中文摘要：

本试验旨在探讨断奶时间对不同日龄湖羊羔羊瘤胃形态及表皮生长相关基因表达的影响。采用两因子试验设计,设断奶时间和羔羊日龄2个因子。选择初生重[（3.51±0.57）kg]接近的54只湖羊羔羊,28日龄时随机屠宰6只后按照同质性原则将剩余48只湖羊分为28日龄断奶组[（8.21±0.97）kg]和56日龄断奶组[（8.06±0.53）kg],分别在42、56、70和84日龄从2组中各随机挑选6只羔羊进行屠宰。采集瘤胃腹囊组织样品测定瘤胃乳头长度、宽度和肌层厚度,提取瘤胃组织总RNA测定表皮生长相关基因表达量。结果表明：28日龄断奶组羔羊瘤胃乳头长度和宽度显著高于56日龄断奶组羔羊（P〈0.05）,瘤胃肌层厚度显著低于56日龄断奶组羔羊（P〈0.05）。断奶时间和羔羊日龄之间的交互作用对瘤胃乳头长度和肌层厚度有显著影响（P〈0.05）。28日龄断奶组羔羊瘤胃上皮胰岛素样生长因子结合蛋白（IGFBP）3、IGFBP5和IG FBP6表达量显著高于56日龄断奶组（P〈0.05）。羔羊瘤胃乳头长度与转化生长因子β（TGFβ）1和IGFBP6表达量呈显著负相关（r=-0.318,P=0.001;r=-0.520,P〈0.001）;瘤胃乳头宽度与TGFβ1表达量呈显著负相关（r=-0.275,P=0.004）,与IGFBP3和IGFBP5表达量呈显著正相关（r=0.344,P〈0.001;r=0.256,P=0.001）。综上所述,28日龄断奶促进湖羊羔羊瘤胃乳头发育和瘤胃表皮生长相关基因表达,可能参与羔羊瘤胃早期发育的调控。

英文摘要：

The objective of this study was to investigate the effects of weaner time on rumen morphology and gene expressions involved in rumen epidermis growth of Hu lambs at different days of age.Two-factor design was used,and the factors were weaner time and days of age of lambs.A total of 54 Hu lambs with similar birth weight [（3.51 ± 0.57） kg]were selected,and 6 of them were randomly selected and slaughtered on 28 days of age,while the remaining animals were randomly assigned to a 28 days of age weaner group [（8.21 ±0.97） kg] or a 56 days of age weaner group [（8.06 ± 0.53） kg].Six lambs from each group were randomly selected and slaughtered at 42,56,70 and 84 days of age,respectively.The ventral sac sample of rumen was collected to measure rumen papilla height,width and muscular thickness,and the tissue sample was extracted total RNA to measure gene expressions involved in rumen epidermis growth.The results showed as follows：rumen papilla height and thickness in 28 days of age weaner group was significantly higher than that in 56 days of age weaner group（P〈0.05）,however,rumen muscular thickness in 28 days of age weaner group was significantly lower than that in 56 days of age weaner group（P〈0.05）.There were significant interactions of weaner time and days of age for rumen papilla height and muscular thickness（P〈0.05）.The expressions of insulinlike growth factor binding protein（IG FBP） 3,IG FBP5 and IG FBP6 in 28 days of age weaner group were significantly higher compared with 56 days of age weaner group（P〈0.05）.Rumen papilla length was negatively correlated with expressions of IG FBP6 and transforming growth factor β（TG Fβ） 1（r =-0.318,P = 0.001;r =-0.520,P〈 0.001）;rumen papilla width was negatively correlated with the expression of TG Fβ1（r =-0.275,P = 0.004）,while were positively correlated with expressions of IG FBP3 and IG FBP5（r = 0.344,P 0.001;r = 0.256,P = 0.001）.In conclusion,the results indicate that weaning at 28 days of age can promote rumen p