Update on Omega-3 Fatty Acids and Litter Size in Swine

another. Nutritionists have been examining the health benefits of specific fatty acids, especially omega-3 fatty acids, in pet and human health for several years. The omega-3 fatty acids are linolenic; eicosapentaenoic (EPA); and docosahexaenoic, (DHA). Linseed (flaxseed) is the most abundant source of linolenic acid; canola oil is the next best source, while negligible amounts are found in the other sources of fats and oils. In contrast, fish oils are the only sources of the other two omega-3 fatty acids (EPA and DHA). The role that omega-3 fatty acids may have in swine reproduction has been investigated. A review of those research results were presented in the 2003 Nebraska Swine Report (available at review was prepared research results from two experiments have been published. Therefore, a re-evaluation of the role of omega-3 fatty acids in sows diets is warranted. Researchers at United Feeds Inc. fed 338 primiparous and multipa-rous sows either a corn-soybean control diet or the control diet top-dressed with Fertilium TM , a protected omega-3 fatty acid source. Fertilium TM was top-dressed at the rate of 85 g/day beginning 5 + 2 days before farrowing through to day 7 postweaning for a total of 35 days. Sows were mated at first estrus after weaning. All sows received a common diet throughout gestation until subsequent far-rowing. Sows that received Fertilium TM farrowed significantly more total (11.6 vs 11.0) and live pigs (10.8 vs 10.3) than control sows. University of Manitoba and Minnesota researchers fed 243 multiparous sows either a barley/ wheat-canola meal control diet or the control diet with 5% flaxseeds (rich source of linolenic acid) from breeding to weaning. Litter size born alive was not significantly improved by feeding flaxseeds; however, sows fed flaxseeds weaned more pigs than those fed the control diet (10.4 vs 9.1). In addition, pigs from sows fed flaxseeds were significantly heavier at weaning than those from control sows (10.6 vs 9.5 lb). A summary of research results published to date on the effect of omega-3 fatty acids on litter size is presented in Table 1. In all but one of the studies reviewed, the number of pigs born alive improved (0.2 to 0.7 pigs litter) when sows were provided diets that contained more omega-3 fatty acids. In all the studies that reported litter size at weaning, positive responses were observed (0.3 to 1.3 pigs/litter) with omega-3 fatty acid supplementa-tion. Previous research suggests that …