Higher Number Of Spermatozoa Research Articles

Semen was collected over a 30-day period from 18 yearling beef bulls, nine Herefords and nine hybrids. Average age at the start of the test was 380 ± 20 days. A total of 112 attempted collections resulted in 94 samples. Fifty percent of ejaculates were considered acceptable for freezing from Herefords and 79% from hybrids, respectively. The hybrid bulls produced significantly more semen per ejaculate (3.3 vs. 2.2 ml), higher sperm concentration (1092 × 106 vs. 657 × 106 per ml), higher sperm numbers per ejaculate (3,834 × 106 vs. 1,499 × 106) and higher total motile sperm per ejaculate (1,999 × 106 vs. 669 × 106). Bull-within-breed variance was significant for semen volume, concentration, initial motility and progressive motility. Progressive motility was in favor of semen from the hybrid bulls but was not statistically significant (48% vs. 36%). It is suggested that the superiority of the hybrid bulls was related to earlier onset of puberty. The trial also suggests that useable semen for progeny test purposes can be obtained soon after bulls reach one year of age.

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