Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 2/25/2008
Publication Date: 7/7/2008
Citation: Freking, B.A., Purdy, P.H., Welsh, C.S., Spiller, S.F., Blackburn, H.D. 2008. Boar fertility and semen quality characteristics in lines of pigs selected for component traits of female reproduction [abstract]. Journal of Animal Science Supplement. 86(E-Suppl. 2):208-209. Abstract #W50.
Technical Abstract: Selection for 11 generations for ovulation rate (OR) or uterine capacity (UC) resulted in significant changes in component traits of litter size. Our objective was to characterize male fertility as a correlated response to selection compared to an unselected control line (CO). Each boar (n=60) from two replicate seasons was collected twice. The sperm-rich fraction was obtained and volume and concentration of sperm cells was measured to estimate total sperm production. Each ejaculate was extended 1:3 v/v with Androhep Plus (Minitube, Verona, WI) and packed for shipping to the NAGP lab for processing into frozen straws. Semen quality was measured by computer assisted semen analysis at three time points: fresh (F), 24 h after extender added (E), and post-thaw (PT). A mixed model analysis of variance was applied to the data. Fixed effects of replicate, line and two-way interactions were fitted. The random effect of boar within line x replicate was used to test line differences. Sperm concentration was not different (P = 0.18) among the lines (0.594, 0.691, and 0.676 *10**9 cells/ml) for CO, OR, UC lines, respectively. Significance (P < 0.05) was detected for volume of the sperm-rich fraction, greatest for OR (86.4 ml), intermediate for UC (75.6 ml), and lowest for CO (70.2 ml). Line differences were thus detected (P < 0.02) for total sperm production, greatest for OR (54.9 *10**9), intermediate for UC (48.7 *10**9) and lowest for CO (40.5 *10**9). A higher percentage of progressively motile sperm and also higher estimates of sperm velocity only at time point E (P < 0.01) were detected in favor of CO. Estimates of motility, velocity, and activity measured on F and E time points were moderately and positively correlated with estimates obtained PT. Selection for component traits of female reproduction has had a favorable effect on total sperm production of boars.