Effects Of Different Levels Of Metabolizable Energy And Crude Protein And Calcium On The Fatty Liver Performance Of The Mule Ducks

This experiment was conducted to study the effects of different levels of metabolizable energy (ME) and crude protein (CP) and calcium (Ca) on the fatty liver performance of the mule ducks during the overfeeding. The levels of ME were 11.56MJ/kg, 12.98MJ/kg and 13.40MJ/kg respectively; the levels of the CP were 9%, 10.5% and 12% respectively; the levels of the calcium were 0.85%, 0.95% and 1.05% respectively. 12 weeks old 180 mule ducks, were randomly assigned into 9 groups each with 4 replicates of 5 birds according to L₉ (3⁴) orthogonal design, and fed the different nine kinds of diets which were mainly composed of corn. The purpose of trails was to determinate the optimum nutrition density of ME, CP and Ca of the mule duck during the overfeeding. The results were as follows.The fatty liver weights showed a significant difference among the nine groups after overfeeding (P<0.01). Among the nine experimental diets for overfeeding, the 5^th dietary treatments had obtained the best fatty liver performance that the fatty liver weight and the ratio of feed intake and fatty liver weight at the end had reached 436.80g and 22.15:1 respectively, which the nutrition levels were 12.98MJ/kgME. 10.5%CP, 0.85%Ca respectively. The significance of these factors was the following order: ME > Ca> CP. The fatty liver performance showed a significant difference among the different levels of ME and different levels of Ca (P<0.05). No significant difference was observed among different levels of CP (P>0.05).The fatty liver composition including total lipids, protein and water and calcium contents showed a significant difference among the nine groups after overfeeding (P<0.01). The significance of these factors was the following order: ME > Ca> CP. The fatty liver composition showed a significant difference among the different levels of ME and different levels of Ca(P<0.01). No significant difference was observed among different levels of CP (P>0.05).The abdominal fat percentage showed a significant difference among the nine groups after overfeeding (P<0.01). The significance of these factors was the following order: ME > Ca> CP. The abdominal fat percentage showed a significant difference among the different levels of ME (P<0.01). No significant difference was observed among different levels of CP and different levels of Ca (P>0.05).The results suggested that the optimum dietary nutrition density of mule duck during overfeeding was 12.98MJ/kg ME, 10.5%CP and 0.85%Ca respectively, which had obtained the best fatty liver performance. The significance of these factors was following order: ME > Ca> CP.