Distribution of pre-weaning mortality in 20,920 pigs and effectiveness of an isotonic protein drink intervention

Authors:

Ava Firth and Stefan Buzoianu

Introduction

Pre-weaning mortality (PWM) as a proportion dead pigs out of the born alive, not including the stillborn) is a widely recognisedproblem in commercial swine production, averaging 12–14% worldwide. In production terms, assuming 13% PWM and 14.1 born alive, as worldwide averages, pig producers are losing almost two piglets per litter before weaning. Since dead piglets are oftenlighter than their live counterparts, there is a widely held perception in swine production, that low birth weight piglets are mainly responsible for most of the PWM losses. This is why, to reduce production costs, it is mainly these small pigs who are targeted forlife-saving interventions (e.g. supplementation with electrolytes, bio-actives, milk, or colostrum). However, it has not been clearwhether dead pigs were just born light or whether they lost condition between birth and death, giving rise to the perceptionthat it is only the small pigs that die. Our aim was to investigate the pre-weaning mortality rates of pigs when stratified by birthweight. Further, we investigated the effect of an intervention (Tonisity Px –TPX) on pre-weaning mortality – again, stratified by birth weight. Tonisity Px is an isotonic protein drink that provides hydration, electrolytes and key bioactives to the neonatal piglet intestine.

Materials and methods

The data originates from 15 studies (N = 20 920 piglets) conducted by Tonisity on commercial farms from 2015 to 2021. Forassessing the effect of TPX on piglet PWM, sows and their litters were randomly allocated to either Control or supplementationwith TPX. From day 2 (24 hours of life) to day eight of age, TPX piglets were offered 500 ml/day of a 3% TPX solution in an openfeeding pan. Piglets were individually weighed at birth. Litter information (parity, litter size, sow ID) and individual piglet PWMwas recorded for all litters. Individual birth weights were used to categorize pigs as Light (L-pigs, <1 kg), Medium (M-pigs, 1–1.6kg), and Heavy (H-pigs, >1.6 kg). The effects of TPX on PWM were analysed by a logistic regression model (PROC GLIMMIX, SAS9.4, SAS, Cary, NC, USA). Study and sow ID were included as random effects in the analysis. Treatment, and the treatment x birthweight category interaction were included as fixed effects and litter size was included as a covariate in the model. In 13 out of the15 studies, (N = 18 085 pigs), parity and gender distribution not significantly different between treatments (P > 0.05). Therefore,parity and piglet gender were not included as covariates in the overall analysis since this information was not available for allof the studies.

Results

L-pigs were 11% of the population. M-pigs were 54% and H-pigs were 35% of the population. Pre-weaning mortality across the entire population averaged 30% in L-pigs, 8% PWM in M-pigs and 2.7% in H-pigs. Of all pigs that died pre-weaning, 67% wereM- and H-pigs (>1 kg birth weight). Tonisity Px reduced overall PWM by 17% from 10.2% to 8.5% (P < 0.01, SEM 0.82%, N = 20920 pigs, 15 studies). Pre-weaning mortality was reduced significantly for the Medium pigs (P = 0.01; 18% reduction, 54% of the population) and numerically for the Light (13% reduction) and Heavy (20% reduction) pigs (Fig. 1)

Conclusion and implications

The results confirmed the hypothesis that it is not only the small pigs that die before weaning. These results challenge the industryfocus of rescuing the small piglets and make a clear case for widening neonatal interventions across the entire population, toinclude M- and H piglets. Tonisity Px, an isotonic protein drink administered in the first week of life was shown to reduce PWMregardless of birth weight.The PWM reduction was 13% in L-pigs, 18% in M-pigs and 20% in H-pigs. Therefore, we propose this isotonic protein drink as aviable intervention to maximise piglet pre-weaning survival.

Acknowledgements

We acknowledge technical support from Tests and Trials in Spain.