Table 3.

Quartiles for sow and piglet characteristics associated with stillborn rate, experiment 1

Litter weight1, kg	<18.1	18.1 to 21.2	21.3 to 23.9	>24	SEM	P-value
Stillborn, %	4.9c	6.0bc	7.1ab	8.6a	0.55	<0.001
Mean pig birth weight1, g	<1,300	1,300 to 1,420	1,430 to 1,570	>1,580	SEM	P-value
Stillborn, %	8.8a	6.7ab	5.7b	5.9b	0.53	0.011
Farrowing duration1, min	<162	162 to 224	225 to 307	>308	SEM	P-value
Stillborn, %	4.5c	5.9bc	6.8b	9.3a	0.60	<0.001
Sow BW day 1131, kg	<236	236 to 266	267 to 292	>292	SEM	P-value
Stillborn, %	5.7b	5.9b	7.2ab	8.4a	0.64	0.036
Total born2	<13	13 to 14	15 to 16	>16	SEM	P-value
Stillborn, %	4.7c	5.7bc	7.1b	10.5a	0.51	<0.001
Birth order ranking2	<25	25 to 50	50 to 75	>75	SEM	P-value
Stillborn, %	1.6d	3.2c	6.4b	18.7a	0.50	<0.001

¹A total of 473 sows were categorized into quartiles within each response variable, with each quartile representing ~25% of sows in the study population.

²A total of 6,939 piglets (6,458 live-born and 481 stillborn) were categorized into quartiles within each response variable, with each quartile representing ~25% of sows or piglets in the study population.

^a–dMeans within a row not sharing a common superscript differ, P < 0.05.