Rients Emma L, Franco Carlos E, Hansen Stephanie L, McGill Jodi L
Department of Animal Science, Iowa State University, Ames, IA, USA.
Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, USA.
Transl Anim Sci. 2025 Aug 25;9:txaf115. doi: 10.1093/tas/txaf115. eCollection 2025.
During disease, there may be increased local demands for zinc (Zn) and vitamin A to support pathogen response. This study evaluates the effects of intranasal Zn and vitamin A treatments on steers experimentally infected with bovine respiratory disease (BRD) pathogens, bovine respiratory syncytial virus (BRSV) and , hypothesizing that steers treated with Zn and vitamin A (VA) will have improved recovery to BRD challenge. Forty-eight Angus crossbred steers (333 ± 4.2 kg) were utilized in two groups with identical challenge timelines. The day prior to challenge (d -1), steers were shipped for 6 hours. On d 0, steers were administered an aerosol inoculation with ~10 TCID/mL BRSV strain 375 followed by an intratracheal inoculation with (1.42 × 10 CFU strain D153, serotype A1) on d 5. On d 4, steers received intranasal treatments: zinc (IN ZN; 50 mg Zn oxide nanoparticles), vitamin A (IN VA; 200,000 IU as retinyl palmitate), a combination of zinc (50 mg) and vitamin A (200,000 IU; IN VA + ZN) or no treatment (CON). Statistics were analyzed using the Mixed procedure of SAS 9.4 (Cary, NC) and contrast statements were utilized to determine the effects of Zn, VA and intranasal treatment. Disease challenge resulted in mostly mild, subclinical signs of disease. There was an interaction for plasma VA (TRT × Day < 0.01) where VA treated steers (IN VA and IN VA + ZN) had sustained plasma VA concentrations on d 5, when ZN and CON had decreased plasma VA. After challenge (d 19), liver VA concentrations were increased in IN VA (IN VA = 0.03) and IN ZN (IN ZN = 0.05) treated steers. Zn treated steers (ZN and ZN + VA) tended to have increased gene expression of ( = 0.06) on d 5 and ( = 0.08) on d 7 in cells collected from nasopharyngeal swabs. Additionally, immune cell populations from bronchoalveolar lavage were altered with increased CD11b expression on neutrophils (IN VA = 0.01) and CD11c on macrophages (IN ZN = 0.08) on d 7. During a mild disease challenge, intranasal Zn and VA treatments impacted lung inflammatory environment and nutritional immunity, suggesting potential benefits in mild or deficient nutritional statuses.
在疾病期间，局部对锌（Zn）和维生素A的需求可能会增加，以支持病原体反应。本研究评估了鼻内注射锌和维生素A对实验感染牛呼吸道疾病（BRD）病原体牛呼吸道合胞病毒（BRSV）和的阉牛的影响，假设用锌和维生素A（VA）治疗的阉牛对BRD攻击的恢复情况会有所改善。48头安格斯杂交阉牛（333±4.2千克）被分为两组，具有相同的攻毒时间线。在攻毒前一天（第-1天），阉牛被运输6小时。在第0天，给阉牛进行气溶胶接种约10 TCID/mL的BRSV毒株375，随后在第5天进行气管内接种（1.42×10 CFU毒株D153，血清型A1）。在第4天，阉牛接受鼻内治疗：锌（鼻内锌；50毫克氧化锌纳米颗粒）、维生素A（鼻内维生素A；200,000国际单位视黄醇棕榈酸酯）、锌（50毫克）和维生素A（200,000国际单位；鼻内维生素A+锌）的组合或不治疗（对照组）。使用SAS 9.4（北卡罗来纳州卡里）的混合程序进行统计分析，并利用对比语句来确定锌、维生素A和鼻内治疗的效果。疾病攻击导致大多为轻度的亚临床疾病迹象。血浆维生素A存在交互作用（处理×天数<0.01），即接受维生素A治疗的阉牛（鼻内维生素A和鼻内维生素A+锌）在第天血浆维生素A浓度持续存在，而锌组和对照组的血浆维生素A浓度下降。攻毒后（第19天），接受鼻内维生素A（鼻内维生素A=0.03）和鼻内锌（鼻内锌=0.05）治疗的阉牛肝脏维生素A浓度升高。在第5天，锌治疗的阉牛（锌组和锌+维生素A组）鼻咽拭子采集的细胞中基因表达倾向于增加（=0.06），在第7天增加（=0.08）。此外，支气管肺泡灌洗的免疫细胞群体发生改变，在第7天中性粒细胞上的CD11b表达增加（鼻内维生素A=0.01），巨噬细胞上的CD11c表达增加（鼻内锌=0.08）。在轻度疾病攻击期间，鼻内锌和维生素A治疗影响了肺部炎症环境和营养免疫，表明在轻度或营养缺乏状态下可能有益。
