Conclusions from a PROHEALTH study on French pig farms
Piglet mortality is one of the main issues of concern for the pig industry worldwide, resulting in decreased sow performance and significant economic losses. According to different studies on piglet mortality, crushing and stillbirths are considered as the most important causes of death. The risks for each specific cause of piglet death have not been fully explored. Moreover, current literature does not capture the differences which exist between individual farms and the contribution of these differences to the problem of mortality.
A study conducted by PROHEALTH on French pig farms provides new insights into this issue. All 146 farms sampled for this analysis have reported neonatal mortality issues and were part of an audit which has been conducted by CCPA group. The analysis included a total of 7,928 dead piglets from 40,101 born. An average of 18.1 ± 5.62 sows were sampled in each farm randomly, all the dead piglets of the sampled sows were necropsied. We found that six main causes of mortality represented 85% of the total piglet deaths, up to 48h after birth. These causes are, in order of significance :
The main causes of neonatal piglet mortality (Figure 1):
1. Death during farrowing 23%
2. Non-viable underweight piglets 21%
3. Death before or during farrowing with signs of sepsis 17%
4. Mummification 11%
5. Crushing 8%
6. Starvation 5%
7. Others 15%, which includes acute diseases, death before farrowing with signs of autolysis, anaemia etc.
Whilst crushing is a well-known cause of piglet mortality, it is actually not in the top three causes of mortality as might have been anticipated. Deaths which occurred either before or during farrowing were the main cause of loss and should be given more attention in terms of remedial strategies. Stillbirth resulting from death during farrowing was the leading cause of piglet mortality. However, stillbirths have a number of different causes and can be classified into 3 different categories (Figure 2):
- Deaths during farrowing (52%)
- Deaths before or during farrowing with signs of sepsis (39%)
- Deaths before farrowing with signs of autolysis on the internal organs (9%)
Our findings suggest that different factors contribute to the cause and potential prevention of stillbirth:
- Deaths during farrowing were reduced during the night, but this was not the case for the other causes of stillbirth. As farrowing assistance was not given during the night, this observation suggests that inappropriate management practices during farrowing may contribute to this specific cause of death.
- Deaths before farrowing were associated with lower piglet weights compared to the other causes of stillbirth.
If piglets survive the farrowing process, they are still at risk from death caused by starvation and crushing. We noticed a reduction in post-farrowing deaths from starvation during the daytime hours. This underlines the importance of farrowing and post-farrowing assistance which is provided during working hours, for example to encourage piglets to consume colostrum.
The weight of the piglet, the parity of the sow, the litter size, the cause of death of littermates and season were all identified as potential other risks for certain causes of piglet mortality. This highlights the importance of defining which pattern of piglet mortality is present on the farm.
We developed a methodology, based on statistical analyses, to classify the farms. The criteria considered for the classification of each farm were: the percentage of the 6 most common causes of neonatal piglet death identified in the study, the average weight of the dead piglets and the average litter size of the sows. Based on these criteria, we identified 3 different categories of farms (Figure 3). This classification will enable a better understanding of the similarities and differences between pig farms. We can then target their specific weaknesses and develop strategies better suited to help them reduce piglet deaths.