Table 4.

Effects of feeding ractopamine hydrochloride on carcass gain in Holstein steers

	Dose				P-value		Duration				P-value
Item	0	300	400	SEM	Linear	Quadratic	28	35	42	SEM	Linear	Quadratic
Actual HCW, kg	382.7	385.6	387.1	3.98	0.02	0.81	385.4	385.7	384.3	3.98	0.57	0.57
Initial HCW, kg1	356.9	356.2	355.6	3.25	0.40	0.71	360.9	356.0	351.9	3.25	<0.001	0.77
Carcass gain, kg2	25.5	29.6	31.3	2.57	0.001	0.34	24.3	29.6	32.4	2.57	<0.001	0.41
Gain over 0, kg	—	4.1	5.8				—	5.3	8.1
Carcass ADG, kg/d3	0.73	0.85	0.91	0.07	0.001	0.31	0.87	0.85	0.77	0.07	0.07	0.56
Carcass G:F4	0.076	0.089	0.095	0.008	0.002	0.98	0.090	0.088	0.082	0.008	0.30	0.53

¹Initial HCW calculated as follows: day 0 BW × 59.75%. HCW = hot carcass weight.

²Carcass gain calculated as follows: (actual HCW − predicted HCW).

³Carcass ADG calculated as follows: (carcass gain/duration). ADG = average daily gain.

⁴Carcass G:F calculated as follows: (carcass ADG/DMI). G:F = gain-to-feed ratio; DMI = dry matter intake.