Hall Jean A, Bobe Gerd, Vorachek William R, Klopfenstein Joseph J, Thompson Ian O, Zurita Cruz Cindy L, Dolan Brian P, Jin Ling, Davis T Zane
Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, Corvallis, OR, 97331, USA.
Department of Animal and Rangeland Sciences, College of Agricultural Sciences, Oregon State University, Corvallis, OR, 97331, USA.
Biol Trace Elem Res. 2024 Dec 20. doi: 10.1007/s12011-024-04457-1.
Supranutritional Se supplementation may improve immune responses in beef cattle. Immunity is compromised in beef cattle during the periparturient period. This study aims to determine the best time during pregnancy to supplement beef cows with Se-yeast to optimize humoral immunity at parturition. Multiparous, black Angus and Angus cross cows (n = 79) were used in the study. All cows had ad libitum access to a mineral supplement containing 120 mg/kg Se (US FDA regulations) from Na selenite. In addition, all cows except controls (CTR) received Se supplementation of 105 mg Se/week from Se-yeast boluses administered once weekly during their specific treatment trimester of gestation (TR1, TR2, or TR3) for 13 weeks. This dosage was supranutritional equaling 5 × the upper range of US FDA Se administration regulations. Blood was collected at parturition from all cows. Laboratory analyses studied to assess humoral immunity included measuring IBR, BVD types 1 and 2, PI3, and BRSV serum neutralization titers post vaccination, assessing total IgM and antigen-specific IgM concentrations, and determining complement-mediated bacterial killing percentages. Statistical analyses were performed using GraphPad Prism and SAS 9.4. Supranutritional Se-yeast supplementation increased whole-blood (WB) Se concentrations regardless of trimester of supplementation (all P < 0.0001). Supplementation during TR2 and TR3 was more effective in increasing WB-Se concentrations at parturition than during TR1 or CTR (all P < 0.0001). TR2 cows had higher serum neutralization titers for BRSV compared with CRT cows (P = 0.03). Total serum IgM and Vibrio coralliilyticus-specific IgM concentrations were highly correlated (r = 0.78; P < 0.0001). Compared with CTR cows, TR1, TR2, and TR3 cows had similar total IgM concentrations (all P ≥ 0.19) and similar Vibrio coralliilyticus-specific IgM concentrations (all P ≥ 0.47). Complement-mediated bacterial killing percentages were greater in TR2 and TR3 cows (> 99.6%) compared with TR1 (93.9%) and CTR (89.3%) cows, and all Se-supplemented TR groups were greater than CTR cows (all P ≤ 0.05). The significant group differences in the complement-mediated bacterial killing assay reflected WB-Se concentrations. Supranutritional Se-yeast supplementation during TR2 and TR3 is associated with higher serum neutralization titers for some viral antigens, as well as enhanced complement-mediated bacterial killing in cows at parturition. These findings suggest that Se supplementation during later trimesters of pregnancy may help combat infectious disease challenges during the periparturient period in beef cattle.
超营养水平的硒补充可能会改善肉牛的免疫反应。肉牛在围产期的免疫力会受到损害。本研究旨在确定在怀孕期间给肉牛补充硒酵母的最佳时间，以优化分娩时的体液免疫。本研究使用了经产的黑色安格斯牛和安格斯杂交牛（n = 79）。所有母牛均可自由采食含120毫克/千克硒（符合美国食品药品监督管理局规定）的亚硒酸钠矿物质补充剂。此外，除对照组（CTR）外，所有母牛在其特定的妊娠治疗期（TR1、TR2或TR3）每周接受一次硒酵母丸剂补充，剂量为105毫克硒/周，持续13周。该剂量为超营养水平，相当于美国食品药品监督管理局硒给药规定上限的5倍。在所有母牛分娩时采集血液。为评估体液免疫而进行的实验室分析包括测量接种疫苗后IBR、1型和2型牛病毒性腹泻、PI3和牛呼吸道合胞病毒血清中和滴度，评估总IgM和抗原特异性IgM浓度，以及测定补体介导的细菌杀伤百分比。使用GraphPad Prism和SAS 9.4进行统计分析。无论补充期处于哪个阶段，超营养水平的硒酵母补充均会提高全血（WB）硒浓度（所有P < 0.0001）。与TR1期或对照组相比，在TR2期和TR3期进行补充在提高分娩时的WB-硒浓度方面更有效（所有P < 0.0001）。与对照组母牛相比，TR2期母牛对牛呼吸道合胞病毒的血清中和滴度更高（P = 0.03）。血清总IgM和溶珊瑚弧菌特异性IgM浓度高度相关（r = 0.78；P < 0.0001）。与对照组母牛相比，TR1、TR2和TR3期母牛的总IgM浓度相似（所有P ≥ 0.19），溶珊瑚弧菌特异性IgM浓度也相似（所有P ≥ 0.47）。与TR1期（93.9%）和对照组（89.3%）母牛相比，TR2期和TR3期母牛的补体介导的细菌杀伤百分比更高（> 99.6%），并且所有补充硒的TR组均高于对照组母牛（所有P ≤ 0.05）。补体介导的细菌杀伤试验中的显著组间差异反映了WB-硒浓度。在TR2期和TR3期进行超营养水平的硒酵母补充与某些病毒抗原的血清中和滴度升高以及分娩时母牛补体介导的细菌杀伤增强有关。这些发现表明，在妊娠后期补充硒可能有助于应对肉牛围产期的传染病挑战。
