Effect of regular walking exercise on glucose tolerance and insulin response to i.v. glucose infusion in growing beef steers

Abstract

The purpose of the present paper was to investigate the effect of regular walking exercise on glucose tolerance and insulin response to i.v. glucose infusion in growing beef steers. Four crossbred beef steers walked on a treadmill during a 6 week exercise period (1.2 km/h, 1 h/day and 5 days/week). The changes in plasma glucose and insulin levels following glucose infusion were analyzed immediately prior to (bodyweight: 260.4 ± 24.2 kg) and after (295.7 ± 30.1 kg) the exercise period. The basal levels of plasma glucose (86.4 vs. 82.0 mg/dL, P = 0.040) and insulin (24.5 vs. 14.3 μU/mL, P = 0.016) were significantly lower after the exercise period. Further, the increase in the levels of plasma glucose (420.4 vs. 280.8 mg/dL, P < 0.001) and insulin (94.5 vs. 73.1 μU/mL, P = 0.028) following the glucose infusion decreased after the exercise period. The area under the curve of plasma glucose (108.8 vs. 62.9 mg/dL per min, P < 0.001) and insulin (53.6 vs. 29.7 μU/mL per min, P = 0.018) indicated more rapid clearance of exogenous glucose and less insulin secretion for glucose clearance after the exercise period. These results suggest that regular exercise improves glucose tolerance, with lower insulin response to glucose infusion in growing steers, as observed in rodents and humans.

Effects of Grazing or Exercise in the Middle of the Fattening Period on the Growth and Carcass Traits of Japanese Shorthorn Steers

“…The purpose of the study is to investigate the effects of grazing or exercise in the middle of the fattening period on growth and carcass traits. The treadmill is a major tool used in studies concerning the effect of exercise on muscle biology (Aalhus et al 1991, Apple et al 1994, Aoki et al 2007). As we were unable to use a treadmill, however, we selected an alternative method of making cattle walk a training course as exercise.…”