Innovative research in Pork CRC Project 1A-111 by scientists from University of Melbourne, Rivalea Australia, SARDI and Sun Pork Farms into the contentment or affective state of sows housed in traditional farrowing systems suggested that providing enrichment as straw or lucerne hay two days before farrowing might enhance the affective state of older sows and certainly reduce still birth rate.

The project, ‘Developing ways to measure and increase sow contentment’, comprised two studies supported by Pork CRC and a third at SunPork Farms South Australia as part of an honours programme. All were conducted with sows in farrowing crates.

SARDI sows were offered lucerne hay as enrichment pre and post farrowing. In a large study at Rivalea the enrichment treatments included hanging cotton rope, straw for two days before farrowing and straw before farrowing and through lactation, lucerne hay for two days before farrowing and lucerne hay before farrowing and through lactation. At SunPork Farms, sows were offered lucerne chaff before farrowing and through lactation.

In all studies enrichment with lucerne hay or straw reduced still birth rate and in the study at SunPork Farms enrichment also increased colostrum intake and piglet weight at 7,14 and 21 days of lactation.

In the study at Rivalea, provision of straw or lucerne hay before farrowing (two days) and before farrowing and through lactation increased anticipatory behaviours to feeding in multiparous sows but not gilts, suggesting an improvement in affective state.

Former Pork CRC CEO Roger Campbell noted it was interesting that in the smaller SARDI study enrichment increased total nesting behaviours and reduced sham chewing.

“In the large Rivalea study there were no treatment effects on nesting behaviour and control sows exhibited significantly less sham chewing and pain related behaviours than sows offered the lucerne hay or straw enrichments,” Dr Campbell said.

“There was no effect of treatment on subsequent reproduction in any of the studies, but a tendency in the Rivalea study for enriched sows to have a higher farrowing rate than control sows.”

The studies were some of the first to explore the contentment/affective state of sows housed in traditional farrowing systems.

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