The present invention relates to the use of 25-hydroxy vitamin D3 to improve animal fertility. More particularly, the invention relates to the use of 25-hydroxy vitamin D3 for improving the quality of semen and/or conception rate in animals including men. In a preferred embodiment the invention relates to the use of 25-hydroxy vitamin D3 for improving the quality of semen in male and the conception rate in female animals as for example cattle, dogs, cats and horses, preferably pigs.本發明係關於一種25－羥基維他命D3於改善動物繁殖力之用途。更特定言之，本發明係關於25－羥基維他命D3用於改善包括人之動物的精液品質及/或受孕率之用途。在一較佳具體實施例中，本發明係關於25－羥基維他命D3用於改善例如牛、狗、貓及馬、較佳豬之雄性動物精液品質及雌性動物受孕率之用途。
