Concentrate Supplements for Weanling and Finishing Steers

Abstract

Concentrates are a major cost element in feeding beef cattle in winter. Because of the need to retain finishing cattle until after specific dates to comply with retention periods for the draw-down of premia, feeding strategies must be flexible. The objectives of this study were to examine concentrate feeding strategies which would minimise concentrate feeding to weanlings and exploit compensatory growth, simplify feeding routines and improve the efficiency of concentrate utilisation in finishing cattle. Four experiments were carried out, two with weanlings and two with finishing cattle. • Weanlings fed outdoors (in sacrifice paddocks) in winter gained 13 kg more than those similarly fed indoors but by the end of the following grazing season the weight difference had decreased to 4 kg as a result of compensatory growth. • There was no response to an increase in protein level in the concentrate. • Feeding 2 kg/day of supplementary concentrates with silage in winter reduced silage intake by 0.4 kg dry matter (DM) and increased total DM intake by 1.27 kg/day. • The liveweight gain response in winter to 2 kg/day supplementary concentrates was 344 g/day or a total of 44 kg. By the end of the following grazing season this had declined to 14 kg (68% compensation) • The conversion ratio of concentrate DM to liveweight was about 5:1 at the end of winter but by the end of the following grazing season it was over 15 : 1. • Feeding a fixed total concentrate allowance to weanlings gave a better response when it was offered at a flat rate daily over the whole winter, or at a high rate over the first half of the winter, rather than when offered at a high rate over the second half of the winter. • Feeding a fixed total concentrate allowance ad libitum over the final part of the finishing period was superior to feeding it at a flat rate per day over the total period in terms of feed energy utilization. • There was no impairment in the efficiency of total feed energy utilization by delaying the feeding of a fixed concentrate allowance for up to 70 days after housing compared to feeding it immediately after housing. • Where animals are being finished over a 5-6 months period, rather than feeding concentrates at a flat rate throughout the whole period, it is better to delay introduction for 2-3 months and then offer concentrates ad libitum thereafter. • As the interval from housing to concentrate introduction increases, the response to concentrates fed ad libitum subsequently increases. • Although not reflected in carcass fat score, objective indicators of fatness were lower for animals fed concentrates ad libitum than for animals fed concentrates at a flat rate with silage.