| |
Gilts and sows
|
|---|
|
Explanatory variables
|
N
|
SRB risk (99% CI)
|
|---|
|
Parity groups
|
|
0
|
93,604
|
0.92 (0.67–1.26)a
|
|
1
|
78,243
|
0.49 (0.35–0.68)b
|
|
2–5
|
229,859
|
0.24 (0.17–0.34)c
|
|
6 or more
|
52,352
|
0.11 (0.07–0.18)d
|
|
First-served month group
|
|
Jan.-Mar.
|
113,178
|
0.29 (0.21–0.42)b
|
|
Apr.-Jun.
|
114,322
|
0.30 (0.21–0.44)b
|
|
Jul.-Sep.
|
112,615
|
0.40 (0.27–0.56)a
|
|
Oct.-Dec.
|
113,943
|
0.29 (0.20–0.41)b
|
|
Herd productivity groups
|
|
Low-performing herds
|
65,565
|
1.30 (0.73–2.22)a
|
|
Intermediate-performing herds
|
196,848
|
0.57 (0.37–0.85)b
|
|
High-performing herds
|
191,645
|
0.11 (0.06–0.21)c
|
|
WMI groups1
|
|
WMI 0–6 days
|
315,071
|
0.26 (0.19–0.39)b
|
|
WMI 7–12 days
|
22,633
|
0.36 (0.23–0.57)a
|
|
WMI 13 days or more
|
22,750
|
0.27 (0.15–0.42)ab
|
-
CI confidence interval, WMI weaning-to-first-mating interval
-
a-cMean values within a group with different letters are different (P < 0.05)
-
1The WMI groups were compared in the model containing sows only (N = 360,454)
