不同苜蓿草粉水平对产蛋鸡蛋黄胆固醇含量影响的研究

Study on effect of Medicago sativa meal on egg yolk cholesterol concentration of layers

选择健康35周龄新罗曼商品代蛋鸡768只,采用2×4因子试验设计,随机分为8 个处理组,每组3 个重复,每个重复32只,分别在饲粮中添加0,3%,5%,7%的紫花苜蓿草粉和1.6%和2.4%的油脂,试验期60 d,观测苜蓿草粉和油脂对鸡蛋蛋黄重、蛋黄相对重、每克蛋黄胆固醇含量以及每枚鸡蛋中胆固醇含量的影响。结果表明:1)添加苜蓿草粉和油脂后,对蛋黄相对重无显著影响(P>0.05);蛋黄重有显著增加,其中低油脂组中7%草粉添加组蛋黄重极显著高于不添加组(P<0.01),各添加组之间差异不显著;高油脂组中各添加组之间无显著差异;每g蛋黄胆固醇含量有较大降低,添加草粉后,各试验组较不添加组极显著降低每g蛋黄中胆固醇含量(P<0.01);每枚蛋中胆固醇含量有显著降低,其中高油脂组中5%和7%草粉添加组蛋黄重极显著高于不添加组(P<0.01),各添加组之间差异不显著。二者的交互作用中,苜蓿水平对鸡蛋中胆固醇的影响高于油脂水平。2)随着苜蓿草粉添加水平的增加,每g蛋黄中胆固醇含量和鸡蛋中胆固醇含量逐渐降低,每g蛋黄中胆固醇含量在前30 d下降较快,随后逐渐降低,试验至45 d时趋于平稳。

An experiment was conducted using 768 New Lohmann Layers aged 35 weeks to study the effect of M. sativa meal on yolk weight, yolk relative weight, egg yolk cholesterol concentration and egg cholesterol concentration. Layers were randomly divided into eight treatments according to a 2×4 factorial arrangement, each treatment represented by three replicates of 32 birds each Layers were fed corn-soybean based diet with 0, 3%, 5%, 7% M. sativa meal and 1.6%, 2.4% fat during the phrase of 60 days. The results showed that: 1)Layers added M. sativa meal and fat had no significant difference of yolk relative weight(P>(0.05))than that of no meal treatment. Yolk weight was increased according to the increasing of M. sativa meal additive, addition of M. sativa meal cholesterol concentration, Eggs given the diets at 7% diet extremely significantly increased(P<(0.01))in the low fat treatment, the others had no difference. Addition of M. sativa meal significantly decreased(P<(0.01))egg yolk added with M. sativa meal had a lower(P<(0.01))egg cholesterol concentration than those given no M. sativa meal diets. During the interaction, M. sativa source had more effect on egg yolk cholesterol concentration and egg cholesterol concentration that fat source. 2)Egg yolk cholesterol concentration and egg cholesterol concentration decreased with M. sativa meal increasing, egg yolk cholesterol concentration decreased sharply in the former 30d, then reached a consistence level at the 45th day of experiment.