Method for the preparation of a feed for sows

摘要

The present invention relates to improvement of breeding efficiency of sows. The present invention povides an additive for the feed of sows containing as an active ingredient a reduced form of folic acid in the form of 7,8-dihydrofolic acid, leucovorin, liver powder, disrupted cells or cell extract of a microorganism, etc.; a feed for sows added with such as additive; and a method of breeding sows in which sows are orally administered with such an additive or fed with such a feed.