Klöver i ensilage till suggor - effekter på reproduktion och produktivitet
The weather has been extremely rainy the last summers in Sweden. Because of the rain, a lot of harvested straw has been lost since it was too wet to store. When the pig producers couldn?t get enough straw to use as bedding, an alternative was requested. Silage is a realistic alternative to straw but since silage often contains clover, it may not be suitable to use in pig production since clover is rich in phytoestrogens. Compared to the most common clover species cultured in Sweden, red clover (Trifolium pratense) contains most phytoestrogens. It has been reported that clover has caused fertility issues in both cattle and sheep but it is still unknown how clover affects the fertility of sows. However, hormonal changes have been reported in sows that have eaten the same amount phytoestrogens they would normally eat with a diet including soy beans (Glycine max). Since the main phytoestrogens in red clover have a less estrogenic activity than the main phytoestrogens in soy beans, the results are not fully comparative with a diet containing red clover. Sows tend to be less sensitive to phytoestrogens than ruminants. It also seems that phytoestrogens also could have a positive impact on pig production. More research is needed but until then, cautious feeding with red clover silage is recommended.