不同类型植物甾醇对蛋鸡脂类代谢的影响

旨在研究不同类型植物甾醇对蛋鸡脂类代谢的影响。选用72只30周龄伊莎褐蛋鸡,随机分为3组,每组8个重复,每重复3只。试验分组如下:(1)对照组,饲喂基础日粮;(2)天然植物甾醇组(NP),饲喂基础日粮+22.2 mg/kg天然植物甾醇(纯度为90%,植物甾醇净含量为20 mg/kg);(3)水溶性植物甾醇组(WP),饲喂基础日粮+50 mg/kg水溶性植物甾醇(纯度为40%,植物甾醇净含量为20 mg/kg)。试验为期8周。结果表明,添加2种植物甾醇使第4周血清三酰甘油(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)含量较对照组均有降低的趋势(P<0.1);WP组第4周脂蛋白脂酶(LPL)、肝脂酶(HL)和总酯酶(TL)活性较对照组有提高趋势,NP组血清HL活性也有提高的趋势(P<0.1),但在第8周各组均无显著差异;WP组第8周的蛋黄胆固醇含量显著低于NP组(P<0.05),而NP组与对照组差异不显著。本试验结果提示2种植物甾醇均有降低血脂和提高脂蛋白代谢酶活性的趋势,且此趋势随着时间的延长而逐渐消失,但对蛋黄胆固醇沉积无显著影响,只有WP在饲喂一段时间后有一定降低作用。

Effect of Different Phytosterols on Lipid Metabolism of Laying Hens

The experiment was conducted to study the effect of different phytosterols on lipid metabolism of laying hens.Seventy-two 30-week-old ISA Brown hens were randomly divided into 3 groups with 8 replicates per group,and fed a basal diet and the same diet supplemented with 22.2 mg natural phytosterol(NP,90% purity) or 50 mg water-soluble phytosterol(WP,40% purity) per kg of diet,respectively.The trial lasted for 8 weeks.The results indicated that phytosterol tended to reduce the content of serum triglyceride(TG),total cholesterol(TC),high density lipoprotein cholesterol(HDL-C) and low density lipoprotein cholesterol(LDL-C) at 4 week(P<0.1).Supplementation of WP tended to increase the activities of lipoprotein lipase(LPL),hepatic lipase(HL) and total lipase(TL) in serum,and the same trend was observed for serum HL activity in hens fed NP diet at 4 week(P<0.1).There was no difference in these enzyme activities at 8 week.Yolk cholesterol content was reduced by WP compared with NP at 8 week(P<0.05).No difference was observed in yolk content between NP and control group.The results suggest that two types of phytosterol tend to reduce lipid contents in serum and increase the activities of enzymes related to lipoprotein metabolism,and this trend disappear with time.Phytosterol supplementation does not significantly affect cholesterol retention in egg yolk,and only WP has a little reductive effect after feeding for some time.