Technical Abstract: The classic technology of artificial insemination (AI) often requires insemination doses to be kept for more than 24 h, with a requirement that the degree of progressive motility at the moment of insemination not be below 65%. The aim of this paper was to determine the influence of breed, sperm concentration, and storage time on the fertilization capacity of extended semen from native ejaculates of boars. The research included the following boar breeds: Duroc (n=34), Hampshire (n=30), Large White (n=42), and Swedish Landrace (n=32) from large pig farms in Vojvodina (Republic of Serbia). Two ejaculates were collected from each boar once per month for 12 months (a total of 24 ejaculates per boar). There was statistically significant (p<0.01) influence of breed on the number of sperm samples that maintained more than or equal to 65 progressive motility during 48 h of storage in 1:4 dilution. There was also an influence of sperm concentration on progressive motility. As sperm concentration increased during storage, more than or equal to 65% progressive motility declined (P=0.01) within 24 h. The results show that it is necessary to determine the adequate dilution rate and storage time for each ejaculate, while taking into account sperm concentration in the native semen.