PROVIDING enrichment such as straw or lucerne hay two days before farrowing can enhance the contentment or affective state of older sows housed in traditional farrowing systems and reduce still birth rates.
This is the conclusion from Australian studies into ways to measure and increase sow contentment.
The University of Melbourne-led research aimed to identify indicators of contentment in sows, test their practicality in production settings, and assess how the provision of enrichment affects sow contentment, behaviour and performance in farrowing crates.
The big study also included the South Australian Research and Development Institute, Sun Pork Farms South Australia and livestock feed producer Rivalea Australia.
The project involved two experiments. One conducted in a research piggery involved best practice provision of lucerne hay daily during farrowing and lactation to test the effect of enrichment on sow contentment welfare indicators.
The other took place at a commercial piggery to assess different types of enrichment – lucerne, straw and non-nutritive cotton rope; either only during farrowing or over the course of lactation – on sow contentment and performance and the practicality and robustness of welfare indicators under commercial conditions.
A third independent study involved a control and sows offered lucerne chaff during and after farrowing.
In all studies, the provision of enrichment altered sow behaviour and the straw and lucerne treatments reduced still birth rates.
In the commercial study, control sows exhibited less sham chewing and pain-related behaviours than those on the enrichment treatments.
There was also an indication that enriched sows had a higher subsequent farrowing rate (FR) than controls, with FR for the control and the hay treatment for two days before farrowing averaging 84 per cent and 93 per cent respectively.
The researchers say the findings suggest that enriching the environment of sows housed in farrowing crates before and after farrowing changes their behaviour and biological function – the latter being expressed as reduced stillbirths and in increased colostrum intake and preweaning growth performance.
“Establishing the impacts of enrichment on cognitive behaviour and affective state requires further investigation,” the study says.