Table 4.

Effects of antibiotics and low crude protein diets on backfat thickness, loin area, and depth¹.

Item	ATB−2		ATB+3		SEM	P-value
	18.5% CP4	13.0% CP5	18.5% CP4	13.0% CP5		ATB	CP	CP × ATB
73 day of age
Backfat thickness	5.30	5.39	5.22	5.59	0.130	0.641	0.089	0.293
Loin area	11.23	10.92	11.80	10.76	0.329	0.547	0.048	0.273
Loin depth	23.77	22.87	24.68	22.83	0.590	0.462	0.027	0.429
87 days of age
Backfat thickness	6.03	6.20	6.08	6.02	0.167	0.689	0.738	0.511
Loin area	16.12	14.54	16.02	14.32	0.554	0.773	0.006	0.912
Loin depth	29.48	28.88	30.43	28.46	0.682	0.706	0.073	0.330

¹Experimental medicated diets (ATB +) were fed from 59 to 73 d old. In the post-medicated period, all pigs were fed their respective crude protein (CP) control diets from 73 to 87 d of age.

²ATB -, diet without antibiotics.

³ATB +, diet with 100 mg/kg tiamulin and 506 mg/kg oxytetracycline.

⁴18.5% CP, diet with 18.5% of CP.

⁵13.0% CP, diet with 13.0% of CP.