The aim of this study was to analyze environmental variations of the AI boar sperm output adjusted for other effects ( breed-station, age of boar, interval between two collections and individuality of boar). A total of 303,748 records of semen collections were utilised to estimate statistics of semen traits of 3,392 boars belonging to the following groups of breeds: dam breeds Czech Large White, Landrace, sire breeds Czech Meat Pig, Duroc, Large White, Pietrain, and crossbreds of sire breeds. Semen volume, percentage of abnormal spermatozoa, total number of spermatozoa and index of sperm efficiency was evaluated. In the monitored period the increasing trend of quantity of spermatozoa and in contrast decreasing trend of quality of spermatozoa were displayed in boars of dam breeds. The positive trends of quantity and quality of spermatozoa were recorded in boars of sire breeds. A decreased trend of quantity and quality of spermatozoa was recorded in crossbreds.