Rosenvold K, Petersen J S, Lwerke H N, Jensen S K, Therkildsen M, Karlsson A H, Møller H S, Andersen H J
Department of Animal Product Quality, Danish Institute of Agricultural Sciences, Tjele.
J Anim Sci. 2001 Feb;79(2):382-91. doi: 10.2527/2001.792382x.
The aim of the present study was to investigate whether muscle glycogen stores in slaughter pigs could be decreased through strategic finishing feeding before slaughter. Moreover, preliminary meat quality traits were measured to see whether such a regulation of muscle glycogen stores affected ultimate pH, color, and tenderness in the meat. The strategic finishing feeding was carried out the last 3 wk prior to slaughter. Seven experimental groups with eight animals per group were fed diets low in digestible carbohydrates. A control group with four animals was fed a traditional grower-finishing diet. The muscle glycogen stores were reduced in longissimus muscle (LM) 11 to 26% at the time of slaughter in pigs that were fed the experimental diets compared with the control group. Meat quality measured as ultimate pH and color on LM muscle in half the pigs 24 h postmortem showed that ultimate pH in LM was not affected by the reduction in glycogen stores in the muscles from pigs fed any of the experimental diets. However, the meat from pigs fed the experimental diets was darker than the meat from pigs that were fed the control diet with two of the experimental diets, resulting in significantly lower L* values. Activities of key enzymes in the glycolytic pathway, glycogen phoshorylase a and b, phosphofructokinase, and the fatty acid oxidative pathway, beta-hydrozyacyl-CoA-dehydrogenase, were not affected by the strategic feeding. In contrast, the activity of the proteolytic enzyme calpain as well as its inhibitor calpastatin was influenced by the strategic feeding. Lower activity of mu-calpain and greater activity of calpastatin in the muscle samples from the strategically fed pigs indicate a lesser muscle protein degradation in the muscles compared with muscles of control animals. The present study showed that the muscle glycogen stores in slaughter pigs can be reduced at the time of slaughter through strategic finishing feeding with diets low in digestible carbohydrate without compromising growth rate.
本研究的目的是调查屠宰前通过策略性育肥饲养是否可以降低屠宰猪的肌肉糖原储备。此外，还测定了初步的肉质性状，以观察这种对肌肉糖原储备的调节是否会影响肉的最终pH值、颜色和嫩度。策略性育肥饲养在屠宰前的最后3周进行。七个实验组，每组八只动物，饲喂低消化碳水化合物的日粮。一个对照组，四只动物，饲喂传统的生长育肥日粮。与对照组相比，饲喂实验日粮的猪在屠宰时，背最长肌（LM）的肌肉糖原储备减少了11%至26%。在半数猪宰后24小时，以LM肌肉的最终pH值和颜色衡量的肉质表明，饲喂任何一种实验日粮的猪，其肌肉中糖原储备的减少并未影响LM的最终pH值。然而，饲喂实验日粮的猪的肉比饲喂对照日粮的猪的肉颜色更深，其中两种实验日粮的猪的肉L*值显著更低。糖酵解途径中的关键酶糖原磷酸化酶a和b、磷酸果糖激酶，以及脂肪酸氧化途径中的β-羟酰基辅酶A脱氢酶的活性不受策略性饲养的影响。相反，蛋白水解酶钙蛋白酶及其抑制剂钙蛋白酶抑制蛋白的活性受策略性饲养的影响。与对照动物的肌肉相比，策略性饲养猪的肌肉样本中μ-钙蛋白酶活性较低，钙蛋白酶抑制蛋白活性较高，这表明肌肉中的肌肉蛋白降解较少。本研究表明，通过饲喂低消化碳水化合物的日粮进行策略性育肥饲养，可以在屠宰时降低屠宰猪的肌肉糖原储备，而不影响生长速度。
