The present invention relates to an oil composition for livestock feeds, which can promote growth of livestock since the composition is not accumulated in the livestock body and absorbed instantly, and then used as an energy source, to a feed additive for promoting the growth, a livestock feed composition and a method for breeding livestock using the same. The oil composition for livestock feeds contains 50 wt% or more of diglycerides including 10 to 90 wt% of fatty acid having 14 or less carbon atoms, and 10 to 80 wt% of fatty acid having 14 or less carbon atoms bonded in the 1,3-positions.본 발명은 가축 체내 축적되지 않고 곧 바로 흡수되어 빠르게 에너지원으로 이용되어 가축의 성장을 촉진할 수 있는 사료용 유지 조성물, 이를 이용한 성장 촉진용 사료 첨가제, 가축용 사료 조성물 및 가축 사육 방법에 관한 것이다.