan and water soluble xylan levels were influenced by the kind of feeds.The total xylan of SBM, RSM,and CSM were 5.62%,6.56%,and 8.20%,respectively;The water soluble xylan of SBM,RSM,and CSM were 0.35%,0.97%,and 0.84%,respectively.②The content of xylan was not influenced significantly by feeds source.Compared to SBM and CSM,the water soluble xylan level was significantly increased when contacting with some water.③There were significant disaggregation effects of xylanase on total xylan of three feeds with the less disaggregation effects on water soluble xylan.The greatest effects of xylanase on total xylan and water soluble xylan were for RSM.The appropriate dietary xylanase levels for SBM,RSM,and CSM were 1000u/kg,1000u/kg,and 1500u/kg respectively based on the effect on total xylan and cost of enzyme.2.The metabolic trial was conducted to test the effects of xylanase on the nutrients digestibility and AME of three protein feeds(SBM,RSM and CSM),in order to establish quantitive relationship between xylanase supplementation and SBM or RSM or CSM. Three single-factor experiment designs were employed.Every basal diet was treated with 5 different xylanase level,eight replicate cages of 1 broiler were assigned to each treatment. The results showed as follows:①supplementation with xylanase to SBM increase DM digestibility 8.43%(P＜0.05),CP digestibility 10.13%(P＜0.05),EE digestibility 19.25% (P＜0.05) and AME5.46%(P＜0.05) respectively.②supplementation with xylanase to RSM increase DM digestibility 7.49%(P＜0.05),EE digestibility 40.4%(P＜0.05) and AME6.88%(P＜0.05),there was no significant difference among all groups of the CP digestibility.③supplementation with xylanase to CSM increase DM digestibility 16.04% (P＜0.05),CP digestibility 17.5%(P＜0.05) and AME10.25%(P＜0.05),there was no significant difference among all groups of the EE digestibility.The results suggested that the appropriate xylanase supplementation levels to SBM,RSM and CSM was 1500,1500 and 1500IU/kg respectively.In conclusion:The appropriate dietary xylanase levels for soybean meal,rapeseed meal,cottonseed meal were 1500,1500,1500U/kg,respectively.