Cooke Reinaldo F, Mackey Shea J, de Souza Izadora S, Mello Ingo A S, Barreto Yasmin M, Gouvea Vinicius N
Department of Animal Science, Texas A&M University, College Station, TX 77843, USA.
Ourofino Saúde Animal, Cravinhos, SP 14140-000, Brazil.
Transl Anim Sci. 2025 Feb 11;9:txaf022. doi: 10.1093/tas/txaf022. eCollection 2025.
Two experiments evaluated growth performance of finishing cattle placed on feed as yearlings, and receiving the maternal bovine appeasing substance () during stressful management events. In Exp. 1, 240 Angus-influenced yearling steers arrived at the research feedyard on d -1 after a 4-h road transport, and body weight () was recorded upon arrival (411.8 ± 2.5 kg). Steers were ranked by arrival BW and received 1 of 2 treatments during initial processing (d 0): 1) 10 mL of a mBAS (Ferappease; FERA Diagnostics and Biologicals; College Station, TX) or 2) 10 mL of mineral oil (; placebo). Treatments were applied topically to the nuchal skin area (5 mL) and above the muzzle (5 mL). During initial processing, steers were weighed, vaccinated against spp. and respiratory pathogens, dewormed, implanted, and then distributed into 30 drylot pens according to arrival BW and treatment (n = 15 pens/treatment, 8 steers/pen). Steers were reapplied treatments concurrently with reimplanting on d 75. Initial BW was the average BW on d -1 and 0, final BW was the average of BW recorded on d 138 and 139, and steers were slaughtered on d 139. Steers assigned to mBAS had greater (≤ 0.04) ADG, final BW, and hot carcass weight (). Feed intake was greater (≤ 0.05) in mBAS steers, but mostly after reimplanting (treatment × day; < 0.01). Carcass yield grade, backfat thickness, marbling score, and % Choice or better were greater (≤ 0.05) in mBAS steers. In Exp. 2, Nelore () yearling bulls (n = 2,626) arrived at a feedyard (d 0) after a 96-h road transport, and BW was recorded upon arrival (shrunk BW = 352.9 ± 0.6 kg). Bulls were assigned to receive mBAS or CON as in Exp. 1 during initial processing on d 0 (10 pens/treatment; ~130 bulls/pen) which included deworming and vaccination against spp. and respiratory pathogens. Bulls were on feed for 96.0 ± 1.0 d until slaughter. Bull ADG was calculated using arrival BW considering a 14% shrink and final BW recorded when loading bulls to slaughter. Bulls assigned to mBAS had greater (≤ 0.04) ADG, feed intake, final BW, and HCW. Morbidity and mortality rates due to respiratory disease were less (= 0.02) in mBAS bulls. Collectively, mBAS administration during stressful management events improved growth performance, mainly by increasing feed intake, in finishing cattle placed on feed as yearlings in feedlot systems typical of US (Exp. 1) and tropical regions (Exp. 2).
两项试验评估了作为一岁牛开始育肥且在应激管理事件期间接受母体牛安抚物质（ ）的育肥牛的生长性能。在试验1中，240头受安格斯牛影响的一岁公牛在经过4小时公路运输后于第-1天抵达研究饲养场，抵达时记录体重（ ）（411.8±2.5千克）。公牛按抵达时的体重进行排名，并在初始处理（第0天）期间接受两种处理之一：1）10毫升母体牛安抚物质（Ferappease；FERA诊断与生物制品公司；德克萨斯州大学站）或2）10毫升矿物油（ ；安慰剂）。处理剂局部施用于颈部皮肤区域（5毫升）和口鼻上方（5毫升）。在初始处理期间，对公牛称重、接种针对 属细菌和呼吸道病原体的疫苗、驱虫、植入生长激素埋植剂，然后根据抵达时的体重和处理方式将其分配到30个干栏式畜栏中（每个处理15个畜栏，每个畜栏8头公牛）。在第75天重新植入生长激素埋植剂时同时再次施用处理剂。初始体重为第-1天和第0天的平均体重，最终体重为第138天和第139天记录体重的平均值，公牛在第139天屠宰。分配到母体牛安抚物质处理组的公牛平均日增重（ADG）、最终体重和热胴体重更高（ ≤0.04）。母体牛安抚物质处理组的公牛采食量更大（ ≤0.05），但主要是在重新植入生长激素埋植剂之后（处理×天数； ＜0.01）。母体牛安抚物质处理组的公牛胴体产肉等级、背膘厚度、大理石花纹评分以及优质肉（特级及以上）比例更高（ ≤0.05）。在试验2中，2626头内洛雷（ ）一岁公牛在经过96小时公路运输后于第0天抵达一个饲养场，抵达时记录体重（收缩体重=352.9±0.6千克）。公牛在第0天的初始处理期间（每个处理10个畜栏；每个畜栏约130头公牛）被分配接受试验1中的母体牛安抚物质或对照处理，初始处理包括驱虫以及接种针对 属细菌和呼吸道病原体的疫苗。公牛育肥96.0±1.0天直至屠宰。公牛的平均日增重根据考虑14%体重收缩的抵达时体重和装载公牛屠宰时记录的最终体重来计算。分配到母体牛安抚物质处理组的公牛平均日增重、采食量、最终体重和热胴体重更高（ ≤0.04）。母体牛安抚物质处理组的公牛因呼吸道疾病导致的发病率和死亡率更低（ =0.02）。总体而言，在应激管理事件期间施用母体牛安抚物质改善了生长性能，主要是通过增加采食量，这在典型的美国饲养场系统（试验1）和热带地区（试验2）中作为一岁牛开始育肥的育肥牛中得到体现。
