Ziegler Robert L, Musgrave Jacki A, McCarthy Kacie L, Travis Mulliniks J
West Central Research and Extension Center, University of Nebraska, North Platte, NE 69101, USA.
Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE 68583, USA.
Transl Anim Sci. 2025 Jul 22;9:txaf099. doi: 10.1093/tas/txaf099. eCollection 2025.
A 3-yr study evaluated the effect of late gestation supplementation strategy on cow-calf performance, subsequent steer feedlot performance, and carcass characteristics. Mature March-calving crossbred cows (n = 357) were stratified by body weight (BW) and body condition score (BCS) and assigned to one of 4 treatments: 1) no supplementation (), 2) 0.91 kg/d of a 30% CP distillers-based supplement (DBS) (), 3) 0.91 kg/d of a 30% CP DBS with 160 mg/cow/d of monensin (; Rumensin 90, Elanco Animal Health), and 4) 0.91 kg/d of a 30% CP DBS with 40 g/cow/d propionate salt (, NutroCal 100, Kemin Industries). Cows were individually supplemented daily using a Super SmartFeed (C-Lock Inc., Rapid City, SD) from November to February. After weaning, steers (n = 181) were transported to the West Central Research and Extension Center and placed in a GrowSafe feeding system for finishing. Steers were slaughtered at a commercial facility (Tyson Fresh Meats, Lexington, NE) after fed to a common endpoint each year. Cow BW was not different ( = 0.87) at the initiation of the study in November. However, NoSupp cows were lighter ( < 0.01) at pre-calving and pre-breeding compared to supplemented cows. In contrast, NoSupp cows lost less ( < 0.01) BW from pre-calving to pre-breeding than supplemented cows and gained more ( = 0.01) BW from pre-breeding to weaning. Treatment tended to influence overall pregnancy rates ( = 0.09). Supp and CaProp dams had increased pregnancy rates over NoSupp and RUM ( ≤ 0.05). Offspring from NoSupp dams had lighter ( < 0.01) BW at birth, pre-breeding, and weaning than their counterparts from supplemented dams. In addition, steer feedlot entry, final BW, and hot carcass weight were greater ( < 0.01) when dams were supplemented compared to NoSupp. Steer feedlot average daily gain and gain:feed ratio was not influenced ( ≥ 0.31) by dam supplementation strategies; however, dry matter intake tended ( = 0.09) to be influenced by treatment. Percentage of carcasses grading Choice or greater was not influenced ( = 0.66) treatment; however, steers from dams fed CaProp had increased ( = 0.04) marbling scores. Protein supplementation during late gestation is an effective strategy to increase cow BW, maintain cow BCS, and increase progeny BW. Providing dams with propionate salts during late gestation positively improved marbling score of the subsequent steer carcass characteristics.
一项为期3年的研究评估了妊娠后期补饲策略对母牛-犊牛生产性能、后续架子牛育肥性能及胴体特性的影响。将体重（BW）和体况评分（BCS）分层的357头3月产犊的成年杂交母牛分配到4种处理之一：1）不补饲（），2）每天补饲0.91千克含30%粗蛋白的酒糟类补充料（DBS）（），3）每天补饲0.91千克含30%粗蛋白的DBS并添加160毫克/头/天的莫能菌素（；瘤胃素90，伊兰科动物保健公司），4）每天补饲0.91千克含30%粗蛋白的DBS并添加40克/头/天的丙酸盐（，营养钙100，凯明工业公司）。从11月至2月，使用超级智能饲喂器（C-Lock公司，南达科他州拉皮德城）对母牛进行每日单独补饲。断奶后，181头架子牛被运至中西部研究与推广中心，放入GrowSafe饲喂系统进行育肥。每年将架子牛饲养至共同终点后，在一家商业屠宰场（泰森鲜肉公司，内布拉斯加州列克星敦）屠宰。11月研究开始时，母牛的体重无差异（=0.87）。然而，与补饲母牛相比，未补饲母牛在产犊前和配种前体重较轻（<0.01）。相反，未补饲母牛从产犊前到配种前体重损失比补饲母牛少（<0.01），从配种前到断奶体重增加更多（=0.01）。处理方式对总体妊娠率有影响趋势（=0.09）。补饲组和丙酸钙组母牛的妊娠率高于未补饲组和瘤胃素组（≤0.05）。未补饲组母牛的后代在出生、配种前和断奶时的体重比补饲组母牛的后代轻（<0.01）。此外，与未补饲组相比，母牛补饲后架子牛进入育肥期的体重、最终体重和热胴体重更大（<0.01）。母牛补饲策略对架子牛育肥期平均日增重和增重：饲料比无影响（≥0.31）；然而，干物质采食量受处理方式影响有趋势（=0.09）。胴体评级为精选级或更高等级的比例不受处理方式影响（=0.66）；然而，饲喂丙酸钙的母牛所产架子牛的大理石花纹评分有所提高（=0.04）。妊娠后期补充蛋白质是增加母牛体重、维持母牛体况评分和增加后代体重的有效策略。妊娠后期给母牛提供丙酸盐可显著改善后续架子牛胴体的大理石花纹评分。
