Abstract:
The quality of cryopreserved Boer goat semen may be influenced by the source and concentration
of energy supplements in the extender. The aim of the study was to improve the protocols for
cryopreservation of Boer goat spermatozoa using different disaccharides concentrations as
supplements in tris- egg yolk extender. Two experiments were carried out to investigate the effect
of (a) addition of three disaccharides (maltose, sucrose and trehalose) and (b) disaccharides
combination (maltose and trehalose) at different concentrations using tris-egg yolk extender. For
experiment 1: the study was replicated six times and was conducted in a 3 x 2 x 2 factorial
arrangement with three different sugars (sugars: maltose, sucrose and trehalose), two sugar
concentrations (0.12g and 0.22g) and two evaluation times (0 hours before cryopreservation and
120 hours after cryopreservation). For experiment 2: the study was replicated six times and was
conducted in a 2 x 2 factorial arrangement with two sugar concentrations (0.12g and 0.22g) and
two evaluation times (0 hours before cryopreservation and 120 hours after cryopreservation).
Semen ejaculates were collected at 7.00-9.00 am from three Boer goats twice per week. After
collection, the semen samples were pooled and diluted with tris-egg yolk extender at the ratio of
1:7 (semen to extender). Sperm quality (progressive motility, non- progressive motility, kinetic
motions, viability (live/dead) and morphology) were analyzed using computer aided sperm
analyzer (CASA). For experiment 1: sucrose 0.12g had higher progressive motility (PM %) when
compared to maltose, and trehalose at 0h but reduced after cryopreservation. Sucrose 0.12
showed high percentage of kinetic motions (straightness and average path velocity) when
compared to other sugars at 0 hours. More morphological defects M (CH) were revealed by
maltose 0.12 at 0 hours. Sugar type (ST) and evaluation time (ET) showed no significant
difference (P>0.05) in progressive motility (PM %), sperm kinetic motion, sperm viability and
morphology. For experiment 2: mixed/combined 0.12g (maltose and trehalose) revealed more
progressive motility (PM %) at 0h and reduced after cryopreservation. Table 6 and 9: of
experiment 1 and 2 showed an interaction caused by sugar concentration level and evaluation
time (L X ET) on the percentage of cut head M (CH%) and coiled M(C%) morphological
abnormalities. In conclusion addition of maltose 0.12g to the extender showed almost similar
results with that of trehalose at 0h and 120h. Therefore addition of maltose and trehalose to the
extender might improve the quality of Boer goat spermatozoa prior and post cryopreservation.
