Quantitative semen characteristics of Malya and Boer bucks: Candidates for artificial insemination of goats in Tanzania

The objective of this study was to assess the quality of semen produced by two breeds of bucks, namely, Malya and Boer. A total of 90 ejaculates, 45 from each of six bucks comprising two breeds, Boer and Malya, were longitudinally collected for six months via artificial vaginas. Ejaculate collections were assessed for multiple parameters to assess semen quality and reproductive potential as related to performance. The assessment is based on a comparison of average scores between Boer and Malya bucks. These assessments incorporate variables such as the volume of ejaculate, the sperm concentration, and normal morphology, viability, and acrosome integrity. Furthermore, the integrity of sperm membranes and various velocity kinematics, such as straight-line velocity, average path velocity, and curvilinear velocity, and parameters such as lateral head amplitude, beat cross frequency, straightness and linearity metrics, were included. The findings revealed breed-specific differences in semen quality, providing significant detail for reproductive management techniques. Comparatively, Malya bucks were significantly (p<0.05) superior to Boer bucks in terms of volume, viability, normalcy, and kinetics, such as curvilinear velocity, beat cross frequency, straightness, linearity and velocity average pathway, whereas Boer bucks were statistically better in terms of straight-line velocity and beat cross frequency. No significant (p>0.5) breed differences were found in concentration, progressive motility, or membrane or acrosomal integrity. Compared with Boer bucks, Malya bucks presented outstanding semen quality values and are likely well adapted to the environment, making them more ideal for artificial insemination.