【作者】 程善燕；

【导师】 张英杰；

【作者基本信息】 河北农业大学 ， 动物营养与饲料科学， 2010， 硕士

【摘要】 选用健康无病,4月龄体重相近的F2代杂交母羊(道赛特♂×小尾寒羊♀)36只,随机分为A组(低能量组)、B组(中能量组)、C组(高能量组)3组,每组12只。B组为对照组,按照美国NRC(1985)肉羊饲养标准中的能量需要量设计的日粮饲喂,代谢能为10.32 MJ/d,A组和C组处理是在中等能量水平基础上减少和增加30%:即低能量水平(A组)代谢能为7.21 MJ/d,高能量水平(C组)代谢能为13.48MJ/d,各处理组蛋白质及其它营养指标基本保持一致。饲喂50天后从每个试验组中随机选取6只绵羊进行屠宰,测其宰前活重、胴体重、屠宰率、背膘厚,屠宰后取两侧背最长肌(第12肋骨),后腿股二头肌测肌内脂肪含量。宰后立即取背最长肌、股二头肌、心脏及皮下脂肪组织样品,用于提取总RNA,通过优化反应条件和体系,采用实时荧光定量PCR方法对激素敏感脂肪酶(HSL)基因在背最长肌、股二头肌、心脏及皮下脂肪组织中的表达量进行了检测。同时分析了三个能量水平日粮对绵羊HSLmRNA绝对表达量的影响。试验结果如下:1低能量组试验羊的宰前活重、胴体重、屠宰率显著低于中能量和高能量组(P<0.01或P<0.05),中能量组与高能量组的屠宰性能差异不显著(P>0.05);低能量组试验羊的背膘厚极显著低于中能量、高能量组(P<0.01),中能量组和高能量组之间差异也极显著(P<0.01)。低能量组试验羊背最长肌及股二头肌肌内脂肪含量极显著低于中能量、高能量组(P<0.01),中能量组和高能量组之间差异也极显著(P<0.01)。2日粮的能量水平影响绵羊皮下脂肪组织、背最长肌、股二头肌和心脏HSL基因的表达,随着日粮能量水平的升高,HSLmRNA表达量减少;在皮下脂肪中三组能量水平之间的HSLmRNA绝对表达量差异极显著(P<0.01),低能量组显著高于中、高能量组的表达;在背最长肌、股二头肌中的表达低能量组与中、高能量组比较差异极显著(P<0.01),中能量与高能量组之间差异显著(P<0.05);在心脏中的表达中能量组与低、高能量组之间均差异显著(P<0.05),低能量组极显著高于高能量组(P<0.01)。3 HSL基因在绵羊脂肪组织、背最长肌、股二头肌和心脏的表达具有组织特异性,在脂肪组织表达量最高,心脏的表达量最低,脂肪组织表达量极显著高于背最长肌、股二头肌和心脏的表达量(P<0.01),另外在肌肉组织中背最长肌的表达量高于股二头肌。更多还原

【Abstract】 Choose healthy disease-free, 4 months old F2 generation of hybrids with similar weight crossbred ewes (Dorset sheep♂×Small Tail Han Sheep♀) ,which were randomly divided into 3 groups of 12,including group A (low-energy group), group B (middle-energy group),group C (high-energy group).As the control group,Group B was raised according to the energy requirement of American NRC(1985) Meet Sheep Feeding Standard, the energy level of metabolic energy group was 10.33 MJ / d, group A and group C based on middle-energy group on the reduction and increase of 30%,separately: that is, metabolizable energy of low energy level (group A) was 7.21 MJ / d, metabolizable energy of high energy level (group C) was 13.49 MJ / d, indicators of protein and other nutrients remained the same. After 50 days feeding, selected six sheep from each experimental group randomly and slaughtered, slaughter live weight,carcass weight,dressing percentage and backfat thickness were measured before slaughter, slaughter on both sides of longissimus muscle (12 ribs) and hind legs biceps femoris were obtained for intramuscular fat content. Longissimus, biceps femoris, heart and the subcutaneous adipose tissue samples were taken in the shortest time for extraction of total RNA. By optimizing the reaction conditions, using real time quantitative PCR method detected hormone-sensitive lipase (HSL) gene in longissimus, biceps femoris, heart and subcutaneous adipose tissue expression. The three energy levels effects on sheep HSL mRNA expression was analyzed. The results are as follows:1. Experimental sheep of the low-energy group before the slaughter live weight, carcass weight, dressing percentage of the low-energy group is significantly lower than that in the middle-energy group and the high-energy group (P<0.01 or P<0.05). The slaughter performance between the middle- energy group and the high-energy group was not significant difference (P>0.05); the sheep’s back fat thickness, longissimus muscle and biceps femoris within the fat content of intramuscular fat content of the low-energy group was significantly lower than that in the middle-energy group and the high- energy group (P<0.01), the energy difference between the middle-energy group and the high-energy group were also significantly (P<0.01).The longissimus muscle shear force of high-energy group was significantly lower than the middle-energy group and the low energy group (P <0.01); The two head muscle shear force of the high-energy group was significantly lower than the low energy group (P <0.01).2. The expression of HSL mRNA decreased with the levels of dietary energy increased in longissimus muscle, biceps femoris, heart and subcutaneous adipose tissue;the absolute expression of HSL mRNA during the three groups in abdominal subcutaneous fat was significant difference (P<0.01), the expression in the low-energy group was significantly higher than the middle-energy group and the high-energy group expression; compared with the high-energy group, the expression in longissimus, biceps femoris of the low-energy group was significant difference (P<0.01), the energy difference between the middle-energy group and the high-energy group was significantly (P<0.05); the expression in the heart of the middle-energy group was significantly difference with the low-energy group and the high-energy group(P <0.05), and the low-energy group was significantly higher than the high-energy group (P <0.01).3. HSL gene in sheep adipose tissue, longissimus muscle, biceps femoris and heart tissue was expressed specificly, its expression in adipose tissue was highest and the lowest in the heart. The expression of in adipose tissue was significantly higher than in the longissimus muscle, biceps femoris, and heart (P<0.01).Besides, the expression of longissimus in muscle tissue was higher than in biceps femoris.更多还原