• Intake, growth and feed conversion efficiency of finishing beef cattle offered diets based on triticale, maize or grass silages, or ad libitum concentrates

      O'Kiely, Padraig (Teagasc (Agriculture and Food Development Authority), Ireland, 2011)
      The intake, growth and feed conversion efficiency of finishing cattle offered whole-crop triticale silage, harvested at different stubble heights, or maize silage, supplemented with different amounts and forms of crude protein, were compared with those of cattle offered grass silage or concentrate ad libitum. Ninety-eight continental crossbred steers (mean (s.d.) initial live weight 509 (38.6) kg) were allocated among 7 treatments in a randomized complete-block design: triticale silage from a crop harvested to a 14 (TS-L) or 35 (TS-H) cm high stubble, maize silage supplemented with a low (MS-LS) or high (MS-HS) protein concentrate, or with approximately half of the supplementary crude protein replaced by urea (MS-SU), grass silage (GS) or concentrate offered ad libitum (ALC). Each silage was offered ad libitum for 134 days, supplemented with 3 kg concentrate per head daily. Carcass gain did not differ (P>0.05) between animals on treatments TS-L and TS-H, but the carcass gain associated with TS-L was lower (P<0.05) than with GS or MS-HS, and with TS-H compared with MS-HS. Carcass gain was lower (P<0.05) for steers on GS compared to MS-HS, there were no differences (P>0.05) among the values for MS-LS, MS-HS and MS-SU; the carcass gain associated with ALC was the highest (P<0.001). The feed efficiency for carcass gain for the animals on TS-L, TS-H, GS, MS-LS, MS-HS, MS-SU and ALC was 44.1, 48.2, 60.8, 59.3, 68.3, 59.8 and 90.1 (s.e. 4.26) kg/t total DM intake, respectively (P<0.001). It is concluded that the ranking on nutritive value was TS<GS<MS<ALC. Elevating the cutting height of triticale conferred little benefit. Half the soybean meal in the barley-based supplement to maize silage could be replaced by barley plus urea without a negative effect on animal performance.