The aim of this study was to determine the synergistic effects of centrifuged egg yolk (EY) and soybean lecithin on post-thaw Caspian horse semen motility, morphological abnormalities, and assessment of membrane integrity.
Houshang Nouri MSc a , Armin Towhidi PhD b , Mahdi Zhandi PhD b , Raheleh Sadeghi MSc a
a Department of Animal Science, College of Agriculture and Natural Resources, University of Tehran, Karaj, Alborz, Iran
b Department of Animal Science, Faculty of Agricultural Science and Engineering, College of Agriculture and Natural Resources, University of Tehran,
Karaj, Alborz, Iran
E-mail address: houshang.nouri@alumni.ut.ac.ir
Journal of Equine Veterinary Science
Abstract
The aim of this study was to determine the synergistic effects of centrifuged egg yolk (EY) and soybean lecithin on post-thaw Caspian horse sperm motility, morphological abnormalities, and assessment of membrane integrity.
The centrifuged EY (CEY) was added at concentrations of 2% and 4% to a defined INRA plus 1.25% soybean lecithin extender used to freeze Caspian horse semen. In this experiment, ejaculates collected
from each Caspian horse (n ¼ 4) were divided into three equal aliquots and diluted in CEY 2% (INRA2), 4% (INRA4) supplemented, and without any CEY (INRA0) in INRA plus 1.25% soybean lecithin extender, respectively. Thereafter, samples were frozen and thawed following a standard protocol.
Sperm cryosurvival was evaluated in vitro by microscopy assessments of post-thaw sperm motility (by means of computer-assisted semen motility analysis [CASA]), acrosomal and other abnormalities (head, mid-pieces, and tail) and plasma membrane integrity (evaluated by HOST).
In Caspian stallion, semen extended with INRA2 had significantly higher CASA motility and CASA progressive motility than those extended with the rest of extenders after freezing and thawing (P < .001).
There was no significant difference in path velocity (VAP), VCL, and ALH among three groups (P > .05). For straight line velocity (P < .01) and LIN (P < .001), the highest values were obtained from the INRA4 group.
The highest percentages of acrosomal and other abnormalities were found in semen diluted in INRA4 (P < .001). In the group frozen INRA2, the percentage of membrane integrity was significantly higher than that of the other groups (P < .001).
The use of CEY 2% in combination with soybean lecithin significantly improved Caspian horse semen freezability.
Keywords: Miniature Caspian horse , Centrifuged egg yolk, Soybean lecithin ,Cryopreservation ,Sperm