| This experiment was conducted with Cherry Valley Female Meat duck to study the effect of MOS on the production performances blood biochemical indicator and the main microorganism of caecum. The purpose was to determine the optimal level of MOS on the meat duck and to explain the mechanism of its effects preliminarily.300 Cherry Valley female meat duck of 7-day old were assigned randomly into 5 groups each with 3 replicates for a 5-week trial. The basical diet was corn-soybean, containing no antibiotics nor prebiotics. The groups were fed with basical diets adding 0%(control group), 0.05%, 0.1%, 0.2% and 0.4% MOS. the production performance, blood biochemical indicator and the main microorganism of caecum were determined. The main results were showed as follows: (l)Dietary MOS remarkably promoted production performance: at the age of 43 day, the average body weight of group IK HI, IV, V increased by 2.70% (P>0.05), 5.96%(P<0.01) , 5.15(P<0.05) and 1.86%(P>0.05) with the changes of MOS compared with control group. The third group had the highest average body weight. It also increased the average daily gain of II, III, IV, V groups, increased 2.69%(P>0.05), 6.65%(P<0.01), 5.34%(P<0.05) and 1.92%{P>0.05) respectively. But it had no obviously effect on the average daily feed intake (P>0.05). The feed-meat ratio of the II , III, IV, V groups decreased 2.05% (P>0.05), 6.15% (PO.05), 4.10% (P>0.05) and 3.69% (P>0.05) compared with control group, the third group was the lowest. (2)The slaughter rate, semi-net rate and the whole-net rate of the HI, IV, V groups were in the upward trend, but no significant difference. Among all the groups, the third group was the best, higher than control group by 3.25%(P>0.05), 3.30%(P>0.05), 3.06%(P>0.05), respectively. It did not obviously affect the rate of abdominal lipid except for the third group(decreased11.13% compared with the control group(P<0.05)). The dietary MOS also did not affect the marbling evaluation - pH value and shearing force of the musculus pectoralis(P>0.05), but the water-holding capacity of musculus pectoralics of IK EL IV , V were higher(2.17%(P>0.05) , 3.24%(P>0.05) , 10.52%(P<0.05) and 1.32%(P>0.05)) than control group and the fourth group was the best. (3)The diets added with MOS could increase the utilization rate of nutrient substance. In the early and later period of experiment, the utilization rate of dry matter crude asru organic matter and crude protein of IK IIL IV > V groups were all higher than those of control group, the difference of III> IV group were significant (PO.05) or extremely significant (PO.01). (4)At the end of the trial, the blood total cholesterol decreased 4.15%(P>0.05) , 6.65% ( PO.05 ) , 6.04%(P>0.05) and ,7.19% ( P<0.05 ) , respentively. The difference among all the experimental group was not significant. The dietary MOS slightly increased the blood sugar (P>0.05) and decreased the BUN(Blood Uninary Nitrogen) (P>0.05). It could significantly increase the serum albumin (PO.05), but the difference among all the experimental group were not significant (P>0.05). It could also increase the serum IgG, only group III reached significant level. Furthermore, the concentraton of serum T3, but for the second group, of the rest experimental groups was higher than control group (PO.05), and the third group was extremely higher than all the other groups (PO.01). The difference of the serum T4 were not significant among all the groups. (5)The dietary MOS did not affect the pH value in deodenum -, jejunum and ileum, only III, IV group slightly decreased (P>0.05), the caecum pH value of IIL IV > V groups were significantly lower than the control group (PO.05). The lactic acid of bacillus of caecum content in third and forth group higher than control group and the rest (PO.01). but the difference between them was not obviously (P>0.05). The E.coli-index of HI, IV > V groups were lower than control group (PO.01), and the third group also significantly lower than the fifth group. Among all the rest groups, there were no significant diff... |
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