Influence of biochar supplementation on comparative growth performance and carcass characteristics of Angus × Holstein vs. Charolais × Holstein calf-fed steers.

The objective of the current study was to determine the influence of biochar supplementation on steer growth performance, carcass characteristics, and ruminal temperature of calf-fed Angus × Holstein (AXH) crossbred steers versus calf-fed Charolais × Holstein (CXH) crossbred steers fed for over 300 d. Fifty-six AXH crossbred steers (body weight (BW) = 192 ± 12 kg), and 56 CHX steers (BW = 188 ± 13 kg) were blocked by initial BW and assigned randomly to 28 pens. Dietary treatments consisted of a steam-flaked corn-based diet supplemented with 1) no biochar supplementation (control); 2) 0.2% (dry matter (DM) basis) of Biochar. Data were analyzed as a randomized complete block in a 2 × 2 factorial arrangement, using pens as the experimental unit. From 112 to 224 d on feed, dietary supplemental biochar decreased (P = 0.05) cattle average daily gain (ADG). However, there were no other dietary effects (P ≥ 0.11) on steer growth performance or performance-adjusted net energy values. Biochar supplementation tended (P ≥ 0.08) to decrease the marbling score and increase calf morbidity. Biochar had no other effects (P > 0.13) on carcass characteristics. Angus cross steers had a greater (P ≤ 0.05) final live weight and DM intake compared to CXH steers. Moreover, AXH steers tended (P = 0.09) to have overall ADG, and had a 9.4% greater (P = 0.03) overall ADG in the last 78 d compared to CXH. There were no differences (P ≥ 0.44) between breeds for gain efficiency or net energy for maintenance or gain based on growth performance. Charolais cross steers had the lesser (P ≤ 0.04) average ruminal temperature during the months of June, July, August, and November, while there were no ruminal temperature differences in September and October (P > 0.10). Angus cross steers demonstrated an increase (P ≤ 0.04) in kidney, pelvic, and heart fat, backfat thickness, marbling, and yield grade compared to CXH; however, CXH had a larger (P = 0.01) longissimus muscle area. There were no other differences (P ≥ 0.11) in carcass characteristics, health, or liver abscesses between breeds. Results indicate that biochar supplementation at 0.20% (DM basis) did not affect growth performance or carcass characteristics; however, breed (Angus vs. Charolais) used in a beef on dairy cross did affect carcass characteristics, including carcass weight, and muscle and fat deposition; showing the importance of proper breed selection when a beef on dairy crosses production.