Carnagey K M, Huff-Lonergan E J, Lonergan S M, Trenkle A, Horst R L, Beitz D C
Department of Animal Science, Iowa State University, Ames, IA 50011, USA.
J Anim Sci. 2008 Jul;86(7):1637-48. doi: 10.2527/jas.2007-0406. Epub 2008 Mar 14.
The objective of this trial was to determine how 25-hydroxyvitamin D(3) (25-OH D(3)) supplementation, altering supplemental dietary calcium, or their combination influence postmortem biochemical and tenderness changes in muscles from the round of mature cows. Twenty-seven Angus cows (3 to 7 yr old) were allotted randomly to 9 pens with 3 cows per pen. Treatments were arranged in a 3 x 3 factorial design with 3 dosages of 25-OH D(3) (0, 250, or 500 mg of 25-OH D(3) administered as a 1-time oral bolus 7 d before slaughter) and 3 percentages of supplemental limestone (0.5, 0.75, and 1.0%) replenished in the diet for 3 d before slaughter and after a 2-wk limestone withdrawal. Plasma samples were obtained during the feeding period. Upon slaughter, adductor, gracilus, pectineus, sartorius, semimembranosus, vastus intermedius, and vastus lateralis muscles were obtained and aged for 1, 3, or 7 d. Calcium concentrations were increased in plasma when 250 or 500 mg of 25-OH D(3) were administered (P </= 0.05). Calcium concentrations in muscle increased (P </= 0.001) when 500 mg of 25-OH D(3) were administered. Concentrations of 25-OH D(3) in meat and in plasma and 1,25-dihydroxyvitamin D(3) [1,25-(OH)(2) D(3)] in plasma were increased when 25-OH D(3) was administered (P </= 0.05). The percentage of limestone replenished in the diet had no effect on 25-OH D(3) or 1,25-(OH)(2) D(3) in meat or in plasma. Calpastatin activity was affected by treatments only in the gracilus and vastus intermedius muscles (P </= 0.05). Among all muscles and aging periods, calpastatin activity and intensity of troponin-T degradation product were related inversely. Results indicate that supplemental 25-OH D(3) has some influence on muscle characteristics known to improve tenderness, but improved tenderness was not observed.
本试验的目的是确定补充25-羟基维生素D₃（25-OH D₃）、改变补充膳食钙或二者联合使用如何影响成年母牛后腿肌肉的宰后生化变化和嫩度变化。27头安格斯母牛（3至7岁）被随机分配到9个栏中，每栏3头。处理采用3×3析因设计，有3种25-OH D₃剂量（0、250或500毫克25-OH D₃，在屠宰前7天一次性口服大剂量给药）和3种补充石灰石的比例（0.5%、0.75%和1.0%），在屠宰前3天及2周石灰石撤饲后添加到日粮中。在饲养期采集血浆样本。屠宰时，获取内收肌、股薄肌、耻骨肌、缝匠肌、半膜肌、股中间肌和股外侧肌，并熟化1、3或7天。给予250或500毫克25-OH D₃时，血浆钙浓度升高（P≤0.05）。给予500毫克25-OH D₃时，肌肉中的钙浓度升高（P≤0.001）。给予25-OH D₃时，肉和血浆中25-OH D₃的浓度以及血浆中1,25-二羟基维生素D₃[1,25-(OH)₂ D₃]的浓度升高（P≤0.05）。日粮中补充石灰石的比例对肉或血浆中的25-OH D₃或1,25-(OH)₂ D₃没有影响。钙蛋白酶抑制活性仅在股薄肌和股中间肌中受处理影响（P≤0.05）。在所有肌肉和熟化期，钙蛋白酶抑制活性与肌钙蛋白-T降解产物的强度呈负相关。结果表明，补充25-OH D₃对已知可改善嫩度的肌肉特性有一定影响，但未观察到嫩度改善。
