Stressful situations, such as weaning and transport, are known to impact beef cattle health and performance. Hence, alternatives to minimize these stress-related losses are warranted and the bovine appeasing substance (BAS) is expected to have calming effects in cattle going through stressful events. Therefore, 2 studies were designed to investigate the impacts of BAS administration at weaning (Experiment 01) and immediately prior to transport to slaughter in beef animals (Experiment 02). In Experiment 01, 120 Bos indicus-influenced calves were weaned at 7 mo of age (day 0). At weaning, calves were ranked by BW and assigned to receive BAS (Nutricorp; Araras, SP, Brazil; n = 60) or water (CON; n = 60). Treatments (5-mL) were topically applied to the nuchal skin area of each animal. Calf body weight (BW) was recorded twice on days 0, 14, and 45 of the study. Calves that received BAS were heavier than CON cohorts at the end of the experimental period (P < 0.01). Additionally, starting on day 14, calves that received BAS had a greater average daily gain (ADG) when compared to CON cohorts (P ≤ 0.01). In Experiment 02, a total of 835 Nelore-influenced animals, originated from 4 farms were used herein. Immediately prior to transport, animals were ranked by BW and assigned to receive BAS (n = 422) or water (CON; n = 413). Treatments (5 mL) were applied as previously described for Experiment 01. For all animals transported, meat pH was determined from the 12^th rib 48 hours post-mortem. Animals having a meat pH > 5.80 were classified as higher-risks for having dark, firm, and dry (DFD) and was further evaluated herein. Additionally, for animals originated from farm 1 (n = 59), a portion of the Longissimus dorsi muscle was collected for colorimetric analysis. A treatment effect was detected for meat pH (P < 0.0001), so that animals receiving BAS had a reduced pH vs. CON cohorts (5.75 vs. 5.82, respectively). Additionally, the risk of DFD% was greater (P < 0.0001) for CON vs. BAS when pH > 5.80 (42.2 vs. 26.2%, respectively) was evaluated. In summary, BAS administration to animals prior to stressful events (weaning and transport to slaughter) improved performance, decreased the risk if occurrence of DFD cuts, and maintained the pH at levels below the threshold considered as critical for DFD occurrence.

断奶和运输等压力大的状况会影响肉牛的健康和性能。因此，必须采取替代措施以尽量减少这些与压力有关的损失，并且预计牛易感物质（BAS）对经历压力事件的牛具有镇定作用。因此，设计了2项研究来研究断奶时（实验01）以及即将运输到屠宰场的牛肉中BAS施用的影响（实验02）。在实验01中，在7mo龄（第0天）断奶了120只受Bos indicus影响的犊牛。断奶时，犊牛按体重排序，并分配给其接受BAS（Nutricorp；巴西阿拉拉斯，SP； n = 60）或水（CON; n = 60）。将治疗剂（5-mL）局部施用于每只动物的颈部皮肤区域。在研究的第0、14和45天记录两次小腿体重（BW）。在实验期结束时，接受BAS的犊牛比CON队列重（P  <0.01）。此外，从第14天开始，与CON组相比，接受BAS的小牛的平均日增重（ADG）更高（P ≤0.01）。在实验02中，总共使用了来自4个农场的835只受Nelore影响的动物。在运输之前，立即按照体重对动物进行排名，并指定其接受BAS（n = 422）或水（CON； n = 413）。如先前针对实验01.描述对于输送所有动物施用治疗（5毫升），肉的pH从12确定^第肋48小时后验。肉的pH值> 5.80的动物因肤色暗，坚硬和干燥（DFD）而被归类为较高风险，在此进行了进一步评估。此外，对于源自农场1（n = 59）的动物，收集了部分背长肌以进行比色分析。检测到肉类pH值有治疗效果（P <0.0001），因此接受BAS的动物的pH值相对于CON组降低（分别为5.75和5.82）。此外，当评估 pH> 5.80（分别为42.2 vs. 26.2％）时，CON相对于BAS的DFD％风险更大（P <0.0001）。总之，在应激事件（断奶和运输到屠宰）之前向动物施用BAS可以改善性能，降低发生DFD割伤的风险，并使pH值保持在对于DFD发生至关重要的阈值以下。