Impact of a slow walk at pre-slaughter on behavior, physiology, oxidative stress, carcass and meat quality in beef cattle.

Stress is inevitable in pre-slaughter management. Unusual physical activity is a stress factor since cattle are sedentary animals. We investigated the effect of a slow walk, the day before slaughter, on steers' physiology, behavior, energy and antioxidant reserves, carcass and meat quality. Over five years, 660 pasture-finished steers were evaluated. In each slaughter, animals were individually weighed and randomly allocated to one experimental group (n= 15/group): 0 (unexercised control) and 10km (walking stress). Twenty-two slaughters were considered in a randomized complete block design. Steers walked 10km at an average speed of 4.22km/h in approximately 2h 22min. On farm, in the hour following the end of the exercise, the "walking stress" steers reduced rumination sixfold (P = 0.002) and increased panting tenfold (P = 0.003) than steers from unexercised control. Water intake was double in the "walking stress" group compared to unexercised steers (P = 0.005). After slaughter, no differences (P > 0.10) were found on carcass traits, blood indicators of stress, and muscle antioxidants. Steers of the "walking stress" showed lower drip (P = 0.07) and cooking (P = 0.08) losses and shear force (P = 0.04) than those from the unexercised control group. Glycogen concentration was lower (P = 0.006) in steers from "walking stress" group than in unexercised control, without differences (P > 0.10) in lactate. A walk on the day before slaughter, at the speed and distance employed, generated physiological and behavioral responses, but did not compromise carcass and meat quality traits.