The objective of this study was to compare the differences in boar sperm output between periods 1990-1997 and 2000-2007 using a large data set from artificial insemination centers. These data were analyzed: semen volume, concentration of spermatozoa, progressive motion of spermatozoa and proportion of abnormal spermatozoa. The period 2000-2007 showed an increasing trend of sperm quantity. In contrast, the stagnation or decreasing trend of sperm quality was recorded. In crossbreds, a lower manifestationof heterosis was observed as well.