菜籽粕对肉用仔鸡血清中甲状腺激素浓度和生产性能的影响

用放射免疫分析法研究了菜籽粕对肉用仔鸡血清中甲状腺激素(T_3和T_4)浓度的影响,考察了生产性能,比较研究了仔鸡性别对菜籽粕的不同反应。结果表明:1.12％菜籽粕使仔母鸡血清三碘甲腺原氨酸浓度均值显著降低(P<0.05),尤其在饲喂菜籽粕5周以内影响更大,而对仔公鸡没有显著影响;2.12％籽菜粕对仔鸡血清甲状腺素浓度无显著影响,但前期血清甲状腺素浓度略有增加,后期略为下降;3.12％菜籽粕使仔鸡前期增重减少,料肉比增加,但对后期生产性能没有显著不良影响;4.12％菜籽粕导致仔鸡甲状腺显著增大(P<0.05),而对肝重、肾重和脾重则无显著影响:5.12％菜籽粕组8周龄仔鸡血浆中未检出恶唑烷硫酮和异硫氰酸酯等毒素。

EFFECTS OF RAPESEED MEAL ON CONCENTRATION OF THYROID HORMONES IN SERUM AND PERFORMANCE OF GROWING BROILERS

The effects of rapeseed meal (B.napus ) on scrum concentration of thyroxine ( T4) , triiodothyronine (T3) and performance of Redbro chicks were investigated using radioimmunoassay.Part of the soybean meal in the diets Avas replaced by 0%, 4% or 12% RSM during the period of 2-9 weeks of age.The results showed that:l)the serum T3 concentrations in females fed with 12% RSM were significantly depressed(P<0.05), especially before 5 weeks of age; but it was not the case in males; 2)no significant difference was observed in serum T4 levels between 12% RSM and 0% RSM groups in both males and females.However, the T4 levels tended to increase in the first period and slightly decrease in the last period; 3)the thyriod glands of 8-week-old chicks fed with 12% RSM were significantly englarged ( P<0.05) , though the weights of the liver, kidney and spleen were not significantly affected; 4)the oxazolidinethion and isothiocyanates contents in the plasma of chicks fed with 12% RSM were not detectable;5)gain in weight and feed efficiency ( Gain/Feed ) were significantly decreased(P<0.05)in 12% RSM-groups in the first period, but not changed in the last period.It was concluded that female broiler was more sensitive than male broiler and up to 12% RSM could be included in the diet of 5 to 8-week-old Redbro chicks.