Effects of a bovine maternal appeasing substance at weaning on behavior, preconditioning performance, health, and economic return of beef calves

The objective of these experiments was to determine whether administration of a bovine appeasing substance (BAS) at weaning altered calf behavior, preconditioning performance, bovine respiratory disease (BRD), and estimated economic return. A total of 544 calves from three commercial cow-calf herds in Minnesota and South Dakota were assigned within experiment to BAS or a mineral oil control (CON) at weaning and evaluated during a 42-d preconditioning period. Behavior was assessed by instantaneous scan sampling during the first 48 h. Body weight (BW), average daily gain (ADG), BRD morbidity, and mortality were measured in all experiments; dry matter intake (DMI) and gain-to-feed ratio (G:F) were measured in experiments 1 and 2. Behavioral treatment × experiment interactions were detected (P < 0.001). BAS calves had greater feeding, lying, and drinking proportions in all experiments (P < 0.001) and walked less in experiments 1 and 2 (P < 0.001), whereas walking did not differ in experiment 3 (P = 0.232). Initial BW did not differ between treatments (P ≥ 0.865). Final BW and ADG were greater for BAS in experiments 1, 2, and 3 (P ≤ 0.044). BAS reduced DMI and increased G:F in experiments 1 and 2 (P < 0.001). BRD morbidity was lower for BAS in all experiments (P < 0.001). Mortality was lower for BAS in experiment 1 (P < 0.001), did not differ in experiment 2 (P = 0.999), and was zero for both treatments in experiment 3. Estimated profit favored BAS in each experiment, although economic outcomes depended on the prices and assumptions used. Collectively, BAS administration at weaning altered behavior in a manner consistent with improved adaptation and was associated with greater growth, improved feed efficiency, reduced BRD morbidity, and favorable estimated returns. Additional studies with greater pen replication are warranted to define response consistency across management systems.