PERFORMANCE OF YOUNG BOARS DEPENDING ON THE LITTER SIZE

The material consisted of 60 hybrid boars, from line 990 ( ) and Pietrain breeds ( ), divided into two groups depending on the litter size in which they were born and reared - group: 7-10 piglets (average 8.8) per litter; group: 11-17 piglets (average 12.5) per litter. The mean body weight of 21 day of live piglets born and reared in larger litters was significantly (P 0.05) lower than among boars reared in smaller litters. This difference gradually diminished and at day 63 of life both gro- ups had the same average body weight. In the period from 63 to 180 day of life, the boars from smaller litters had a slightly lower rate of growth (statistically insignifi- cant). Boars reared in larger litters at 180 day of life were on average 3 kg heavier. There were no significant differences in fat thickness, lean meat and testicular vo- lume between the assessed groups of young boars. From boars reared in smaller litters ejaculates had a significantly higher (P 0.05) sperm concentration and total sperm volume.