植物甾醇对肉鸭胆固醇代谢和抗氧化性能的影响

2000只15日龄的商品代樱桃谷肉鸭随机分成5组,每组4个重复,每个重复100只肉鸭,分别饲喂添加0(对照组)、10、20、40、80mg/kg植物甾醇日粮。42日龄试验结束时,每组随机抽取公、母鸭各5只屠宰,测定各项指标。结果表明,植物甾醇对生产性能无显著影响(P>0.05)。植物甾醇降低了肉鸭血清中总胆固醇(TC)和低密度脂蛋白胆固醇(LDL-C)的含量,当添加量为40mg/kg时差异显著(P<0.05);日粮中添加10mg/kg、20mg/kg和40mg/kg植物甾醇后,肉鸭肝脏胆固醇合成速度明显加快;添加80mg/kg植物甾醇的试验组肉鸭,血浆中总超氧化物歧化酶(T-SOD)活性显著(P<0.05)升高,添加10或40mg/kg植物甾醇的组,肝脏中T-SOD活性显著(P<0.05)升高。结果提示植物甾醇可能通过抑制低密度脂蛋白的生成来降低血脂,同时影响肝脏内源性胆固醇的合成,并且可能通过提高机体抗氧化酶活性达到抗氧化效果。

Effects of phytosterols on cholesterol metabolism and antioxidant activity in the meat-strain duck

Two thousand of commercial Cherry Valley meat-strain ducks were randomly allocated into 5 groups with 4 replicates at 15-day-old. Ducks were fed basal diet supplemented with 0 (control group), 10, 20, 40 and 80 mg/kg phytosterols, respectively. At 42 days old, 5 drakes and ducks from each treatment were slaughtered, and their lipoprotein cholesterol concentrations and antioxidant abilities were determined. The results showed that there were no significant effects on performance (P>0.05), but decreased in total cholesterol and low density lipoprotein cholesterol contents in sera of meat-strain duck with treatment of phytosterols, and decreased significantly in the group of 40mg/kg phytosterols (P<0.05) compared to control group. Hepatic cholesterol synthesis was significantly (P<0.05) increased in 10, 20 and 40 mg/kg groups, respectively. In 80 mg/kg group, the total plasma superoxide dismutase activities increased significantly (P<0.05), while, in 10 and 40 mg/kg groups, the liver dismutase increased significantly (P<0.05). These results imply that phytosterols may inhibit the formation of low density lipoprotein into lower serum cholesterol contents, and therefore affect the hepatic cholesterol synthesis. Phytosterols may also increase the activities of antioxidation enzymes, but the effect and mechanism of antioxidation remain to be elucidated.