Publication: Physiologic, health, and performance responses of beef steers supplemented with an immunomodulatory feed ingredient during feedlot receiving
Loading...
Date
Advisor
Coadvisor
Graduate program
Undergraduate course
Journal Title
Journal ISSN
Volume Title
Publisher
Type
Article
Access right
Acesso aberto
Abstract
One hundred eight Angus × Hereford steers, originating from 7 cow–calf were obtained from an auction yard on d −2 and transported by road (800 km; 12 h) to an experimental feedlot facility. Upon arrival on d −1, shrunk BW was recorded and steers were grouped with free-choice access to grass hay, mineral supplement, and water. On d 0, steers were ranked by source and shrunk BW and assigned to 1 of 18 pens (6 steers/pen). Pens were allocated to 1) no immunomodulatory ingredient supplementation during feedlot receiving (CON), 2) supplementation with OmniGen-AF (OMN; 22 g/steer daily, as-fed basis; Phibro Animal Health Corp., Teaneck, NJ) from d 0 to 30, or 3) 2 oral capsules of Stocker Immune Primer on d 0 + 15 g/ steer daily (as-fed basis) of Stocker Preconditioned Premix (Ramaekers Nutrition, Santa Cruz, CA) from d 7 to 30 (IPF). From d 0 to 80, steers had free-choice access to grass hay and water and received a corn-based concentrate. Feed DMI was recorded from each pen, and steers were assessed for bovine respiratory disease (BRD) signs daily. Steers were vaccinated against BRD pathogens on d 0 and 21. Final shrunk BW was recorded on d 81, and blood samples were collected on d 0, 3, 7, 10, 14, 21, 31, 42, 56, and 73. Steer ADG and final BW were greater (P ≤ 0.05) in CON steers than in OMN and IPF steers (1.23, 0.76, and 1.06 kg/d [SEM 0.06], respectively, and 320, 282, and 307 kg [SEM 4], respectively) and (P < 0.01) in IPF steers than in OMN steers. No treatment effects were detected (P ≥ 0.76) for BRD incidence (66 ± 4%) and DMI, whereas G:F was greater (P < 0.01) in OMN steers than in CON steers. Mean plasma cortisol concentration was greater (P = 0.01) in CON steers than in OMN and IPF steers. Plasma haptoglobin concentrations tended (P = 0.10) to be greater in CON steers than in IPF steers on d 3, were greater (P = 0.04) in IPF steers than in CON steers on d 7, and tended (P = 0.10) to be less in OMN steers than in IPF and CON steers on d 21. Blood mRNA expression of interleukin 8 was greater (P ≤ 0.05) in OMN and IPF steers than in CON steers on d 3 and in OMN steers than in CON and IPF steers on d 14. Blood mRNA expression of tumor necrosis-α was greater (P ≤ 0.05) in OMN and IPF steers than in CON steers on d 10. Plasma IGF-I concentrations, serum antibody titers to BRD pathogens, and blood mRNA expression of chemokine ligand 5, cyclooxygenase 2, interleukin 8 receptor, and L-selectin did not differ (P ≥ 0.21) among treatments. Collectively, the immunomodulatory feed ingredients evaluated herein impacted adrenocortical and innate immune responses but failed to mitigate BRD incidence and improve performance of receiving cattle.
Description
Keywords
Immunomodulatory ingredients, Innate immunity, Performance, Receiving cattle, Respiratory disease
Language
English
Citation
Journal of Animal Science, v. 95, n. 11, p. 4945-4957, 2017.
