Table 3.

Effect of long-term aspirin (50 mg/kg of body weight daily for 159 d) on performance of beef steers (experiment 2)

	Treatment1
Item	Control	Aspirin	SEM	P-value
n, individual (pen)	48 (8)	48 (8)	—	—
Body Weight2,4, kg
Day 0	355.2	354.6	4.88	0.93
Day 85	520.4	516.7	4.88	0.59
Day 159	621.3	612.6	4.88	0.21
Average daily gain3,4, kg/d
First half (day 0 to 85)	1.94	1.91	0.050	0.61
Second half (day 86 to 159)	1.39	1.27	0.050	0.09
Overall (day 0 to 159)	1.69	1.61	0.035	0.10
Dry matter intake2,4, kg/d
First half (day 0 to 85)	9.4	9.5	0.21	0.71
Second half (day 86 to 159)	10.3	10.1	0.21	0.39
Overall (day 0 to 159	9.8	9.8	0.18	0.84
Gain:feed2,4
First half (day 0 to 85)	0.206	0.200	0.0048	0.35
Second half (day 86 to 159)	0.135	0.126	0.0048	0.19
Overall (day 0 to 159	0.173	0.164	0.0038	0.15
Days on feed	158	161	4.5	0.59

¹Control, no aspirin inclusion; aspirin, 0.25% of diet dry matter daily as aspirin.

²No repeated measures treatment effect (P ≥ 0.19).

³Repeated treatment effect (P = 0.09).

⁴No repeated measures treatment × time effect (P ≥ 0.24).