118 Administering a synthetic appeasing pheromone to Bos indicus-influenced beef cattle at weaning and feedlot entry

Abstract

Abstract Synthetic appeasing pheromone (SAP) is expected to have a calming effect in cattle experiencing stressful situations, including weaning and feedlot arrival. In Exp. 1, 186 Bos indicus-influenced calves (73 heifers, 133 bulls) were weaned at 211 ± 1 d of age (d 0). Upon weaning, calves were ranked by sex and body weight (BW), and assigned to receive SAP (Nutricorp, Araras, SP, Brazil; n = 94) or water (CON; n = 92). Treatments (5 mL) were topically applied to the forehead of each animal. Calf BW was recorded on d 15 and 45. Calves that received SAP had greater (P < 0.01) average daily again (ADG) from d 0 to 15, and BW on d 15 compared with CON (0.94 vs. 0.73 kg/d and 249 vs. 246 kg; respectively). Calf ADG from d 15 to 45 was similar (P = 0.97) between treatments. Overall ADG and BW on d 45 were also greater in SAP vs. CON (0.36 vs. 0.29 kg/d and 251 vs. 248 kg; respectively). In Exp. 2, 140 Bos indicus-influenced bulls (~27 mo of age) were transported from a cow-calf ranch to a commercial feedlot (d -1), and maintained on a single pasture for 24 h. On d 0, bulls were ranked by BW and assigned to receive SAP (n = 70) or CON (n = 70) as in Exp. 1. Bulls receiving SAP had greater (P = 0.04) ADG from d 0 to 15, but less (P <0.01) ADG from d 15 to 45 compared to CON (1.65 vs. 1.45 kg/d and 1.42 vs. 1.65 kg/d; respectively). No other treatment effects were detected (P ≥ 0.18). Therefore, SAP administration to beef cattle at weaning or feedlot entry had immediate benefits to ADG, which were sustained for 45 d in weaned calves but not in feedlot cattle