Influence of recovery methods and extenders on bull epididymal spermatozoa quality.

The aim of this study was to compare the effects of two extraction methods in combination with two different extenders in bull epididymal sperm collection. Testes from 23 sexually mature Limousine bulls were collected at the abattoir. Epididymal sperm recovery was performed using both the float-up (FL) and the retrograde flushing (RF) technique. Within extraction methods, half testes were processed with a Tris egg yolk extender and half with a Tris egg yolk-free extender. Sperm concentration, motility, viability and morphology were evaluated. Sperm concentration was not significantly different between methods. Flushing technique was significantly better than the FL method in terms of sperm quality, considering total motility (80.3 ± 2.3% vs 71.6 ± 2.0%, p < 0.001, respectively) and viability (84.5 ± 1.5% vs 77.2 ± 1.3%, p < 0.001, respectively). Egg yolk influenced positively motility and morphology in the FL method, whereas decreased viability in flushed samples. Results suggest the use of the RF technique to collect cattle epididymal sperm.