Semen production performance of Sahiwal bulls

Abstract

Semen characteristics of Sahiwal bulls (5 young; &lt 3 years and 2 adults; &gt3 years) and effects of age and seasons (summer, rainy and winter) on semen production performance were investigated. Overall mean values of semen volume (ml), concentration (million/ml), mass activity (0-5 scale), initial motility (%), live sperm (%), head abnormality (%), mid piece abnormality (%), abnormal tail (%) and total abnormal sperm% were 3.15±0.13, 1335.25±51.00, 2.66±0.07. 52.71±1.31, 70.40±3.91, 4.50h±1.37, 6.80±1.82, 7.10±1.26 and 18.40±3.03 respectively. Effects of age on semen characteristics and frozen semen doses production of Sahiwal bulls were significant. In adult bulls, the semen volume, mass activity, initial motility and post-thaw motility was 125.37, 10.63,28.77 and 12.86% higher as compared to young bulls. Number of frozen semen doses produced per ejaculate were 61.90% higher in adults as compared to young bulls. Effect of seasons was significant both on semen quality and production performance. Initial and post-thaw motility were highest during winter (60.28±3.58 and 49.64±2.06% respectively) and lowest during rainy (49.03±2.56 and 37.97±2.56% respectively) seasons. During winter average number of frozen semen doses produced per ejaculate were 47.79 and 96.30% higher as compared to summer and rainy season respectively. Effect of age on rejection rate of ejaculates was significant. On overall basis 77.16% ejaculates in Sahiwal bulls were rejected from frozen semen doses production. In young and adult bulls 9.26 and 39.32% ejaculates, respectively, were frozen successfully (having post-thaw motility =50%).Effects of seasons on rejection rates were significant. It was the highest during rainy season (83.33%), followed by summer (76.79%)and winter (42.86%). The best period for harvesting of semen doses from Sahiwal bulls was winter followed by summer. For obtaining large number of doses mature (&gt 3 years) Sahiwal bulls might be preferred over young bulls.