|KATTESH, HENRY - University Of Tennessee|
|CAMPISTOL, CRISTINA - University Of Tennessee|
|WALLER, JOHN - University Of Tennessee|
|RAWLS, EMMIT - University Of Florida|
|ARTHINGTON, JOHN - University Of Florida|
|Carroll, Jeffery - Jeff Carroll|
|PIGHETTI, GINA - University Of Tennessee|
|SAXTON, ARNOLD - University Of Tennessee|
Submitted to: International Journal of Livestock Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/31/2016
Publication Date: 8/20/2016
Citation: Kattesh, H.G., Campistol, C., Waller, J.C., Rawls, E.L., Arthington, J.D., Carroll, J.A., Pighetti, G.M., Saxton, A.M. 2016. Effects of pre-weaning feed supplementation and total versus fenceline weaning on the physiology and performance of beef steers. Professional Animal Scientist. 7(8):48-54.
Interpretive Summary: The traditional method of weaning beef cattle involves abrupt separation of calves from their dams. Upon weaning, calves are either relocated to an adjoining pasture for a brief period (fenceline contact), which prevents them from nursing but allows some social contact with their dams, or moved to a distant pasture practically eliminating all forms of social interaction between a cow and their offspring. Calves weaned by the abrupt method and moved to a distant pasture exhibit greater signs of distress, as evidenced by increased movement and vocalization and decreased food consumption, compared to calves provided temporary fenceline contact. As an alternative to the traditional method, weaning strategies incorporating a pre-conditioning program have been investigated with the overall objective of reducing the stress associated with breaking the cow-calf bond. To evaluate alternative weaning strategies that could be used to reduce stress in beef calves, scientists from the Livestock Issues Research Unit collaborated on a study with scientists from the University of Tennessee and the University of Florida to document the effects of two different weaning strategies on the physiology and growth performance of beef steers. Results from this study indicated that regardless of weaning strategy, all calves exhibited changes in the growth and physiological indices measured in this study consistent with that associated with weaning stress. However, the extent of change appeared moderated in animals given prior access to a pre-weaning diet, especially for those subjected to total separation. This information will be of special interest to beef cattle producers and to scientists in academia, industry and government agencies working in the field of beef cattle production focused on reducing the effects of weaning stress on subsequent health and performance of beef calves.
Technical Abstract: Forty-eight Angus steer calves (initial body weight = 312 ± 28 kilograms), housed on pasture with their dams, were equalized by initial body weight and assigned randomly to receive a highly palatable, high fiber supplement (YS; 4.5 kilograms/head/day) or no supplement (NS) for 7 days prior to weaning. Calves (12 NS and 12 YS) were weaned (day 0) by fenceline (FS) or total separation (TS). On day 7 the FS group was moved to a pasture lot distant from their dams and adjoining the TS group. All steers were weighed and bled on days -7, 0, 3, 7, 14, and 35 (body weight only) and provided access to the fiber supplement on days 0 to 14. By day 0, body weight gain increased (P < 0.01) and serum interferon- gamma (IFN) concentration decreased (P < 0.01) in all steers. However, the YS steers exhibited greater (P < 0.05) neutrophil to lymphocyte (N:L) ratio and plasma cortisol (CORT; P = 0.09) and ceruloplasmin (CER; P = 0.08) concentrations compared with NS steers. From weaning to day 7, NS-TS steers initially experienced a weight loss (P < 0.01) followed by a compensatory body weight gain (P < 0.01) when compared with the remaining steers. At 3 days postweaning, mean hematocrit for YS steers was lower (P < 0.01) than that of NS steers and CORT was greater (P < 0.05) for NS-TS versus YS-TS steers. Red blood cell number, N:L ratio, haptoglobin and IFN concentrations increased (P < 0.01) in all steers by day 3 and returned to pre-weaning concentrations thereafter. From day 14 to 35, NS-FS steers gained less (P < 0.01) weight compared with YS-FS and all TS steers. These results suggest that providing a high fiber supplement beginning 7 days prior to weaning using total separation may reduce body weight loss and temper the calves' acute stress response due to weaning.