Prof. Ahmed Abou Elsaoud Radwan :: Publications:

A total number of 30 bucks in three breed groups of rabbits named Gabali, V-line and Moshtohor line (M-line, as new synthetic line 50% Gabali and 50% V-line)), 10 bucks from each breed group were evaluated in project of synthesizing new rabbit line. Traits of ejaculate volume (EV), semen pH, mass motility (MM), sperm cell concentration (SC), individual motility (IM), live sperm per ejaculate (LS), and sperm abnormalities per ejaculate (SA) were studied. Significant differences for EV, SC, IM, MM, LS, and SA in Gabali, V-line and M-line were detected being 0.60, 0.66 and 0.72 ml for EV, 405.83, 474.48 and 456.1 x106 for SC, 46.95, 48.63, and 54.82% for IM, 2.26, 2.22 and 2.41 grads for MM, 80.63, 82.38, and 81.99% for LS, 11.79, 12.92, and 12.09% for SA, respectively. No significant differences for semen pH grad due to the effect of breed group. Significant differences for semen pH, EV, SC, IM, MM, LS, and SA in autumn, winter, spring and summer seasons were detected being 7.70, 7.74, 7.79 and 7.75 grad for semen pH, 0.67, 0.65, 0.68 and 0.45 ml for EV, 444.37, 447.72, 446.93 and 442.86 x106 for SC, 54.53, 57.09, 48.77, and 40.12% for IM, 2.57, 2.73, 2.16 and 1.74 grads for MM, 81.21, 83.24, 84.02 and 77.54% for LS, 11.66, 11.02, 11.48, and 14.92% for SA, respectively. The highest values in semen pH, EV, SC, IM, MM, LS, and SA detected to be semen pH (7.88) appeared during the summer with the M-line, 0.7 ml for EV appeared during the autumn with the V-line, 474.13 x106 for SC was recorded during the spring with the M-line, 58% for IM was recorded during the autumn with M-Line, 2.81 for MM was recorded during the winter with the Gabali, 87.47% for LS was recorded during the spring with V-line, 16.96% for SA was recorded during the summer with V-line, respectively. Gabali breed had superiority in SC and MM in winter, but V-line had superiority in EV and MM in autumn; SC and LS in spring; and MM in winter. However, M-line had superiority in MM and IM in autumn, semen pH and SC in spring and MM in winter. It could be concluded that the M-line, followed by V-line of buck rabbits could be used as effective indicators for good semen quality. Based on heterosis percentages, it is concluded that M-line bucks had superiority in EV (14.3%), semen pH (0.13%), SC (3.6%), MM (7.6%), IM (14.7%), LS (0.6%) and SA (-2.14%) over the two foundations, which might due to dominance and/or over-dominance genes action at different loci on chromosomes. Key Words: Rabbits, Gabali, Semen, sperm cell, dominance, over- dominance. Introduction Rabbit bucks are considered the basis of the reproductive success in the rabbit production especially when artificial insemination is performed as a routine in the rabbitry (Al-Sobayil and Khalil, 2002). Therefore, crossing between rabbit breeds may be required essentially to show heterotic effects on most economic productive and reproductive parameters. M-Line was founded in 2006 (Iraqi et al., 2010) as a synthesizing line between the Egyptian Sinai Gabali (50%), and the V-Line (50%), (Estany et al., 1989). The procedure of foundation began by mating V line does to Sinai Gabali bucks and it was followed by three generations of “inter se” mating. Afterwards the line has been selected to increase litter weight at weaning and individual weight at 56 day. Several methods have been used for routine analysis of mammalian semen, each describing specific quality criteria of the sperm. Semen analysis is the initial step in the evaluation of male reproductive performance. Standard semen analysis including sperm