LAUSR

This study was carried out to improve the kinetic motilities of frozen-thawed bull semen diluted with tris-based egg yolk diluent that was supplemented with Eurycoma longifolia jack aqueous extract. A total of 24 ejaculates were obtained from six cross-bred bulls using an electro-ejaculator. The extract of Eurycoma longifolia jack was distributed into three low doses and three high doses; cryopreserved samples were evaluated into three different times to confirm the results of kinetic motilities through different times and between groups. Path velocity (VAP μm/s), progress velocity (VSL μm/s), track speed (VCL μm/s), lateral amplitude (ALH μm/s), Beat Frequency (BCF Hz), straightness (STR %), linearity (LIN %), were evaluated three different times using Computer-assisted sperm analysis. Results revealed that the percentage of VAP, ASL and VCL were higher (p<0.05) in the frozen-thawed semen group supplemented with 5 mg mL-1 Eurycoma longifolia jack extract (73.19±1.91, 58.34±2.06 and 117.91±2.68 in first evaluation, then 74.22±2.06, 57.45±1.72 and 118.92±2.55 in second evaluation and 72.95±2.27, 56.75±1.30 and 119.07±3.54 in third evaluation; respectively). In conclusion, Eurycoma longifolia Jack aqueous extract supplementation to the semen diluent at 5 mg mL-1 significantly improved sperm kinetic motilities of frozen-thawed bull semen.