锰对5～16周龄五龙鹅生长性能、屠宰性能、营养物质利用率及酶活性的影响

Effects of Manganese on Growth Performance,Slaughter Performance, Nutrient Availability and Enzyme Activity of Wulong Geese Aged from 5 to 16 Weeks

本试验旨在研究锰对5～16周龄五龙鹅生长性能、屠宰性能、营养物质利用率及酶活性的影响，以确定鹅饲粮中锰的适宜添加水平。试验选用5周龄体重相近的五龙鹅360只，随机分为6个组，每组6个重复，每个重复lO只（公母各占1／2）。各组分别在基础饲粮（锰含量为20mg／kg）中添加0（Ⅰ组）、30（Ⅱ组）、60（Ⅲ组）、90（Ⅳ组）、120（Ⅴ组）、150mg／kg（Ⅵ组）的锰。试验期为12周。结果表明：1）采用不相关比较法进行分析，饲粮锰添加水平为104．90mg／kg时平均日增重最大，饲粮锰添加水平为117．63mg／kg时料重比最低。2）Ⅳ、Ⅴ组屠宰率、半净膛率、全净膛率和腿肌率分别显著和极显著高于Ⅰ组（P〈0．05和P〈0．01），V组腹脂率显著低于Ⅰ组（P〈0．05）。3）Ⅳ、Ⅴ组粗蛋白质、粗脂肪、钙、磷、粗纤维利用率显著或极显著高于Ⅰ组（P〈0．05或P〈0．01），Ⅴ组中性洗涤纤维和酸性洗涤纤维利用率及表观代谢能和真代谢能显著高于Ⅰ组（P〈0．05）。4）Ⅴ组合锰超氧化物歧化酶（MnSOD）活性极显著高于Ⅰ组（P〈0．01），Ⅳ、Ⅴ组苹果酸脱氢酶（MDH）和脂蛋白脂酶（LPL）活性显著或极显著低于Ⅰ组（P〈0．05或P〈0．01）。15）MnsOD、MDH和LPL活性与生长性能有极显著相关性（P〈0．01）；MDH和LPL活性与营养物质利用率有极显著相关性（P〈0．01）。由此可知，适宜饲粮锰添加水平能够提高5～16周龄五龙鹅的生长性能、屠宰性能和营养物质利用率，降低腹脂率，建议鹅饲粮中锰添加水平为104．90～117．63mg／kg。MDH和LPL活性与生长性能和营养物质利用率极显著相关。

This experiment was conducted to study the effects of manganese on growth performance, slaughter performance, nutrient availability and enzyme activity of Wulong geese aged from 5 to 16 weeks, and to find the appropriate supplemental level of manganese. A total of 360 Wulong geese with similar average body weight were randomly divided into 6 groups with 6 replicates per group and 10 geese （ half male and half fe- male） per replicate. Geese in the groups were fed the basal diet （ manganese content 20 mg/kg） supplemented with 0 （group Ⅰ ）, 30 （group Ⅱ ）, 60 （group Ⅲ ）, 90 （group Ⅳ）, 120 （group Ⅴ ） and 150 mg/kg （ group Ⅵ ） manganese, respectively. The experiment lasted for 12 weeks. The results showed as follows ： 1 ） using unrelated comparative analysis method, when the dietary manganese level was 104.90 mg/kg, the aver- age daily gain reached the highest; when the dietary manganese level was 117.63 mg/kg, the feed to gain reached the lowest. 2 ） The dressed percentage, percentage of half-eviscerated yield, percentage of eviscerated yield and percentage of leg muscle in groups Ⅳ and Ⅴ were significantly higher than those in groupⅠ （P 〈 0.05 and P 〈 0.01, respectively）, the percentage of abdominal fat in group Ⅴ was significantly lower than that in groupⅠ （ P 〈 0.05）. 3） The availability of crude protein, ether extract, calcium, phosphorus, crude fiber in groups Ⅳ and Ⅴ was significantly higher than that in group Ⅰ （ P 〈 0.05 or P 〈 0.01 ） , the availabili- ty of neutral detergent fiber and acid detergent fiber, apparent metabolizable energy and true metabolizable en- ergy in group Ⅴ were significantly higher than those in group Ⅰ （ P 〈 0.05）. 4） The manganese superoxide dismutase （MnSOD） activity in group Ⅴ was significantly higher than that in groupⅠ （P 〈0.01 ）, and the malic dehydrogenase （MDH） and lipoproteinesterase （LPL） activities in groups Ⅳ and Ⅴ were significantly lower than those in group Ⅰ（P 〈0.05 or P 〈 0.01 ）. 5） MnSOD, MDH and LPL activities had significant correlation with the growth performance （ P 〈 0.01 ）, MDH and LPL activities had significant correlation with the nutrient availability （ P 〈 0.01 ）. In conclusion, dietary manganese at appropriate supplemental level can promote growth performance, slaughter performance and nutrient availability of Wulong geese aged from 5 to 16 weeks, but decrease the percentage of abdominal fat, and the optimal supplemental level of manganese is 104.90 to 117.63 mg/kg. MDH and LPL activities have significant correlation with the growth performance and nutrient availability.