Evaluation of enzyme activity in bovine semen.

The aim of this study was to investigate the activity of lactate-dehydrogenase (LDH), alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT), creatinine kinase (CK) and total protein in semen obtained from bulls during winter season. Five animals were included in the trial. Enzymes were assayed by using commercially available kits and expressed as UI/l (Spinreact, Spain) in fresh and frozen seminal plasma and sperm cells. In fresh semen LDH, GGT and CK showed higher activity (P<0.05) in sperm cells respect to seminal plasma (11978 vs 709, 7854 vs 2086 and 1161 vs 203, respectively). In frozen samples LDH was higher (P