摘要
One hundred and thirty six Angus steers were used to evaluate the effects of feedlot placement weight (PW; weight of the animal at the time of its placement into the feedlot) and days on feed (DOF) on feed efficiency, carcass transfer (CT), and carcass traits. The 2 × 4 factorial experiment included PW (Light (LT), 310 kg BW; or Heavy (HV), 415 kg BW) and DOF (54, 83, 111, or 145 d) before slaughtering. At d 0, four steers selected at random from each PW group were slaughtered to determine initial hot carcass weight (HCW). The rest of the steers were allocated in pens (4 pens/treatment; 4 steers/pen) with ad libitum access to feed and drinking water. No PW × DOF interactions were detected for any response variables (P > 0.05). Heavy steers showed greater (P < 0.001) daily dry matter intake (DMI) than LT steers. Daily DMI did not change (P = 0.11) across DOF. Average daily gain (ADG) and daily carcass weight gain (CWG) were not affected (P > 0.05) by PW. Although ADG showed a quadratic (P = 0.003) response across DOF, CWG was higher (P < 0.05) for steers fed 83 d or longer. This resulted in a linear increase (P < 0.001) in CT (ratio of CWG to ADG, expressed as a percentage) during the 145 feeding period. Feed efficiency (DMI: ADG and DMI: CWG ratios) was better (P < 0.001) for LT than HV steers. The ratio DMI: ADG was higher (P < 0.05) for 145 DOF steers, whereas the ratio DMI: CWG tended (P = 0.08) to be better for 111 DOF. Heavy steers showed greater (P < 0.05) final live weight, HCW, ribeye area, subcutaneous fat thickness, and marbling score than LT steers. Final weight and HCW increased linearly (P < 0.001) with DOF. Subcutaneous fat thickness was higher (P < 0.05) for steers fed 111 d or longer. Marbling score and LM total lipid increased linearly (P < 0.001) with DOF. Longissimus muscle pH and color (a*, b*), and subcutaneous fat color (L*, a*, b*) were not affected (P > 0.05) by treatments. Warner Bratzler shear force did not differ (P = 0.16) between PW but was affected (P = 0.005) by DOF. However, all steaks showed a WBS value below 4.0 kg. Regardless of treatment, WBS decreased (P < 0.001) as postmortem aging days increased. Overall, HV steers produced larger carcasses that had greater fat deposition, and similar tenderness than LT steers. Feeding up to 111 days, regardless PW, could improve animal performance and CT, and produce large carcasses with acceptable levels of subcutaneous fat thickness and palatable beef.
摘要译文
使用一百三十六个安格斯操纵者来评估饲养仪放置重量的影响（PW;将动物的重量在其放置到饲料时的饲料（DOF）上的饲料效率，胴体转移（CT）和胴体性状。 2×4因子实验包括PW（光（LT），310千克BW;在屠宰前或重度（HV），415千克BW）和DOF（54,83,111或145d）。在D 0中，屠宰了从每个PW组随机选择的四个操纵器以确定初始热胴体重量（HCW）。其余的操纵器被分配在钢笔（4张钢笔/治疗; 4个Steers / Pen）与广告采访饲料和饮用水。没有检测到任何响应变量的PW×DOF相互作用（P> 0.05）。重型带状器显示出大（P <0.001）日常干物质摄入（DMI）而不是LT Steers。每日DMI在DOF中没有改变（p = 0.11）。平均每日增益（ADG）和每日胴体重量增益（CWG）未受影响（P> 0.05）。虽然ADG在DOF上显示了二次（P = 0.003）响应，但是对于输入83d或更长的带状器，CWG更高（P <0.05）。在145次进料期间，这导致CT（CWG与ADG的比率为百分比表示为百分比）的线性增加（P <0.001）。饲料效率（DMI：ADG和DMI：CWG比率）比HV操纵器更好（P <0.001）。比率DMI：ADG更高（P <0.05），适用于145个DOF操纵器，而比率DMI：CWG趋于（P = 0.08），为111 DOF更好。重型阉圈显示出更大（P <0.05）最终的活体重，HCW，Ribeye区域，皮下脂肪厚度和大理石大理石比得分而不是LT Steers。最终的重量和HCW用DOF线性增加（P <0.001）。对于进料111d或更长的带状器，皮下脂肪厚度较高（P <0.05）。用DOF线性增加肌肉pH和颜色（A *，B *）和皮下脂肪颜色（L *，a *，b *）未受处理（p> 0.05）。 Warner Bratzler剪切力在PW之间没有区别（P = 0.16），但受到DOF的影响（p = 0.005）。然而，所有牛排都显示出低于4.0千克的WBS值。无论治疗如何，随着淘汰的老化日增加，WBS减少（P <0.001）。总体而言，HV操纵器产生较大的胴体，其具有更大的脂肪沉积，以及比LT Steers更高的温柔。无论pW，喂养最多111天，可以改善动物的性能和CT，并产生具有可接受的皮下脂肪厚度和可口牛肉水平的大屠体。
GabrielaVolpi-Lagreca[a];Lucas F.Gelid[a];MarianoAlende[a];Elbio R.Bressan[b];Adriana B.Pordomingo[a];Anibal J.Pordomingo[a];. Effect of placement weight and days on feed on feedlot cattle performance and carcass traits - ScienceDirect[J]. Livestock Science, 2021,244