Effect Of Enzyme On Production Performance And Digestion In Mule Ducks Fed On Miscellaneous Meals

All trials were conducted to investigate the effect of compound enzyme on production performance,nutrient digestibility in mule ducks,in order to select the appropriate dietary supplements of miscellaneous meals.Otherwise,the compound enzyme was supplemented in the appropriate dietary supplements of miscellaneous meals to investigate the effects of compound enzyme on enzyme activitives of digestive tract and structure of alimentary canal in mule ducks.Exp.1 was conducted to investigate the effect of compound enzyme on production performance,nutrient digestibility in mule ducks fed on miscellaneous meals.All of 320 mule ducks at 3 weeks were randomly allocated to 4 groups with each group including 4 replicates and 20 birds(10 males and 10 females)per replicate.The control group was fed 8% miscellaneous meals(rapeseed meal and cottonseed meal);Three trial groups(groupⅠ, groupⅡand groupⅢ)were fed 14%,16%and 18%miscellaneous meals with 0.18 g·kg^-1 compound enzyme,respectively.Under the same conditions,the experiment was conducted to study the effect of compound enzyme on growth performance,nutrient digestibility and economy benefit of mule ducks from 3 to 8 weeks to select the appropriate dietary supplements of miscellaneous meals.The results showed that,the growth performance, nutrient digestibility and economy benefit of three trial groups were no significant difference than control group(P＞0.05).But the gain costs of three trials were reduced by 0,0.09 and 0.01 yuan,respectively.Analysing from body gain,feed/gain,nutrient digestibility and economy benefit,the appropriate dietary supplements of miscellaneous meals is 16%.Exp.2 was conducted to investigate the effect of compound enzyme on enzyme activitives of digestive tract and structure of alimentary canal in mule ducks fed on miscellaneous meals.All of 60 mule ducks at 15 days were randomly allocated to 3 groups with each group including 20 birds(10 males and 10 females)per groups.GroupⅠwas fed corn-soybean meal diet.GroupⅡwas fed 16%miscellaneous meals(confirmed from Exp.1), and groupⅢwas fed 16%miscellaneous meals with 0.18 g·kg^-1compound enzyme.The experiment was designed to observe the effect of compound enzyme on trypsin activities, amylase activities,lipase activities of pancreas and small intestine chime and structure of alimentary canal in 21 days old and 28 days old mule ducks.The results showed that, (1)Compound enzyme enhances the trypsin activities of pancrease and small intestine chyme in 21 days old and 28 days old mule ducks.(2)There are no significant difference in the anmylase activities of pancrease and enhances the anmylase activities of small intestine chime in mule ducks at 21 days old and 28 days old.(3)Compound enzyme enhances the lipase activities of pancrease at 21days and small intestine chime at 21 days and 28 days. There is no significant difference in the lipase activities of pancrease at 28 days.(4) Compound enzyme increases the villus height of duodenum and jejunum at 21days old and 28 days old,and improves the absorbency of nutrients.But the villus height of ileum was reduced.(5)Compound enzyme reduces the crypt depth of duodenum,ileum and jejunum at 21 days old and 28 days old,and the absorbency of nutrients were improved.(6)Compound enzyme improves VCR of duodenum,ileum and jejunum in mule ducks at 21days old and 28 days old.In conclusion,the ducks which were fed high level of miscellaneous meals with compound enzyme can gain similar production performance and better economy benefit to that fed low level of miscellaneous meals without compound enzyme.Following the results, the appropriate dietary supplements of miscellaneous meals was 16%.The experiment also indicated that,compound enzyme can improve the absorbency of nutrients and promote the growth of mule ducks.