Geesink G H, Smulders F J, van Laack H L, van der Kolk J H, Wensing T, Breukink H J
Department of The Science of Food of Animal Origin, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.
J Anim Sci. 1993 May;71(5):1161-70. doi: 10.2527/1993.7151161x.
The objective of this study was to examine the effects of clenbuterol administration on meat quality traits of veal. Sixteen Holstein-Friesian veal calves (male) were randomly assigned to one of four treatment groups; either control (n = 4) or clenbuterol-treated (1.6 micrograms.kg [corrected] BW-1.d-1, 42 d) with a withdrawal period between clenbuterol treatment and slaughter of 8 d (n = 4), 4 d (n = 4), or 2 d (n = 4). All animals were slaughtered at the same day at a commercial slaughterplant. At 30 min postmortem the carcasses were split and the right carcass side was electrically stimulated. After 24 h of cooling the longissimus, semimembranosus, triceps brachii, and psoas major muscles were excised and vacuum-packaged. After 1, 7, and 13 d of vacuum storage at 2 +/- 2 degrees C the muscles were sampled to determine tenderness, water-holding capacity, and color characteristics. Clenbuterol treatment resulted in a slower rate of pH decline in the unstimulated longissimus muscle but did not affect the ultimate pH. Clenbuterol treatment resulted in toughening of the longissimus, semimembranosus, and triceps brachii muscles after 1 and(or) 7 d of storage (P < .05). It is suggested that this resulted from a decrease in postmortem proteolysis because both the intensity of a 30-kDa peptide and the myofibril fragmentation index were lower in clenbuterol-treated muscles. Clenbuterol treatment resulted in increased lightness (L*-value) of longissimus and semimembranosus muscles (P < .05), coincident with a lower water-holding capacity. In a following experiment, the effect of clenbuterol administration (0 [n = 5] and 1.0 [n = 5] mg/kg of feed for 27 d) on calpain and calpastatin levels at 1 d postmortem in longissimus muscles of Friesian Pie Noire veal calves was investigated. Clenbuterol administration resulted in an increase in calpastatin levels (P < .05) and a trend (P < 0.1) toward a decrease in mu-calpain activity at 1 d postmortem.
本研究的目的是检测克伦特罗给药对小牛肉肉质性状的影响。16头荷斯坦 - 弗里生小牛肉犊牛（雄性）被随机分配到四个处理组之一；对照组（n = 4）或用克伦特罗处理（1.6微克·千克[校正后]体重-1·天-1，持续42天），在克伦特罗处理和屠宰之间设置8天（n = 4）、4天（n = 4）或2天（n = 4）的停药期。所有动物于同一天在一家商业屠宰场屠宰。宰后30分钟将胴体劈开，右侧胴体进行电刺激。冷却24小时后，切除背最长肌、半膜肌、肱三头肌和腰大肌并进行真空包装。在2±2℃下真空储存1、7和13天后，对肌肉进行取样以测定嫩度、持水力和颜色特征。克伦特罗处理导致未刺激的背最长肌pH值下降速率减慢，但不影响最终pH值。克伦特罗处理导致储存1天和（或）7天后背最长肌、半膜肌和肱三头肌肌肉变韧（P <.05）。这表明这是由于宰后蛋白水解减少所致，因为在克伦特罗处理的肌肉中，30 kDa肽的强度和肌原纤维破碎指数均较低。克伦特罗处理导致背最长肌和半膜肌肌肉亮度（L*值）增加（P <.05），同时持水力降低。在接下来的实验中，研究了克伦特罗给药（0 [n = 5]和1.0 [n = 5]毫克/千克饲料，持续27天）对弗里西安黑派小牛肉犊牛背最长肌宰后1天钙蛋白酶和钙蛋白酶抑制蛋白水平的影响。克伦特罗给药导致宰后1天钙蛋白酶抑制蛋白水平升高（P <.05），并且μ-钙蛋白酶活性有降低的趋势（P < 0.1）。
