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Relationship between andrologic profile and semen freezing in two-year-old Nelore bulls, pre select by breeding soundness evaluation (BSE)

Andrologic (n=163) and semen freezing (n=55) parameters from young Nelore bulls were evaluated for two consecutive years, as well as their associations searching for andrologic markers for high fertility and semen freezing. Differences in andrologic profiles (P<0.05) between years were registered, reflecting the success of semen freezing, even after andrologic selection. Percentages of 26.6 and 19.5 of discharged ejaculates, pre and post-freezing, respectively, were recorded, due to physical semen parameters. Overall sperm motility, vigor, and viability means were, respectively, 66.4±5.7%, 4.8±0.4, and 76.3±8.5% pre-freezing; and 29.4±8.5%, 4.6±0.6, and 34.5±11.1% post-freezing. The post-freezing recovery mean was 44.5±13.4%. Significant correlations (P<0.05) between body weight and pre-freezing sperm motility (0.43) and post-freezing sperm recovery standard (-0.50) were estimated. Correlations were also observed (P<0.05) between volume of ejaculate and age (0.50), sperm motility (0.28), total sperm defects (-0.32), and post-freezing sperm recovery standard (-0.37). The correlation between sperm concentration and post-freezing sperm recovery standard was 0.42. Significant correlations (P<0.05) between testes shape and scrotal circumference (0.58), and total sperm defects (0.33) and vesicular gland area (0.43) were also observed.

bulls; Nelore; semen; andrology; cryopreservation

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