Risk factors for intrapartum stillbirth in piglets born from cloprostenol-induced farrowing sows

Figures & data

Table 1. Descriptive statistics of 77 investigated sows and 1004 piglets.

Parameters	Number	Mean ± SD/Percentage
Parity	77	3.7 ± 2.0
Gestation lengh (day)	77	115.2 ± 0.71
Litter size	77	13.2 ± 4.1
Farrowing duration (minute)	77	249.9 ± 122.9
Birth interval^a (minute)	927	19.3 ± 31.4
Individual birth weight^b (g)	983	1473 ± 377
Crown-rump length^b (mm)	983	267 ± 26
Body mass index^b	983	17.9 ± 4.8
Ponderal index^b	983	71.5 ± 16.1
Incidence of stillbirth at litter level (%)	77	36.4 (28/77)
Total stillbirth rate^c (%)	1004	5.3 (53/1004)
Non-fresh stillbirth (%)	53	7.5 (4/53)
Prepartum stillbirth (%)	53	13.2 (7/53)
Intrapartum stillbirth (%)	53	79.2 (42/53)
Mummified rate^c (%)	1004	2.1 (21/1004)

^a Exclusion of 77 firstborn piglets.

^b Exclusion of 21 mummified piglets.

^c Inclusion of all piglets.

SD: standard deviation.

Table 2. Univariate and Multivariate Generalized Linear Mixed Models for the association between potential risk factors and intrapartum stillbirth (dependent variable) of piglets (n = 898) born within 77 cloprostenol-induced farrowing sows.

Variables	Univariate	Multivariate (final model)
	OR (95%CI)	OR (95%CI)
Birth order	1.22 (1.13-1.32)****	1.24 (1.13-1.37)****
Birth weight deviation (100g)	0.82 (0.74-0.91)****	0.78 (0.69-0.88)****
Birth interval (minute)	1.01 (1.00-1.02)***	1.01 (1.01-1.02)****
Ponderal index	0.91 (0.88-0.95)****	0.95 (0.91-0.99)***
Parity	1.20 (0.97-1.48)*
Gestation length (day)	1.15 (0.74-1.80)
Litter size	1.10 (0.98-1.22)
Cumulative farowing duration (minute)	1.01 (1.00-1.01)***
Birth weight (100g)	0.84 (0.77-0.92)***
Crown-rump length (cm)	0.95 (0.84-1.07)
Body mass index	0.75 (0.65-0.86)***
Female	1
Male	1.04 (0.55-1.96)

The final forward GLMM consisting of birth order, birth weight deviation, birth interval, and ponderal index best explains the variation of the intrapartum stillbirth of piglets born from cloprostenol-induced farrowing sows. The marginal R² and conditional R² of the final model were 0.31 and 0.54, respectively. The P-value of the final model was <0.001. Hosmer-Lemeshow goodness of fit test had a p-value = 0.637. OR: odds ratio, CI: confidence interval, P: probability level. *, **, ***, and **** denoted the significance level <0.1, 0.05, 0.01, and 0.001, respectively. For the final model, τ²= 1.583 and VPC (or ICC) = 0.325.

Data availability statement

The data presented in this study are available on request from the corresponding author.