Effects of pasture fertiliser N level and winter diet type on performance, carcass and muscle traits of beef steers

Use of high levels of fertiliser N on pasture and silage making can cause environmental pollution through nitrate leaching to ground water and accidental seepage of silage effluent to water courses. The reformed Common Agricultural Policy of the European Union promotes more extensive beef production on grassland to reduce these risks. The objective of the present study was to ascertain the consequences for animal performance and carcass traits of reducing fertiliser N and eliminating silage making in beef production.Forty eight Charolais x Friesian yearling steers (initial liveweight 358 kg) were allocated to 4 treatments in a 2 × 2 factorial experiment at turn-out to pasture in April. The two factors were fertiliser N level (215 (Normal) and 57 (Low) kg/ha) over two consecutive grazing seasons and type of feed (grass silage or by-products) during the intervening winter.