Immune Responses and Performance Are Influenced by Respiratory Vaccine Antigen Type and Stress in Beef Calves

• Main Authors: Rachel E. Hudson, Dexter J. Tomczak, Emily L. Kaufman, Ashlee M. Adams, Jeffery A. Carroll, Paul R. Broadway, Michael A. Ballou, John T. Richeson
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Animals
• Subjects: antibody; beef calves; physiological stress; vaccination
• Online Access: https://www.mdpi.com/2076-2615/10/7/1119

The study objective was to determine if a combined weaning and transportation stress model affected performance, antibody, endocrine, or hematological responses to modified-live virus (MLV) or killed virus (KV) respiratory vaccination in beef steers. In total, 48 calves (Day 0 BW = 226 ± 6.2 kg) from a single origin were used in a 2 × 2 factorial to evaluate main effects of stress model, vaccine type, and their interaction, resulting in four treatments (<i>n</i> = 12/treatment) including non-stress control (C) with KV (CKV), C with MLV (CMLV), stress model implementation (S) with KV (SKV), and S with MLV (SMLV). The C calves were weaned at the origin ranch on Day −37 and transported 472 km to the study site on Day −21 to allow acclimation. The S calves were weaned on Day −3, transported 460 km to a research facility on Day −2, held overnight, and transported 164 km to the study site on Day −1 to mimic the beef cattle marketing process. Vaccines were administered on Day 0 and KV was revaccinated on Day 14. The animal was the experimental unit and dependent variables were analyzed using PROC MIXED with repeated measures (day). A stress model effect (<i>p</i> = 0.01) existed for DMI from Day 0 to Day 7 with greater DMI for C (6.19 vs. 4.64 kg/day) when compared to S. The MLV groups had reduced (<i>p</i> = 0.05) ADG from Day 0 to Day 56, compared to KV. There was a vaccine type × day (<i>p</i> < 0.01) interaction with increased (<i>p</i> ≤ 0.01) PI3V- and IBRV-specific antibody titers for KV on Day 21; conversely, MLV had increased (<i>p</i> ≤ 0.01) BVDV titers on Days 14, 28, 35, 42, 49, and 56. Increased (<i>p</i> ≤ 0.05) BRSV titers were observed in a stress model × day (<i>p</i> < 0.01) interaction for S on Days 21, 28, 36, and 42; however, C exceeded S in BVDV-specific antibody concentration on Days 21, 28, and 49. A day effect (<i>p</i> < 0.01) was observed for serum haptoglobin with the greatest (<i>p</i> < 0.01) concentration on Day 3. Serum cortisol concentration was greater (<i>p</i> ≤ 0.04) for C vs. S on Days −2, 0, 1, 3, and 5. Total leukocytes were decreased for C vs. S on Days 0, 1, 3, 5, 7, 14, and 21 (<i>p</i> ≤ 0.02). A reduction (<i>p</i> ≤ 0.04) in total leukocytes was observed for MLV on Days 5, 7, and 14 vs. KV. Neutrophils and neutrophil:lymphocyte were markedly increased (<i>p</i> ≤ 0.01) for S on Day −2, whereas neutrophils were decreased (<i>p</i> ≤ 0.01) on Days 1 and 21 for S. Monocytes were decreased on Days 1, 5 and 7 for MLV (<i>p</i> ≤ 0.04) and Days −2 to 14 for S (<i>p</i> ≤ 0.03). Eosinophils were reduced (<i>p</i> = 0.007) for S vs. C on Day −2, yet a distinct rebound response (<i>p</i> = 0.03) was noted for S on Day 0. The results indicate that S and MLV vaccination more profoundly induced immunomodulation in beef calves.