Evaluation of the effects of different trypsin treatments on semen quality after BHV-1 inactivation, and a comparison of the results before and after freezing, assessed by a computer image analyzer.
Semen infected experimentally with infectious bovine rhinotracheitis virus (BHV-1) was treated with trypsin at concentrations of 0.30%, 0.25% and 0.15%, with or without (w or w/o) trypsin inhibitor in order to render the semen virus free. The trypsin treatments (at 0.30% and 0.25% by concentration) inactivating the virus up to 10(4) TCID50/ml, and its effects on semen quality were assessed weekly from the 1st to 20th week after being frozen. The following parameters were determined using a computerized semen analysis system (Hamilton Thorn motility analyzer, HTM): total motility, progressive motility and linearity of sperm cells. The results showed that the total and progressive motility of sperm cells were reduced in frozen/thawed semen, principally in the semen treated with trypsin at concentrations of 0.30%. Moreover, the plasma membranes were damaged by trypsin treatments (0.30% by concentration), as determined by the hypoosmotic swelling test (HOS test). These findings suggest that trypsin treatments were effective against the virus however the effects on semen quality and the possibility of a decrease in semen fertility were clear. Trypsin treatment could be recommended at a maximum concentration of 0.25% (w/o trypsin inhibitor) on semen with a high concentration and high motility values of spermatozoa before freezing.
Silva
N
N
Veterinary School, UFMG, Department of Preventive Veterinary Medicine, Belo Horizonte, Brazil. nivsilva@dedalus.lcc.ufmg.br
Solana
A
A
Castro
J M
JM
D000818:Animals; D002417:Cattle; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D007242:Herpesvirus 1, Bovine / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D008297:Male; D012661:Semen / Q000187:drug effects / Q000502:physiology* / Q000821:virology; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D012984:Software; D013081:Sperm Motility / Q000187:drug effects; D014357:Trypsin / Q000494:pharmacology*; D017735:Virus Latency
D014357:Trypsin