本试验旨在探讨饲粮不同非纤维性碳水化合物和中性洗涤纤维比(NFC/NDF)条件下,诱导奶山羊发生亚急性瘤胃酸中毒(SARA)过程中瘤胃上皮细胞胰岛素样生长因子Ⅰ(IGF-Ⅰ)及胰岛素样生长因子Ⅰ受体(IGF-Ⅰ R)的基因表达量的变化.选用12只泌乳期关中奶山羊为试验动物,试验分4期进行,每期15 d,依次饲喂NFC/NDF分别为1.02(Ⅰ期)、1.24(Ⅱ期)、1.63(Ⅲ期)、2.58(Ⅳ期)的4种饲粮,以逐渐增加饲粮精料的方式诱导奶山羊发生SARA,并采用实时定量PCR(qRT-PCR)法对瘤胃上皮细胞中IGF-Ⅰ及IGF-Ⅰ R的基因表达量的变化进行相对定量分析.结果表明:随着饲粮NFC/NDF的升高,IGF-Ⅰ及IGF-Ⅰ R的基因表达量均出现不同程度的增加,Ⅱ期、Ⅲ期和Ⅳ期IGF-Ⅰ的基因表达量分别是Ⅰ期的1.70、2.71和9.61倍,IGF-Ⅰ R的基因表达量分别是Ⅰ期的1.88、3.09和10.19倍.饲粮NFC/NDF为2.58(即SARA期)时,与Ⅰ期相比,IGF-Ⅰ和IGF-Ⅰ R的基因表达量均出现极显著增加(P＜0.01).结果提示,以提高饲粮NFC/NDF的方法逐渐诱导SARA,IGF-Ⅰ及IGF-Ⅰ R的基因表达量显著提高,SARA发生后,它们的表达量有大幅增加.%The objective of this study was to investigate the changes of expressions of insulin-like growth factor I (IGF- I ) and insulin-like growth factor I receptor (IGF- R) genes in the ruminal epithelium of dairy goats in the process of inducing subacute rumen acidosis ( SARA) under the condition of different dietary ratios of non-fiber carbohydrate and neutral detergent fiber (NFC/NDF), This study was designed for four experimental periods with twelve lactating Guanzhong dairy goats, and 15 days in each period. Goats were fed 4 diets with different NFC/NDF (1. 02 , 1. 24, 1. 63 and 2. 58 , respectively). The induction of SARA was conducted by the gradual increase of dietary NFC/NDF, and expressions of IGF-1 and IGF- I R genes were quantitatively analyzed by quantitative real-time PCR (qRT-PCR). The results showed as follows: expressions of IGF- I and IGF- I R genes were both increased with the gradual increase of dietary NFC/NDF. The expression of IGF- I gene in periods II , E and FV was 1. 70 , 2.71 and 9.61 times of that in period I , respectively , and the expression of IGF- I R gene in periods II , 1 and IV was 1.88, 3. 09 and 10.19 times of that in period I , respectively. Compared with period I , expressions of IGF- I and IGF- I R genes significantly were increased when NFC/NDF reache 2.58(F<0.01). In conclusion, induction of SARA using the method of increasing dietary NFC/NDF can significantly increase expressions of IGF- I and IGF- I R genes, and they are increased sharply after SARA occurs. [ Chinese Journal of Animal Nutrition, 2012, 24(10) :2036-2043]
展开▼
