The objective of this work was to evaluate the in vitro effect of the addition of 1 mg pentoxifylline per ml of seminal samples from normospermic stallions, which were first diluted in Kenney extender and cooled at 5ºC. The evaluation was carried out using the following parameters: total and progressive motility rate, track speed, straightness and linearity rate, progressive velocity, viability rate and plasmatic membrane integrity rate. For this experiment, 20 ejaculates from four stallions were examined using Hamilton Thorn Research (Animal Version 12.0 L, EUA) with a Makler camera. The viability rates were obtained using eosin dyes under a light microscope and membrane integrity was obtained by fluorochrom, propidium iodine and carboxyfluorescein diacetat dyes under a fluorescence microscope. The semen examination occurred at 30, 60 and 120 minutes of incubation at 37º C, after 12, 24 and 48 hours of cooling at 5ºC. The pentoxifylline significantly increased the sperm parameter rates of motility and plasmatic membrane integrity for all incubation times, when compared with the control group. The rates were: +8.2% total motility, +4.7% progressive motility, +23.1 mm/s track speed, +7.4% progressive velocity, +4.7% viability and +3.5% plasma membrane integrity. The straightness and linearity rates were not significantly different between the control and treated groups. The experimental data confirm that pentoxifylline addition to stallion-cooled sperm, up to 48 hours after cooling, could preserve sperm quality for artificial insemination.
sperm; stallions; pentoxifylline; motility
