In the PPS collaborating pig industry a new system for lactating sows and their piglets is being developed/tested to come to a commercially working system. In this system the sows are weaned after six weeks of lactation. To maintain a high farrowing index it is necessary to inseminate these sows during lactation. A good method to stimulate heat is applying “intermittent suckling” (IS).
This means that sows and piglets are separated from each other over a number of days for 10 hours per day. The sows will come into heat after about 5 days and are inseminated. A question arising from this fact is how to feed these sows which are pregnant but also lactating.
In 2013 a literature study has been conducted on feeding of lactating sows in welfare-friendly housing systems. In which the sows are already being inseminated during the lactation period. Conclusions were that not much is known yet about this phenomena. In theory a high feeding regime is wanted because the sows still needs a lot of energy for milk production. On the other hand however during early pregnancy a higher feeding regime Leeds to higher progesterone levels which can therefore increase the risk on embryonic mortality. The risk is then the highest with young sows.
Recent research shows that high feeding regimes in early pregnancy does not need to negatively affect embryonic survival per se. The question remains what the consequences of feeding regime are for lactating sows during early pregnancy on reproduction and weight development of the sows.
At SIC Sterksel research is being conducted on the effects of a high or low feeding regime for sows during the last 10 days of a 6 weeks lactation period, in which they are also pregnant with the next litter.
Aspects that are studied are:
- Weight and back fat thickness development of sows and piglets during the elongated lactation and of the sows in the following pregnancy.
- The farrowing rate of the sows after the first insemination
- The number of live and stillborn piglets in the next litter and
- The weight of these live and stillborn piglets.
The research will be conducted on individually housed sows in loose housing systems, to allow the sows more freedom in the last 2 weeks of a six weeks lactation.The tests will finish in the stables in January 2015 and results are being presented in a rapport in the first quarter of 2015.