低温状态下日粮添加甲状腺素对蛋鸡生产性能的影响

Effect of Dietary Levothyroxine Sodium on Production Performance of Laying Hens at Low Temperature

试验旨在探究冬季环境下日粮中添加左甲状腺素钠是否对坝上长尾鸡生产性能以及体温有所影响。选取29周龄195只河北坝上纯系长尾鸡,随机分为五组,分别为试验组:甲状腺低剂量组、甲状腺高剂量组(左甲状腺素钠:50μg/只·d;100μg/只·d);对照组:清水灌胃组、抗甲状腺低剂量组、抗甲状腺高剂量组(甲巯咪唑:5 mg/只·d;10 mg/只·d)。每组设3个重复,每个重复13只,预饲期7 d,试验维持14 d。结果显示:左甲状腺素钠低剂量添加(50μg/只·d)可明显提高产蛋水平,左甲状腺素钠高剂量添加(100μg/只·d)则会明显抑制产蛋水平;左甲状腺素钠低剂量组和高剂量组蛋鸡体重明显降低(P<0.05);添加左甲状腺素钠组血液T3、T4含量极显著升高(P<0.01)。结果表明,左甲状腺素钠在适当浓度添加(50μg/只·d)可以明显提高产蛋期蛋鸡的生产性能。

This experiment aimed to investigate the effect of supplementation with levothyroxine sodium on production performance and body temperature of Bashang long-tailed chickens in winter. A total of 195 Bashang long-tailed chickens from Hebei Bashang were selected at 29 weeks of age and were randomly divided into 5 groups： test groups： levothyroxine sodium group （high dose： 100μg/bird, d; low dose： 50 μg/bird, d）; control group： water irrigation group, 2-Mercapto-l-methylimidazole group （high dose： 10 mg/bird.d; low dose： 5 mg/bird.d）; each group had three replicates, each replicate had 13 chickens. The experiment was maintained for 14 days. The results showed that low dose of levothyroxine sodium （50 μg/bird, d）could significantly increase laying performance, high dose of levothyroxine sodium （100 μg/bird.d）could significantly inhibit laying performance level; The low-dose group and high-dose group had significantly lower body weight （P〈0.05）. The levels of T3 and T4 in levothyroxine sodium group were significantlyincreased （P〈0.01）. The results showed that the addition of levothyroxine sodium at the appropriate c, oncentration （50 μg/bird.d） could significantly improve the production performance of laying hens.