A. APOSTOLOV, S. SLANEV, A. STOIKOV and E. GINEVA
Agricultural Institute, BG-9700 Shumen, Bulgaria
CES, BG-8600 Yambol, Bulgaria
APOSTOLOV, A., S. SLANEV, A. STOIKOV and E. GINEVA, 2001. Investigation of some reproductive qualities in three and four-breed crosses in pigs. Bulg. J. Agric. Sci., 7: 635-638
The investigation was carried out with 460 litters of sows Landrace x Large White mated by boars from Landrace, Belgian Landrace, Duroc, Hampshire and the crosses Belgian Landrace x Duroc and Belgian Landrace x Hampshire.
The results showed that the highest values of total heterosis were established for the crosses with participation of Duroc 11.03% and 13.88% respectively for the traits number of born alive and number of pigs on the 21st day.
The values characterizing the average heterosis are negative with the participation of the specialized sire breeds which is in conformity with their lower reproductive abilities.