| The trial used 135 average weight (7.2±0.2) kg of Duroc×Landrace×Yorkshire crossbred weaned piglets,using 3×3 crossing design trial, studied the dietary levels of neutral protease 3 (0,40mg/kg and 80mg/kg) and three levels of acid protease (0,40mg/kg and 80mg/kg) on growth performance, nitrogen and amino acid apparent digestibility, blood biochemistry indexes, to find the best of the neutral and acid protease with the program. A total of nine experimental groups of three replicates of five pigs. A trial period of 28 d, divided into early (1～14d) and later (15～28d) period The results showed that:1.Add the appropriate of neutral and acid protease in feed,the average daily gain of weaned piglets and feed gain ratio were significantly effect (P<0.05). Which add 80mg/kg neutral protease and acid protease effect of the best, but only in the diet containing 80mg/kg acidic protein, the highest feed conversion ratio (P<0.05). Neutral and acid protease there is a significant interaction effect (P<0.05)2.Diet of seed suitable neutral and acidic protease can increase the apparent nitrogen digestibility of weanled pigs to reduce fecal nitrogen, urinary nitrogen and total nitrogen excretion and improve nitrogen utilization. Which add 80mg/kg neutral protease and 40mg/kg acid protease can significantly increase the apparent nitrogen digestibility of weaned piglets (P<0.05), and add 80mg/kg 80mg/kg neutral protease and acid protease least effective, but the compared with the control group was not significant (P>0.05); fecal nitrogen, urinary nitrogen and total nitrogen excretion tended to decrease, but the difference was not significant (P>0.05). Neutral and acid protease there is a significant interaction effect (P<0.05)3.Add the appropriate types of dietary neutral and acid protease significantly increased lysine, methionine, valine, threonine, histidine, serine, alanine apparent digestibility (P<0.05). Which add 80mg/kg neutral protease and40mg/kg acid protease effect of the best, and add 80mg/kg neutral protease and 80mg/kg acid protease worst. Neutral and acid protease there is a significant interaction effect. (P<0.05)4.Add the appropriate types of dietary neutral and acidic protease can enhance the different levels of serum glucose, total protein, decreased urea nitrogen content, which add 80mg/kg neutral protease and 40mg/kgacid protease can significantly improve the post-blood glucose levels (P<0.05), urea nitrogen decreased significantly (P<0.05); neutral and acid pre-and post-aspartate protease, alanine aminotransferase levels not significantly different (P>0.05). Neutral and acid protease there is a significant interaction effect (P<0.05). Neutral and acid protease there is a significant interaction effect. (P<0.05)In conclusion:Adding the appropriate of neutral and acid protease in feed can enhance the growth performance of weanled piglets, apparent digestibility of nitrogen and amino acids. Combination of indicators, neutral and acid protease optimal dose combination: addition of 80mg/kg neutral protease, acidic protease addition of 40mg/kg. |
