Appeasing Substance Administration at Feedlot Entry Impacted Temperament, Pen Behavior, Immunocompetence, and Meat Quality of Beef Heifers.

This experiment evaluated the effects of bovine appeasing substance (BAS) administration at feedlot entry on growth, temperament, inflammation, response to vaccination, behavior, carcass characteristics, and meat quality of beef heifers. Thirty heifers were weaned and assigned to (d 0): (1) BAS (n = 15; SecureCattle; IRSEA Group) or (2) Saline (n = 15). On d 0, heifers were also vaccinated against respiratory diseases and slaughtered on d 150. Administering BAS increased (p = 0.05) average daily gain from d 6 to 45, reduced (p ≤ 0.03) plasma ceruloplasmin and serum cortisol concentrations on d 15 and 45 and increased (p = 0.03) the response to vaccination. Additionally, BAS reduced (p < 0.01) the entry scores on d 6, 15, and 45 and reduced (p = 0.05) exit scores on d 2, 6, and 15. The BAS increased (p ≤ 0.04) walking, drinking, and eating time, and tended (p ≤ 0.10) to increase lying and ruminating time. Lastly, BAS tended (p ≤ 0.10) to increase the myofibrillar fragmentation index and reduce the thiobarbituric acid reactive substance concentration in meat. Thus, BAS administration increased growth, reduced stress, and inflammation, and improved immune responses, behavior, and meat quality of heifers.