Effects of offering lupins/triticale and vetch/barley silages alone or in combination with grass silage on animal performance, meat quality and the fatty acid composition of lean meat from beef cattle

An experiment was carried out to examine the effects of offering beef steers grass silage (GS) as the sole forage, lupins/triticale silage (LTS) as the sole forage, a mixture of LTS and GS at a ratio of 70:30 on a dry matter (DM) basis, vetch/barley silage (VBS) as the sole forage, a mixture of VBS and GS at a ratio of 70:30 on a DM basis, giving a total of five silage diets. Each of the five silage diets was supplemented with 2 and 5 kg of concentrates/head/day in a 5 x 2 factorial design to evaluate the five silages at two levels of concentrate intake and to examine possible interactions between silage type and concentrate intake. A total of 80 beef steers were used in the 122-day experiment. The GS was well preserved while the whole crop cereal/legume silages had high ammonia-nitrogen (N) concentrations, low lactic acid concentrations and low butyric acid concentrations For GS, LTS, LTS/GS, VBS and VBS/GS, respectively, silage DM intakes were 6.5, 7.0, 7.2, 6.1 and 6.6 (s.e.d. 0.55) kg/day and live weight gains were 0.94, 0.72, 0.63, 0.65 and 0.73 (s.e.d. 0.076) kg/day. Silage type did not affect carcass fatness, the colour or tenderness of meat or the fatty acid composition of the intramuscular fat in the longissimus dorsi muscle.