Motility, acrosome integrity, membrane integrity and oocyte cleavage rate of sperm separated by swim-up or Percoll gradient method from frozen-thawed buffalo semen

Frozen-thawed semen of five buffalo bulls was used to compare efficacy of swim-up and Percoll gradient methods for separating viable spermatozoa. Sperm separated by the two methods were also tested to differentiate buffalo bulls on the basis of in vitro fertilization (IVF) rates. Recovery of motile sperm (%), increase in membrane integrity (%) and acrosome integrity (%) were compared after two sperm separation methods in experiment I, and in vitro fertilization rate (cleavage rate and cleavage index) was compared in experiment II. Swim-up separated sperm showed a higher motility (P < 0.05), while percent recovery of motile sperm was higher with Percoll separation (P < 0.05). Membrane integrity (%) of sperm separated with swim-up was significantly higher (P < 0.05) as compared to sperm separated with Percon gradient. Swim-up separated sperm gave a higher cleavage rate and cleavage index (P < 0.001). Sperm separated by swim-up showed significant difference among the bulls in cleavage rate and cleavage index (P < 0.05), while the Percoll gradient method did not. It has been concluded that separation of sperm from frozen-thawed buffalo semen by swim-up method can be more expedient for IVF in buffalo. (c) 2008 Elsevier B.V. All rights reserved.