Each year from 1975 to 1977, three groups of six beef steers, 9 months old, were stocked at 2.6 ha-l and managed under one of the following treatments: (1 ) Pasture only (PO), no supplementary feeding, (2) Winter feeding (WF) ; pasture hay was cut from 33% of the grazed area, stored and fed back the following winter while the steers were at pasture. (3) Autumn deferment (AD) ; 33% of the grazed area was cut for hay and rolled using an Econ fodder roller. For 8-11 weeks after the opening rains, the steers were fed a complete hay ration of fodder rolls while confined to a tenth of the grazed area. Thereafter the steers grazed the whole area. The AD and WF hay averaged 11% crude protein, and 56% digestible organic matter. The growth rate of all groups during autumn was similar and averaged 0.1 5 kg day-1. During winter, the average growth rates of the PO, WF and AD groups were 0.26, 0.44 and 0.61 kg day-1, respectively. In spring the respective growth rates were 1.09, 0.81 and 0.77 kg day1 and the overall growth rates were 0.40, 0.37 and 0.42 kg day-1. The results show that when using average quality hay produced within the grazing system, AD is more effective than WF in increasing the winter liveweight gains of steers. However, the yearly beef production from each system was similar due mainly to compensatory growth by the PO steers in spring.
Effect of Feeding a Low Vitamin a Diet to Beef Steers on Calpain 1 Activation during Meat Aging
