Tests with a system cooling breeding sows during lactation yielded positive results, researchers at the Dutch Wageningen University and Research Centre reported.
The research was carried out at the practical centre of Sterksel during 2006-2008, at the request of the Dutch product board for livestock and meat (PVV) and Nooyen Pig Flooring.
Sows in a breeding house having a cool sow system had a higher feed intake, reducing weight loss during lactation and improving piglet weight at weaning. This, in turn, also had a positive effect on the litter size in the next litter – and breeding results of the piglets. Economic advantage of the system, in this trial, was €13.30 per sow per year.
Conclusions In figures, by housing lactating sows and piglets on a cool sow systems, the researchers concluded that:
* Feed intake was higher during lactation, on average 0.3 kg/day.
* Sow weight loss was lower during lactation (on average 1.5%). There was, however, a seasonal effect. In summer this was 3.5% on average, in winter there was no difference.
* Piglet weaning weight was higher (up 0.4 kg). Here was a seasonal effect as well: in summer this was on average 0.5 kg and in winter 0.2 kg.
* The next litter yielded on average 1 more live pig.
The housing temperature in farrowing houses is usually higher than 22˚C due to the heat sows emit. In these circumstances, sows have difficulties emitting more body heat, which could lead to a lower feed intake. This could degrade milk production, in turn leading to a slower piglet growth.
This will also cause sow weight loss during lactation, causing negative results in reproduction. Cooling the sow’s floor may contribute to the sow’s thermical comfort. The cool sow system consists of a steel grid with solid floor elements and a cool water circuit (22˚C) underneath the lactating sow’s shoulders and neck.