SILAGE IN DIETS FOR ORGANIC SOWS IN GESTATION

Summary

This study was conducted to determine whether the supply of grass silage or grass silage mixed with barley or CCM to organically raised gestating sows would allow a reduction of compound feed allowance without loss in animal performance. On average, sows fed grass silage or mixed silage were able to compensate for a pre-set reduction of 1 kg or 1.5 kg compound feed, respectively. However, the variation in silage intake between individual sows was large, with a number of mainly young sows consuming less silage than the required amount. Consequently, these sows showed a net back fat loss during the experimental period from d 7 of gestation to weaning. Our results indicate that more feeder space than 1 for 8 sows is required to allow adequate silage intake in group housed sows. From this study we cannot derive whether that would be also allow young sows to realise an adequate silage intake. In conclusion, it seems possible to replace 1 kg compound feed by free access to grass silage and 1.5 kg compound by mixed barley or CCM silage, provided that variation between sows is reduced and young sows would also be able to ingest an adequate amount of silage.