Abstract:

This experiment was conducted to study the effects of alfalfa saponins on egg qualities of laying hens. 480 healthy Hailanhe laying hens of 23-weeks-old were randomly divided into 8 groups with five replicates and 12 layers per replicates. The trial lasted 45 days. The negative control group were fed with basal diet, the positive control groups were fed with the test diet supplied with 5% alfalfa meal, the other six groups were fed with the basal diets added with 500, 1 000, 1 500, 2 000, 2 500 and 3 000 mg of alfalfa saponins (the content of total saponins was 34%) per kilogram. The results showed that:neither alfalfa saponins nor alfalfa meal had significant and regular effects on egg weight, egg shape index, egg yolk index, eggshell relative weight, egg yolk relative weight and eggshell thickness. Alfalfa meal could significantly improve yolk color, but in the alfalfa saponins treatments had insignificance decrease on yolk color. The egg yolk color of alfalfa meal group were higher than that of control group and test groups, and had significant increase to all the test groups at 15 d and 45 d in the experiment (P<0.05); neither alfalfa saponins nor alfalfa meal had significant and regular effects on the egg yolk cholesterol concentration and egg cholesterol concentration; but the egg yolk cholesterol concentration of all the test groups and alfalfa meal group have insignificance decrease to that of control group at 15 d, 30 d and 45 d in the experiment, and the egg cholesterol concentration of all the test groups and alfalfa meal group have insignificance decrease to that of control group at 15 d and 45 d in the experiment. In summery, alfalfa saponins had no effects on general egg qualities,egg yolk cholesterol concentration and egg cholesterol concentration.

Key words: Laying hens, Alfalfa saponins, Egg quality, Yolk color, Egg yolk cholesterol

摘要：

本试验以海兰褐蛋鸡为研究对象，探索苜蓿皂苷对蛋品质及胆固醇含量的影响。将480只23周龄海兰褐蛋鸡随机分为8组，每组5个重复进行试验，对照组（基础日粮），苜蓿草粉组（5%苜蓿草粉），处理I~VI组在基础日粮中分别添加500，1 000，1 500，2 000，2 500，3 000 mg·kg^-1苜蓿皂甙（总甙含量34%），于试验第1，15，30，45天时测定蛋重、蛋形指数、蛋壳厚度、蛋壳相对重、蛋黄指数、蛋黄颜色和蛋黄胆固醇含量。结果表明：苜蓿皂甙和苜蓿草粉对常规蛋品指标无显著影响；苜蓿草粉对蛋黄颜色有明显提高作用（P<0.05），皂甙处理组蛋黄颜色较对照组有所降低。苜蓿草粉处理下蛋黄颜色均高于对照组和处理组，且在15天和45天时显著高于所有处理组；苜蓿皂甙对蛋黄胆固醇浓度和鸡蛋胆固醇含量无显著影响；但是，在15，30和45天时，处理组与苜蓿草粉组的蛋黄胆固醇浓度较对照组有所降低但差异不显著，在15天和45天时，处理组与苜蓿草粉组的鸡蛋胆固醇浓度较对照组有所降低但不显著。因此苜蓿皂甙对常规蛋品指标没有影响，对降低鸡蛋中胆固醇浓度与胆固醇含量没有显著作用。

关键词: 蛋鸡, 苜蓿皂甙, 鸡蛋品质, 蛋黄颜色, 蛋黄胆固醇