Date of Award
Master of Science
Henry G. Kattesh
John C. Waller, Emmit Rawls, Gina M. Pighetti
Two experiments examined growth performance and physiological measures of stress in pre- and postweaned Angus steers (313 ± 24.5 kg; n = 48/Exp.), where steers were fitted with (YD) or without (ND) an anti-suckling device (Exp. 1), or provided (YS) or not provided (NS) a grain supplement (Exp. 2) for 7 d and weaned by fenceline (FS) or total separation (TS). Steers in Exp. 1 were weighed and bled on d 0, 3, 7 10, 14, 21, and 42, and in Exp. 2, on d 0, 7, 10, 14, and 21 and provided a grain supplement on d 7-21. In Exp. 1, weight gain was not different (P = 0.74) between ND and YD steers during preweaning. The YD-FS steers lost weight (P = 0.01) by d 10 compared with YD-TS steers. Hematocrit (Hct) increased (P = 0.04) in YD but not ND steers on d 3. Neutrophil:lymphocyte ratio (N:L) increased (P < 0.01) in all steers by d 7. Cortisol values in YD-FS steers were higher (P < 0.05) compared with YD-TS steers on d 10 and 21. The ND-FS steers had higher (P = 0.04) interferon-gamma (IFN) concentrations on d 10 compared with all YD steers. Haptoglobin (HAP) values increased (P < 0.01) in all steers by d 3. The FS steers had higher (P < 0.01) ceruloplasmin (CER) values by d 10 than TS steers regardless of preweaning treatment. Ovalbumin-specific IgG increased (P < 0.01) in all steers 10 d following its administration. In Exp. 2, NS-TS steers lost weight (P < 0.01) between d 7 and 10 compared with the remaining steers. The YS steers had higher cortisol, N:L and CER on d 7 compared with NS steers. Moreover, NS steers had higher (P < 0.01) Hct on d 10 than YS steers. Based upon physiological and growth performance data, it may be concluded that use of an anti-suckling device prior to weaning does not improve the animals’ well-being and, providing a grain supplement beginning 7 d prior to weaning may temper the animals’ stress response due to weaning when total separation is employed.
Campistol, Cristina, "The Effects of Weaning Strategy on the Physiology and Performance of Beef Calves. " Master's Thesis, University of Tennessee, 2010.