This study evaluated the effects of maternal supplementation of Bacillus-based direct-fed microbials (DFM) on physiology and growth performance of Bos indicus-influenced cow-calf pairs. On d 0 (~139 d before expected calving date), 72 fall-calving, Brangus crossbred beef heifers (25 to 37.5% Bos indicus; 20 to 22 mo of age) pregnant with their first offspring were stratified by their initial body weight (BW; 431 ± 31 kg) and body condition score (BCS; 6.0 ± 0.36; scale 1 to 9), and randomly allocated into 1 of 12 bahiagrass pastures (1 ha and 6 heifers per pasture). Treatments were randomly assigned to pastures (6 pastures per treatment) and consisted of heifers supplemented with 1 kg/d of soybean hulls dry matter (DM) added (BAC) or not (CON) with a Bacillus-based DFM mixture (BovacillusTM; Chr. Hansen A/S, Hørsholm, Denmark) from d 0 to 242 (139 ± 4 d prepartum to 104 ± 4 d postpartum). Calves were weaned on d 242 (96 ± 30 d of age) and then allocated into 1 of 16 drylot pens and limit-fed the same concentrate at 3.25% of BW until d 319. Maternal treatment effects were not detected (P ≥ 0.29) for herbage allowance, forage nutritive value, and heifer activity on pasture. Heifer BCS on d 39 and 63 tended (P ≤ 0.09) to be greater, whereas heifer BCS on d 91 was greater (P = 0.01) for BAC vs. CON heifers and did not differ (P ≥ 0.20) between treatments on d 179 and 242. Plasma concentrations of glucose did not differ from d 0 to 63 (P ≥ 0.14) but were greater (P = 0.005) on d 179 and tended (P = 0.09) to be greater on d 242 for BAC vs. CON heifers. First offspring BW at birth, ADG from birth to early weaning, and BW weaning did not differ (P ≥ 0.19), but BW at drylot exit (d 319) was greater (P = 0.05) for BAC vs. CON calves. Maternal treatment effects were not detected (P ≥ 0.42) for calf serum concentrations of IgG at birth, and post-vaccination plasma concentrations of glucose, cortisol and haptoglobin. However, serum titers against bovine respiratory syncytial virus (BRSV) were greater (P = 0.04) for BAC vs. CON calves on d 287, whereas seroconversion against parainfluenza 3 virus (PI-3) was greater (P < 0.01) for BAC vs. CON calves on d 271. Thus, maternal supplementation of Bacillus-based DFM increased prepartum BCS gain and postpartum plasma concentrations of glucose of heifers and led to positive carryover effects on post-weaning BW gain and some indicators of humoral immune response to vaccination in their first offspring.

中文翻译：

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104 母亲产前和产后补充基于芽孢杆菌的 DFM 可提高奶牛和犊牛的生产性能

本研究评估了母体补充基于芽孢杆菌的直接饲喂微生物 (DFM) 对受 Bos indicus 影响的母牛和小牛对的生理和生长性能的影响。在第 0 天（预计产犊日期前约 139 天），72 只秋季产犊的 Brangus 杂交小母牛（25% 至 37.5% Bos indicus；20 至 22 月龄）怀有第一个后代，按其初始体重进行分层（体重；431 ± 31 kg）和身体状况评分（BCS；6.0 ± 0.36；量表 1 至 9），并随机分配到 12 个 bahiagrass 牧场中的 1 个（每个牧场 1 公顷和 6 头小母牛）。处理被随机分配到牧场（每个处理 6 个牧场），并由小母牛组成，其中小母牛补充了 1 kg/天的大豆皮干物质 (DM)，添加 (BAC) 或不添加 (CON) 以及基于芽孢杆菌的 DFM 混合物（BovacillusTM；Chr） .Hansen A/S，Hørsholm，丹麦）从 0 天到 242 天（产前 139 ± 4 天到产后 104 ± 4 天）。犊牛在第 242 天（96 ± 30 天龄）断奶，然后分配到 16 个干燥栏中的 1 个，并以体重的 3.25% 限制饲喂相同的浓缩物，直到第 319 天。未检测到母体治疗效果（P ≥ 0.29）牧草津贴、草料营养价值和牧场上小母牛的活动。对于 BAC 与 CON 的小母牛，第 39 和 63 天的小母牛 BCS 往往更大 (P ≤ 0.09)，而第 91 天的小母牛 BCS 更大 (P = 0.01)，并且在第 179 天的处理之间没有差异 (P ≥ 0.20)和 242. BAC 与 CON 母牛的血浆葡萄糖浓度从第 0 天到第 63 天没有差异（P ≥ 0.14），但在第 179 天更高（P = 0.005），并且在第 242 天倾向于（P = 0.09）更高。 。第一代后代出生时的体重、从出生到早期断奶的平均日增重以及断奶时的体重没有差异 (P ≥ 0.19)，但 BAC 犊牛与 CON 犊牛相比，在干燥场出口 (d 319) 时的体重更大 (P = 0.05)。对于出生时小牛血清 IgG 浓度以及疫苗接种后血浆葡萄糖、皮质醇和触珠蛋白浓度，未检测到母体治疗效果 (P ≥ 0.42)。然而，第 287 天，BAC 与 CON 犊牛相比，针对牛呼吸道合胞病毒 (BRSV) 的血清滴度更高 (P = 0.04)，而针对副流感 3 病毒 (PI-3) 的血清转化，BAC 更高 (P < 0.01)与第 271 天的 CON 犊牛相比。因此，母体补充基于芽孢杆菌的 DFM 增加了小母牛的产前 BCS 增益和产后血浆葡萄糖浓度，并对断奶后体重增益和疫苗接种的体液免疫反应的一些指标产生了积极的遗留影响在他们的第一个后代中。