Relationship between piglets' survivability and farrowing kinetics in hyper-prolific sows

Abstract

Background: Prolonged farrowing and more piglets born with low birth weight are undesirable consequences of genetic selection for increased litter size. The objective of the present observational study was to evaluate the relationship between piglets' survivability and farrowing kinetics in hyperprolific sows. A total of 58 sows of different parities and 1190 piglets were included. The entire farrowing process was monitored and the following parameters were recorded: inter-piglet birth interval, birth order, total born, live born, dead born, and mummified piglets, obstetric intervention, weight at birth and 24h, colostrum yield and intake.

Results: The sows included in this study had on average 20.6 ± 0.6 total piglets born, of which 16.4 ± 0.6 were live born, 3.3 ± 0.4 were stillborn and 0.9 ± 0.2 were mummified piglets. The average farrowing duration and average birth interval were 411.3 ± 31.6 and 20.6 ± 1.7 min, respectively. Farrowing duration was positively associated (p < 0.05) with parity, number of stillborn and mummified piglets. Piglet mortality 24h after birth was negatively affected (p < 0.01) by birth weight and positively affected (p < 0.01) by cumulative birth interval. The last tercile of piglets born (birth order ≥ 17) had the highest (p < 0.01) inter-piglet birth interval (IPBI) (43.4 ± 4.17 min) compared to piglets born in the first (birth order between 2 and 7) (26.5 ± 3.8 min) and second (birth order between 8 and 16) terciles (21.9 ± 3.8 min). Cumulative birth interval, birth weight, occurrence of stillborn piglets and manual intervention were positively associated (p < 0.05) with IPBI. Piglet birth weight was also positively associated (p < 0.01) to individual colostrum intake. Piglets ingesting more colostrum had lower (p < 0.01) mortality from 24h after birth until weaning. Sow's parity and cumulative birth interval were positively associated with the presence of stillborn piglets (p = 0.02 and p < 0.01, respectively).

Conclusion: Reducing farrowing duration may be crucial to decrease stillbirth rate and neonatal mortality in hyperprolific sows. Moreover, special care must be provided to the lighter piglets within a litter to increase their colostrum intake and minimize piglet's mortality throughout lactation.

Keywords: Colostrum; Hyperprolific sow; Inter-piglet birth interval; Mortality; Survivability.

Fig. 1

Inter-piglets birth interval (min) according to birth order. A Inter-piglet birth interval according to birth order grouped by terciles. Birth order between 2 and 7 was considered as the first tercile (1/3; n = 464 piglets) of piglets born, birth order between 8 and 16 was considered the second tercile (2/3; n = 430 piglets) and birth order between 17 and 25 was considered the last tercile (3/3; n = 279 piglets)). B Inter-piglet birth interval for each birth order. The birth interval of the first piglet (birth order 1) was not included as it was considered as zero. Data are presented as mean ± SEM. Different letter means statistical significance at p < 0.01

Fig. 2

Univariable regression models showing the association between farrowing duration and percentage of mummified piglets per litter (A), parity (B) and percentage of stillborn per litter (C)

Fig. 3

Probability of piglets being alive until 24h post-farrowing according to their respective cumulative birth interval. 983 piglets were included in this analysis. Stillborn and mummified piglets were not included

Fig. 4

Probability of piglets being alive during farrowing according to the cumulative birth interval