宰前短期高钙日粮对猪肌钙含量和μ-calpain活性及其mRNA表达量的影响

Effects of High Dietary Calcium within Short Term Feeding on Muscular Calcium Content,Activity and mRNA Expression of μ-calpain of Swines

本试验以松辽黑猪为试验对象,研究宰前短期高钙日粮对猪肌钙含量和μ-calpain活性及其mRNA表达量的影响。选取健康、初重为(90.2±2.8)kg的松辽黑猪48头,随机分成8组,每组6个重复,每个重复1头猪。试验期为7 d。对照组饲喂基础日粮,试验组日粮分别在基础日粮中添加Ca^(2+)浓度为0、0.5%、1.0%和1.5%的CaCl_2或甲酸钙。结果表明:与对照组相比,CaCl_2和甲酸钙均可显著(P<0.05)或极显著(P<0.01)提高肌钙含量和μ-calpain活性,其中以1.0%甲酸钙组效果最明显;甲酸钙可以提高μ-calpain的mRNA相对表达量,1.0%甲酸钙组与其他各组差异显著(P<0.05);甲酸钙处理下,肌钙与μ-calpain在宰后熟化第3天和第9天存在着显著的正相关(P<0.05)。由结果可知,CaCl_2和甲酸钙做为宰前肥育猪日粮中短期超量添加的钙源,均可达到提高肌钙含量和μ-calpain活性的目的,在本试验条件下以1.0%的甲酸钙(以Ca^(2+)浓度计)效果最好。

This trial was conducted to study the effects of high dietary calcium within short term feeding on muscular calcium content, activity and mRNA expression of μ-calpain of Songliao black swines. Forty-two Songliao black swines with an initial weight of （90.2 ± 2.8） kg were randomly allotted to 8 groups with 6 replicates each and 1 swine in each replicate. The trial lasted for 7 days. The control group was fed basal diets （contained Ca^2＋ of 0.5%, without CaCl2 and calcium formate）, the experimental groups were fed＇basal diets with 0, 0.5%, 1.0% and 1.5% CaCl2 and calcium formate, respectively. The results showed as follows： compared with control group, CaC12 and calcium formate increased the content of muscular calcium and activity of μ-calpain （P〈0.05）, and 1.0% calcium formate group had the best effect; calcium formate could increase the relative expression of μ-calpain mRNA, and the relative expression of μ-calpain mRNA of 1.0% calcium formate group was significantly higher than those of other groups （P〈0.05）. There was a significant positive relation between muscular calcium and activity of μ-calpain under the treatment of calcium formate after 3 d and 9 d of slaughtering （P〈0.05）. In conclusion, calcium chloride and calcium formate as the source of calcium in short term feeding of finishing pigs before slaughter could increase the content of muscular calcium and activity of μ-calpain, and the 1.0% calcium formate group had the best effect in this research.