PSIV-4 Effectiveness of maternal bovine appeasing substance on growth, physiological, and behavioral responses of high-risk stocker cattle

Abstract Stocker cattle purchased at auction can be susceptible to disease due to the stressors associated with the auction process. These cattle are labeled “high-risk” due to their decreased immune system during transportation, handling, and vaccination processes. The objective of this study was to determine the efficacy of a maternal bovine appeasing substance, FerAppease, on growth performance and fearfulness of stocker cattle. Male beef calves (n = 80) were purchased at auction and transported to the University of Arkansas Division of Agriculture Savoy Research Complex Beef Stocker Unit. Steers and bulls were of varying age, breed, and temperament. Upon arrival to the facility (d 0), bulls (n = 48) were castrated by banding and cattle were assigned to 8 pens (n = 10 calves/pen; 4 bulls and 6 steers/pen). On d 0, cattle in 4 pens were treated with FerAppease (FA) on the nuchal skin (n = 40) and cattle in the other 4 pens were not treated and served as controls (CON, n = 40). All cattle received commercial clostridial and respiratory vaccines and were treated with an anthelmintic. Cattle were offered bermudagrass hay for ad libitum intake and were fed a grain supplement (1.8 kg/d) to meet or exceed nutrient requirements. To measure growth performance, body weight (BW) was recorded on d 0, 3, 14, 28, 41, 42 of the study and used to calculate average daily gain (ADG). Body weights on d 41 and 42 were averaged to calculate final BW. To measure fearfulness, exit chute velocity (ECV) was measured with a rodeo timer and recorded on d 3, 14, 28, 41, and 42. To measure inflammation, blood was collected from 5 calves/pen (n = 3 bulls and 2 steers/pen) on d 0, 3, 28 and 42 and haptoglobin (Hp) was measured in blood serum. A two-way ANOVA with the fixed effects of sex (arrived as steer or bull) and treatment (FA, CON) and random effect of pen was used for analysis. Serum Hp was log transformed to improve normality. There was not a treatment effect on any of the measures collected. Steers had a greater BW throughout the study (P ≤ 0.05), weighing more than bulls at the end of the study (261 kg vs 241 kg, respectively). Steers also had a greater (P < 0.0001) ADG than bulls (1.14 vs. 0.84 kg/d, respectively). On d 3 and 14, steers exited the chute more rapidly (P < 0.05) than bulls. There was an interactive effect on serum d 28 Hp concentrations (P = 0.04), where CON bulls had greater Hp concentrations (111,261 ng/mL) than CON steers (13,055 ng/mL), with FA steers and bulls intermediate. The results from this study indicate that there was no consistent effect of the treatment on the measures collected.