Growth performance, carcass characteristics, and fatty acid composition of Angus- and Wagyu-sired finishing cattle fed for a similar days on feed or body weight endpoint

Wagyu-sired cattle selected for either growth or marbling potential were compared with Angus-sired cattle for feedlot performance, carcass characteristics, and fatty acid profile when slaughtered after a similar number of days on feed or body weight endpoint. The selection of growth potential within Wagyu sire resulted in more similar feedlot performance compared with the Angus-sired cattle; while selection for marbling potential within Wagyu sire resulted in a lesser feedlot performance, but more desirable beef carcass quality compared with Angus-sired cattle. Lay Summary Wagyu-sired steers and heifers (WA) from two different sires, selected for either growth (G) or marbling (M), and Angus-sired steers (AN) were fed for a similar days on feed (D) or to a similar final body weight (B) in two independent experiments. In experiment 1, Angus-sired steers were compared with Wagyu-sired steers and heifers when fed for a similar number of days on feed (DOF; WA-GD and WA-MD) and in experiment 2, AN were compared with Wagyu-sired steers and heifers at a similar final body weight (BW; WA-GB and WA-MB). In experiment 1, AN and WA-GD cattle had a greater rate of gain and final BW compared with WA-MD cattle. AN cattle consumed more feed compared with Wagyu-sired cattle. WA-MD had the greatest amount of kidney fat and polyunsaturated fatty acid (FA) compared with AN and WA-GD cattle. In experiment 2, AN cattle had a greater rate of gain, feed intake, with fewer DOF compared with Wagyu-sired cattle. At a similar final BW, WA-MB cattle deposited more kidney fat, marbling at the 6th- and 12th-rib, and backfat at the 6th-rib compared with AN cattle. The FA profile of the longissimus muscle from WA-MB cattle had more polyunsaturated FA, with less saturated FA compared with AN cattle. The resulting feedlot performance and carcass characteristics vary depending on the selection of Wagyu sire for growth or marbling ability. This study evaluated the feedlot performance, carcass characteristics, and fatty acid (FA) composition of Wagyu-sired and Angus-sired cattle at a similar days on feed (D) or body weight (B) endpoint. Wagyu-sired steers and heifers (WA) from two different sires, selected for either growth (G) or marbling (M), were compared with Angus-sired steers (AN, n = 13) in two independent incomplete-block design experiments at a similar days on feed (DOF; WA-GD, n = 9; WA-MD, n = 12) in experiment 1 or similar final body weight (BW; WA-GB, n = 9; WA-MB, n = 13) in experiment 2. Cattle were offered a corn silage-based growing diet for 119 d before being transitioned over 3 wk to a finishing diet. Data were analyzed as a randomized incomplete block design. In experiment 1, AN and WA-GD cattle had a greater (P < 0.01) off-test BW and average daily gain (ADGP < 0.04) than WA-MD cattle and AN had a greater dry matter intake (DMI; P < 0.02) than WA-GD and WA-MD cattle. The AN and WA-GD cattle had a greater carcass weight (P < 0.02) than WA-MD cattle. Percent kidney, pelvic, and heart fat (KPH) was greatest (P < 0.01) for WA-MD cattle, followed by WA-GD cattle, and lastly AN cattle. Total lipid (P < 0.03) and polyunsaturated FA (PUFA; P < 0.01) percentage were greater for WA-MD-cattle than AN and WA-GD cattle, as they tended (P = 0.11) to have the greatest 12th rib marbling score. In experiment 2, AN-cattle needed fewer (P < 0.01) DOF and had a greater (P <= 0.02) ADG, DMI, and gain:feed than WA-GB- and WA-MB-cattle. The WA-MB-cattle had a greater (P < 0.01) 12th and 6th rib marbling score, USDA quality grade, and 6th rib backfat thickness than AN-cattle. Compared with AN cattle, WA-GB cattle had a greater (P <= 0.01) percent KPH and lesser (P <= 0.03) rib thickness. The WA-MB-cattle had a greater (P <= 0.01) concentration of total lipid and PUFA than AN- and WA-GB-cattle, and lesser saturated FA (SFA; P < 0.01) concentration than AN-cattle in the longissimus muscle (LM). The 6th rib location of the LM had a greater (P <= 0.01) percentage of total lipid and SFA, but less (P < 0.03) MUFA compared with the 12th rib location. In conclusion, Wagyu-sired cattle selected for marbling potential had a lesser ADG, DMI, more marbling, more PUFA, and less SFA in the LM than Angus-sired cattle regardless of slaughter endpoint. Wagyu-sired cattle selected for growth potential had a similar ADG and carcass characteristics compared with Angus-sired cattle when fed for a similar number of days on feed.