Morphological analysis of boar spermatozoa by age and breed

The total of 56 boars from 12 farm units (3 to 7 boars per farm) were used for cytological and morphological examination of semen.
Large White (LW, n = 18); Swedish Landrace (SL, n = 11), Duroc (OA, n = 12); German Landrace (NL, n = 6), crossbreeds (OST, n = 9) boars were used for examination. Sperm was stained with eosin/nigrosine in one step. According to the findings of spermatozoa with protoplasmic droplets (PPD), boars were divided into groups with ≤ 10% of the PPD and the group with > 10% of the PPD. The impact of the PPD rate to number of live born piglets per litter and correlation of PPD rate and findings of live sperm with intact
akcrosoma (LIA), or normal apical ridge (NAR) were investigated. Farrowin rate and abnormal sperm with tail deformities was significantly (p <0.05) lower in the boars younger than two years, compared to the boars older than two years (farrowing rate: 74.32% vs. 62.82%). Statistically significant correlations were found between the findings of protoplasmatic droplets (PPD)
on the tail of spermatozoa in native semen and number of live born piglets per litter (r = 0.44, p = 0.001). The medium correlation within these parameters were found in the Large White (r = - 0.57, p <0.05, n = 18), and Duroc boars (r = 0.68, p <0.05, n = 12). Other boar breds did not have significant correlation. The finding of cytoplasmic droplets on boar sperm tail is very stable and relatively easy to establish. It should be used as a practical mathod for control the quality of sperm as a selection parameter.