饲粮中硒添加水平对产蛋高峰期临武鸭产蛋性能、蛋品质、血清抗氧化指标和蛋硒含量动态变化的影响

本试验旨在研究饲粮中硒添加水平对产蛋高峰期临武鸭产蛋性能、蛋品质、血清抗氧化指标和蛋硒含量动态变化的影响。试验选用29周龄体况良好、产蛋率接近的正处于产蛋高峰期的临武鸭200只,随机分为5组,每组5个重复,每个重复8只。对照组饲喂基础饲粮(不额外补充硒源,实测硒含量为0.15 mg/kg)45 d,Ⅰ组、Ⅱ组、Ⅲ组、Ⅳ组分别在基础饲粮中以酵母硒形式添加0.10、0.20、0.40、0.80 mg/kg的硒,饲喂35 d添加硒饲粮后改喂基础饲粮10 d。结果显示:1)饲粮中硒添加水平对蛋鸭产蛋性能和蛋品质各指标均无显著影响(P0.05)。2)与对照组和Ⅰ组相比,饲粮中添加0.40和0.80 mg/kg的硒可以显著提高蛋鸭血清中硒和谷胱甘肽(GSH)含量以及超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性(P0.05),显著降低血清中丙二醛(MDA)含量(P0.05)。3)随试验天数的增加,对照组和Ⅰ组蛋硒含量无显著变化(P0.05),而Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量均呈现先升高后降低的趋势,且均在试验第9天达到峰值。试验第7、9、13、17、21、28和35天,Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量显著高于对照组和Ⅰ组(P0.05);停喂添加硒饲粮的第1~4天,Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量仍显著高于对照组(P0.05);停喂添加硒饲粮的第5~8天,Ⅲ组和Ⅳ组蛋硒含量显著高于对照组(P0.05);停喂添加硒饲粮的第9天,各试验组蛋硒含量均衰减至与对照组相同水平(P0.05)。由此可见,饲粮中添加不同水平的酵母硒形式的硒对产蛋高峰期临武鸭的产蛋性能和蛋品质均无不良影响。饲粮中添加0.40和0.80 mg/kg酵母硒形式的硒可以提高产蛋高峰期临武鸭的蛋硒含量、血清硒含量和抗氧化能力,延长蛋硒的存留时效。综合考虑各因素,产蛋高峰期临武鸭饲粮中硒(以酵母硒形式添加)的适宜添加水平为0.40 mg/kg。

Effects of Selenium Supplemental Level on Laying Performance,Egg Quality,Serum Antioxidant Indices and Dynamic Change of Egg Selenium Content of Linwu Ducks during Peak Laying Period

This experiment was conducted to study the effects of selenium supplemental level on laying per-formance, egg quality, serum antioxidant indices and dynamic change of egg selenium content of Linwu ducks during peak laying period.Two hundred 29-week-old healthy Linwu ducks with a similar laying rate and in peak laying period were randomly assigned to 5 groups with 5 replicates in each group and 8 ducks per repli-cate.The ducks in control group were fed a basal diet without adding selenium source and the measured value of selenium content was 0.15 mg/kg, while the ducks in groupsⅠ,Ⅱ,Ⅲ and Ⅳ were fed the basal diet sup-plemented with 0.10, 0.20, 0.40 and 0.80 mg/kg selenium in forms of selenium yeast, respectively.The ex-perimental diets were fed with 35 d for each group, then stop to supplement selenium and the basal diet were fed within 10 days.The results showed as follows: 1) dietary selenium supplemental level had no significant effects on the indices of laying performance and egg quality of laying duck ( P>0.05) .2) Compared with the control group and groupⅠ, supplementation of 0.40 and 0.80 mg/kg selenium could significantly increase the serum selenium and glutathione ( GSH) contents, and glutathione peroxidase ( GSH-Px) and superoxide dis-mutase (SOD) activities (P<0.05), while significantly decrease the serum malonaldehyde (MDA) content ( P<0.05) .3) As the experimental days increasing, the egg selenium content in the control group and groupⅠ showed no significant change ( P>0.05) , the egg selenium content in the groupsⅡ,Ⅲand Ⅳshowed in-crease firstly and then decrease trend, and those groups reached peak in the test day 9.The egg selenium con-tent in the groups Ⅱ,Ⅲ an Ⅳ was significantly higher than that in the control group and group Ⅰat the test day 7, 9, 13, 17, 21, 28 and 35.Stop to feed selenium supplementation diets at day 1 to 4, the egg selenium content in groupsⅡ,Ⅲ and Ⅳwere still significantly higher than that in the control group ( P<0.05) .Stop to feed selenium supplementation diets at day 5 to 8, the egg selenium content in groups Ⅲ and Ⅳ was signifi-cantly higher than that in control group ( P<0.05) .Stop to feed selenium supplementation diets at day 9, the egg selenium content of all groups was recovery to the same level with control group ( P>0.05 ) .In conclu-sion, the laying performance and egg quality of Linwu duck during peak laying period are not affected by dif-ferent selenium supplemental level; antioxidant capacity, serum selenium content and egg selenium content of Linwu duck during peak laying period can be improved by supplementation of 0.40 and 0.80 mg/kg selenium in the form of yeast selenium.Supplementation of 0.40 and 0.80 mg/kg selenium can prolong the retention of egg.Comprehensive consideration of all the factors, the optimum selenium supplemental level of Linwu ducks in peak laying period is 0.40 mg/kg.