Correlations between seminal plasma enzyme activities and semen parameters in seminal fluid of Arabian horses

Document Type : Full paper (Original article)


1 Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Uludag University, 16059 Gorukle, Bursa, Turkey

2 Department of Biochemistry, Faculty of Veterinary Medicine, Uludag University, 16059 Gorukle, Bursa, Turkey


The objective of this study was to investigate aspartate-amino-transferase (AST), γ-glutamyl-transferase
(GGT), alkaline phosphatase (ALP), lactate-dehydrogenase (LDH) and acid phosphatase (AcP) activities and
semen parameters (volume, pH, concentration, total sperm number (TSN), progressive motility, dead sperm,
total morphological defect (TMD) and hypo-osmotic swelling test (HOST)) in seminal plasma of Arabian
horses. Furthermore, correlations between enzyme activities and semen parameters were examined. The
study was performed using seven healthy Arabian stallions of proven fertility, between 11 and 17 years of
age, from the Karacabey Stud Farm in Bursa, Turkey. Overall, 21 semen samples were collected from
stallions during the breeding season from March to May. A significant negative correlation was observed
between semen volume and concentration of TMD, AST, ALP (P<0.05) and LDH (P<0.01). pH showed a
significant correlation with live:dead ratio, GGT activity (P<0.05) and progressive motility (P<0.01). All
semen concentrations correlated significantly with TSN, TMD, ALP, AcP (P<0.01). Furthermore, significant
correlations were found between live:dead ratio and TSN, HOST (P<0.05); TSN and ALP, AcP (P<0.01);
progressive motility and HOST (P<0.01), GGT (P<0.001); AST and ALP, LDH, AcP (P<0.001); GGT and
LDH (P<0.05); ALP and LDH, AcP (P<0.01) and LDH and AcP (P<0.001). No significant correlation was
found between enzyme activities in stallion seminal plasma and semen parameters in different months,
except for pH and HOST.