The UK dairy industry currently suffers huge losses due to declining fertility. Although fertility in the sheep industry is good overall, the use of multiple ovulation and embryo transfer techniques would benefit from improved conception and embryo survival rates. Studies suggest that omega-3 supplementation may bring about a reduction in the secretion of prostaglandin F2α (PGF2α), which would favour the maintenance of the corpora lutea (CL) and hence, a successful pregnancy. Feeding fish meal to dairy cows has been found to improve pregnancy rates by 10% (Burke et al., 1997). Using sheep as a model, this study aimed to evaluate whether reproductive performance in ruminants is improved by feeding an algal source of omega-3 fatty acids, particularly docosahexaenoic acid (DHA, C22:6 n-3). The study was also structured to determine whether prostaglandin production is affected by supplementing diets with omega-3.