γ-氨基丁酸对生长肥育猪生长性能、血清生化指标及HPA、HPT轴激素分泌的影响

Effects of y-aminobutyric Acid on Growth Performance, Serum Biochemical Indices and Hormones of HPA and HPT Axis in Growing-finishing Swine

本试验研究不同水平的γ-氨基丁酸(GABA)对生长肥育猪生长性能、血清生化指标及HPA轴(皮质醇、皮质酮和促肾上腺皮质激素)与HPT轴(游离三碘甲腺原氨酸、游离甲状腺素、三碘甲腺原氨酸和甲状腺素)激素分泌的影响。选取96头体重约(43.0±3.2)kg的杜长大三元杂交猪,随机分为4组,每组3个重复,每重复8头(公母各1/2),分别饲喂在基础日粮中添加0(对照组)、10(组Ⅰ)、20(组Ⅱ)和40 mg/kg GABA(组Ⅲ)的试验日粮,试验期48 d。试验结束时测定猪生长性能,并从对照组及生长效果最佳组的每重复选2头,测定血液指标。结果表明:与对照组相比,3个水平的GABA对生长肥育猪的生产性能都有一定的影响,其中以10 mg/kg组效果最为显著,日增重提高13.08%(P<0.01),料重比降低7.81%(P<0.01)。10 mg/kg GABA使三碘甲腺原氨酸和游离三碘甲腺原氨酸水平显著升高(P<0.05);谷胱甘肽过氧化物酶活性极显著升高(P<0.01);乳酸脱氢酶活性及皮质醇、皮质酮和促肾上腺皮质激素水平显著下降(P<0.05)。结果提示,日粮添加GABA可提高生长肥育猪生产性能;10 mg/kg GABA使生长肥育猪的抗氧化性能及甲状腺机能增强。

This study was conducted to study the effects of γ-aminobutyric acid （GABA） on growth performance, serum biochemical indices and hormones of HPA （cortisol, corticosterone and adrenocorticotropic hormone）, HPT （free triiodothyronine, free thyroxine, triiodothyronine and thyroxine） axis in growing-finishing swine. Ninety-six （Duroc × Landrace × Yorkshine） growing-finishing pigs with an average initial body weight of （43.0± 3.2） kg were randomly allocated to four treatments with three replicates in each group and eight pigs in each replicate （1/2 male and female）. The treatments included control group without GABA, 10 mg/kg GABA group （group Ⅰ）, 20 mg/kg GABA group （group Ⅱ） and 40 mg/kg GABA group （group Ⅲ ）. The experiment lasted for 48 days. At the end of the experiment, the growth performance were determined, and two pigs in every replicate in control group and optimum growth performance group were randomly selected to determine serum biochemical parameters and hormones of HPA and HPT axis. The results showed that different levels of GABA affected growth performance of growing-finishing pigs, and 10 mg/kg was the best dosage which significantly increased the average daily gain and feed/gain ratio by 13.08% and 7.81%, respectively （P〈0.01）. Ten mg/kg GABA increased the serum concentration of triiodothyronine and free triiodothyronine （P〈0.05）; glutathione peroxidase （GSH-Px） activity was significantly increased （P〈0.01） ; but lactate dehydrogenase （LDH） activity and cortisol, corticosterone and adrenocorticotropic hormone （ACTH） concentrations were decreased（P〈0.05）. It was concluded that GABA could improve growth performance of growing-finishing pigs by increasing average daily gain and decreasing feed/gain ratio; 10 mg/kg GABA also could enhance antioxidation performance and thyroid function.