The practice of cross-fostering has been associated with a lower risk of pre-weaning mortality in piglets. Moving pigs from the second day, as well as lower birth weight, were associated with a higher risk.
These conclusions were drawn by researchers from the Danish Pig Research Centre (VSP), part of SEGES and the Danish Agriculture & Food Council. The results were presented at the International Pig Veterinary Society (IPVS) Congress in Dublin, Ireland, in early June 2016.
Connection cross-fostering and mortality
The Danish researchers investigated a possible connection within a wider programme to combat pre-weaning mortality. Since Denmark is known for its highly prolific sows, relatively high numbers of piglets do not make it to weaning. The industry therefore decided to reduce the mortality by 20% before 2020, compared to the 2011 level.
In their oral presentation, the scientists explained that their hypothesis was that cross fostering, later movements and birth weight of pigs were associated with preweaning mortality. The study was performed in 9 farrow-to-finish herds with more than 1.8 stillborn piglets per litter. About 70 consecutive farrowings in each herd were included in the study.
Definition of cross-fostering
For the study, the scientists defined 'cross-fostering' as movements of pigs on the day of birth. Movements from day 2 were analysed separately, and both processes were analysed separately. Birth weight was also included as co-variate, they wrote.
All in all, in the statistical analysis 8,611 liveborn piglets were included, and 1,615 piglets died in the farrowing units (18.3%). The scientists write that on the day of birth 26% of the piglets were cross-fostered. In addition, between day 2 and day 20, 30% of the piglets were moved.
Lower and higher risks
When comparing, the researchers found that cross-fostered pigs had about 23% lower risk of dying before weaning. Conversely, moved pigs after day 1 had about 2.5 times higher risk of dying before weaning.
The research was carried out by Markku Johansen and Poul Baekbo, Pig Research Centre/SEGES, Kjellerup, Denmark; and Jan Dahl, Danish Agriculture & Food Council, Copenhagen, Denmark.