Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana 61801, USA.
J Anim Sci. 2009 Nov;87(11):3730-8. doi: 10.2527/jas.2009-1838. Epub 2009 Jul 31.
The objective of these studies was to evaluate the effects of zilpaterol hydrochloride (ZH), fed for 0, 20, or 30 d, on meat quality attributes of calf-fed Holstein steers. Steers were slaughtered at a commercial facility, and carcasses were selected by HCW to represent the pen mean. Further carcass selection was based on quality grade (Choice and Select) and yield grade. Proximate composition, measures of water holding capacity, and tenderness using Warner-Bratzler shear force after 7, 14, or 21 d postmortem were evaluated on the shoulder clod (triceps brachii), top butt (gluteus medius), and strip loin (longissimus lumborum). Percentage of purge for the 3 subprimals was not different (P > 0.05) among ZH treatments. Steers fed ZH for 20 d or 30 d had decreased (P < 0.05) percentages of fat in the triceps brachii, compared with 0-d ZH. Percentage of fat was less (P < 0.05) in the gluteus medius and longissimus lumborum when steers were fed ZH for 30 d compared with those steers fed ZH for 0 d. Percentage of fat was greater in Choice triceps brachii (P < 0.05) and longissimus lumborum (P < 0.10) compared with Select. Thaw loss was not different (P > 0.05) for any muscle due to ZH treatment. Only longissimus had a greater (P < 0.05) cooking loss with ZH treatment. Cooking loss was not different (P > 0.05) for the gluteus medius or longissimus lumborum due to quality grade or aging day. At each aging day, the 20- and 30-d ZH longissimus lumborum had greater (P < 0.05) shear force values than 0 d; however, 20- and 30-d ZH had a greater absolute change in shear force from 7 to 21 d than that of 0 d ZH. Triceps brachii steaks were less tender (P < 0.05) after ZH treatment, but gluteus medius steaks were not different (P > 0.05). There was no difference (P > 0.05) in shear force due to quality grade. Results illustrate the use of ZH in calf-fed Holstein steers will have minimal effects on purge, thaw, or cooking loss. Percentage of intramuscular fat will decrease, especially when fed for longer durations. Steaks from ZH treated steers were tougher than steaks from control animals at all aging times, but ZH steaks became more tender with postmortem aging.
这些研究的目的是评估盐酸齐帕特罗（ZH）的作用，其在 0、20 或 30 天内被喂食，对荷斯坦犊牛育肥牛的肉质属性的影响。牛在商业设施中被屠宰，胴体通过 HCW 选择以代表栏位平均值。进一步的胴体选择基于质量等级（Choice 和 Select）和产肉等级。在 7、14 或 21 天的死后，对三角肌（肱三头肌）、顶臀（臀中肌）和里脊（腰大肌）进行近侧成分、水分保持能力测量和嫩度评估使用 Warner-Bratzler 剪切力。3 个次级切割品的汁液损失百分比在 ZH 处理之间没有差异（P>0.05）。与 0 天 ZH 相比，20 天或 30 天 ZH 处理的牛的三角肌中脂肪百分比降低（P<0.05）。与 0 天 ZH 相比，30 天 ZH 处理的牛的臀中肌和腰大肌中的脂肪百分比降低（P<0.05）。Choice 三角肌（P<0.05）和腰大肌（P<0.10）中的脂肪百分比大于 Select。由于 ZH 处理，三角肌的解冻损失（P>0.05）和里脊没有差异。由于质量等级或老化天数，臀中肌或腰大肌的烹饪损失没有差异（P>0.05）。在每个老化日，20 天和 30 天 ZH 里脊的剪切力值均大于 0 天；然而，20 天和 30 天 ZH 与 0 天 ZH 相比，从 7 天到 21 天的剪切力绝对变化更大。在 ZH 处理后，三角肌牛排的嫩度降低（P<0.05），但臀中肌牛排没有差异（P>0.05）。由于质量等级，剪切力没有差异（P>0.05）。结果表明，在荷斯坦犊牛育肥牛中使用 ZH 将对清除、解冻或烹饪损失产生最小的影响。肌肉内脂肪百分比将降低，尤其是在较长时间内喂食时。在所有老化时间，来自 ZH 处理牛的牛排都比对照动物的牛排更坚韧，但 ZH 牛排随着死后老化变得更嫩。
