The experiment was conducted to investigate the effect of dietary digestible energy (DE) levels on performance, lipid metabolism and lipoprotein lipase (LPL) gene expression in fat and muscle tissues of China Rongchang strain' s roast sucking pigs. A total of 72 healthy weanling piglets with average body weight of (4.95 ±0. 78) kg were randomly allotted to 4 treatments with 3 replicates per treatment and 6 pigs per replicate. Piglets were fed with 4 formulated diets contained 13.39, 14.23, 15.06 and 15.90 MJ/kg DE, respec tively. The experiment lasted for 28 d. For this experiment, these indices were determined such as performance, concentrations of lipids in serum, LPL and malate dehydrogenase (MDH) activity in longissimus dorsi (LM), and LPL mRNA expression in muscle and fat tissues. The results showed as follows; 1) there was a significant quadratic increase in average daily gain (ADG) as dietary DE level increased (P <0.05); the ratio of feed and gain (F/G) decreased linearly along with the increasing of dietary DE level (P <0.05). 2) The concentration of total triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) in serum increased linearly (P<0.01) as dietary DE level increased, however, there were no significant differences observed in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and non-esterified fatty acids (NEFA) a mong the groups (P >0.05). 3) Increasing dietary DE level resulted in a linear increase of MDH activity in LM (P <0.01), but there was no effect detected in LPL activity (P >0.05); in addition, increasing dietary DE level linearly enhanced the expression of LPL mRNA in adipose tissues (P <0.01). 4) The expression of LPL mRNA in LM was not affected by the increasing of dietary DE level. The results indicate that dietary DE levels affect performance and blood lipid concentrations, modified the activities of enzymes involved in lipid metabolism and the expressions of related genes, then finally affect body fat deposition to some degree, and modified the meat quality of China Rongchang strain' s roast sucking pigs.%本文旨在探讨饲粮消化能水平对荣昌烤乳猪品系生产性能、脂肪代谢及脂肪和肌肉组织中脂蛋白脂酶(LPL)基因表达量的影响.试验选用72头初始体重(4.95±0.78) kg的健康荣昌烤乳猪品系断奶仔猪,随机分为4个处理,每个处理3个重复,每个重复6头猪.各处理分别饲喂消化能水平分别为13.39、14.23、15.06和15.90 MJ/kg的试验饲粮,试验期共28 d.分别测定该品系仔猪的生产性能、血脂水平、背最长肌中LPL和苹果酸脱氢酶(MDH)的活性,以及背肌和背脂中LPL mRNA的表达量.结果表明:1)饲粮消化能水平与仔猪平均日增重(ADG)间呈显著二次曲线变化(P＜0.05),料重比随饲粮消化能水平的增加而呈线性降低(P＜0.05).2)随着饲粮消化能水平的提高,仔猪血清总甘油三酯(TG)和高密度脂蛋白胆固醇(HDL-C)的含量呈线性增加(P＜0.01),但对血清总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、游离脂肪酸(NEFA)含量无显著影响(P＞0.05).3)仔猪背最长肌中MDH活性随饲粮消化能水平的提高呈线性增加(P＜0.01),但饲粮消化能水平对背最长肌中LPL的活性影响不显著(P＞0.05).4)仔猪背脂中LPL mRNA表达量随饲粮消化能水平的提高呈线性增加(P＜0.01),但饲粮消化能水平对仔猪背最长肌LPL mRNA表达量无显著影响(P＞0.05).以上结果表明,饲粮消化能水平可影响荣昌烤乳猪品系仔猪生产性能及血脂水平,改变脂肪代谢酶的活性及其相关基因的表达,进而在一定程度上影响荣昌烤乳猪品系仔猪体脂沉积,改善肉品质.
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