Table 2.

Effects of trace mineral injection and dietary vitamin E supplementation on growth performance of feedlot heifers¹

Item	Treatment2,3					P-value
	Cont + Sal	Cont + MM	Vit E + Sal	Vit E + MM	SEM	Diet	Injection	Diet × Injection
Total head, n	12	12	11	11
BW, kg
Initial	425	422	427	421	9.1	0.98	0.66	0.89
Day 28	469	464	464	469	9.7	0.99	0.95	0.62
Day 56	500	499	502	503	9.5	0.79	0.99	0.93
Final	538	543	536	544	10.3	0.98	0.51	0.91
Total BW gain, kg	112	121	110	123	6.4	0.94	0.09	0.72
Days 0 to 28
ADG, kg/d	1.53	1.44	1.31	1.64	0.14	0.96	0.36	0.12
DMI, kg/d	8.7ab	8.3ab	7.5b	8.9a	0.5	0.67	0.27	0.03
G:F	0.17	0.17	0.16	0.18	0.01	0.98	0.48	0.44
Days 29 to 56
ADG, kg/d	1.09	1.26	1.33	1.22	0.12	0.48	0.73	0.12
DMI, kg/d	8.8	8.7	8.6	9.5	0.4	0.55	0.23	0.13
G:F	0.12b	0.14ab	0.16a	0.13ab	0.01	0.31	0.74	0.02
Days 57 to 89
ADG, kg/d	1.17	1.37	1.07	1.29	0.12	0.47	0.07	0.93
DMI, kg/d	8.6	8.8	8.2	9.4	0.3	0.81	0.04	0.17
G:F	0.14	0.15	0.13	0.14	0.01	0.47	0.29	0.49
Days 0 to 89
ADG, kg/d	1.26	1.36	1.23	1.38	0.07	0.94	0.09	0.73
DMI, kg/d	8.7	8.6	8.1	9.3	0.4	0.96	0.12	0.08
G:F	0.15	0.16	0.15	0.15	0.01	0.80	0.29	0.23

¹Trace mineral injection included 15 mg/mL of Cu, 10 mg/mL of Mn, 5 mg/mL of Se, and 60 mg/mL of Zn.

²Heifers were supplemented with no additional vitamin E in the diet (Cont) or 1,000 IU of vitamin E·heifer⁻¹·d⁻¹ (Vit E) for 89 d prior to slaughter. Heifers received saline (Sal) or trace mineral injection (TM) at a dosage of 1 mL/68 kg BW at day 1 of the 89 d feeding period.

³Treatments within day lacking common superscripts differ (P < 0.05).