Table 5.

Effects of weaning age and AB program on performance in the overall period (weaning to marketing)¹

	Weaning age, d
	18.5		21.5		24.5
	Diet						Probability, P-value<
Item	NAE	AB	NAE	AB	NAE	AB	SEM	AB	Linear age	Quadratic age	Linear age × AB	Quadratic age × AB
BW, kg
Weaning	4.77	4.82	5.45	5.45	6.18	6.18	0.086	0.972	<0.001	0.650	0.886	0.888
197 d of age	130.6	131.0	132.6	133.4	133.1	135.5	1.57	0.182	<0.001	0.537	0.357	0.737
Birth to 197 d of age
ADG, g	659	659	668	673	668	682	9.1	0.170	0.001	0.547	0.333	0.819
Wean to 197 d of age
ADG, g	695	705	718	732	736	755	7.3	0.009	<0.001	0.467	0.510	0.945
ADFI, g	1,668	1,664	1,691	1,736	1,709	1,773	20.5	0.031	<0.001	0.320	0.079	0.580
G:F, g/kg	417	424	426	422	429	424	15.0	0.903	<0.001	0.324	0.005	0.209
Treated2, %	34.4	35.4	33.1	27.0	18.0	16.1	4.42	0.238	<0.001	<0.001	0.514	0.272
Losses3, %	8.8	7.6	8.8	5.4	7.9	5.9	1.18	<0.001	0.097	0.725	0.508	0.080
Weight sold/pig weaned4, kg	118.5	120.9	119.9	126.1	122.0	127.2	2.86	0.019	0.050	0.481	0.535	0.540

¹A total of 2,184 pigs (DNA 600, Columbus, NE × PIC L42, Hendersonville, TN) were used with 14 pens per treatment and 26 pigs (13 barrows and 13 gilts) per pen. The AB program included 441 mg/kg CTC from day 8 to 21 and 22 mg/kg of BW per day at week 7 postweaning via drinking water for five consecutive days (AB) or NAE.

²Percentage of pigs treated with injectable ABs.

³Sum of mortality and removed pigs (pigs identified as nonambulatory, not responding to medical treatment).

⁴Weight sold per pig weaned = (final BW * final number of pigs per pen)/number of weaned pigs needed to fill one finishing pen.