Risk Factors Associated with the Occurrence of the Second-Litter Syndrome in Sows in Southeastern Mexico

Table 1

Factors associated with the second-litter syndrome in three pig farms in Yucatan, Mexico, using a binomial logistic model.

Factor	𝑁	Estimate	Standard error	Odds ratio	95% Confidence limits
Farm
1	1893	0		1
2	843	0.442	0.105	1.55	1.26, 1.91
3	1560	0.697	0.092	2.01	1.68, 2.41
Year of farrowing
2003	363	0		1
2004	307	0.166	0.182	1.18	0.83, 1.69
2005	600	0.504	0.158	1.66	1.21, 2.26
2006	414	0.232	0.168	1.26	0.91, 1.75
2007	418	0.129	0.169	1.14	0.82, 1.59
2008	405	0.114	0.171	1.12	0.80, 1.57
2009	623	0.040	0.158	1.04	0.76, 1.42
2010	577	0.258	0.158	1.29	0.95, 1.76
2011	589	0.224	0.156	1.25	0.92, 1.70
Season of farrowing
Dry	1360	0.180	0.087	1.20	1.01, 1.42
Rainy	1381	0.212	0.090	1.24	1.04, 1.47
Windy	1555	0		1
Number of pigs born alive
<9	1097	0		1
9-10	1179	1.29	0.096	3.63	3.01, 4.38
11-12	1086	2.25	0.105	9.51	7.75, 11.7
>12	934	3.50	0.134	33.24	25.6, 43.2
Lactation length (days)
<18	176	0.323	0.205	1.38	0.92, 2.06
18–24	3631	0.203	0.115	1.23	0.98, 1.54
>24	489	0		1
Weaning to conception interval (days)
<4	1505	0.577	0.091	1.78	1.49, 2.13
4–11	1344	1.01	0.092	2.74	2.29, 3.28
>11	1447	0		1