Getting cattle to grow faster on lush autumn pastures

Abstract

Average daily gain (ADG), grazing behaviour and feed intake of Hereford steers grazing high autumn quality pastures were measured at two different levels of forage allowance (2.5 and 5.0 kg of dry matter/100 kg of body weight), with no supplement or with whole (WM) or ground (GM) maize grain fed at 1% of body weight. Thirty-six Hereford steers were assigned to one of six treatments in a factorial arrangement. Forage allowance was adjusted weekly for each treatment by varying paddock area. Grain was offered daily and refusals weighed to determine actual intake of each animal. Forage intake was estimated as the difference between forage availability before and after grazing. Grazing behaviour was determined by visual appraisal every 10 minutes during 9 hours of daylight for four consecutives days every second week. The ADG was higher (P<0.01) in supplemented cattle (1.12 kg/d) than non-supplemented (0.41 kg/d) controls. Forage allowance did not have a significant effect on ADG (P=0.07). There was an interaction (P=0.11) between forage allowance and supplementation on forage intake. At low forage allowance, forage intake was decreased (P<0.05), only if maize grain was offered ground. Supplementation did not affect grazing time. Steers grazing with a high forage allowance and supplemented with WM spent more time ruminating than those fed with GM.