Abstract:
Ram seminal plasma increases the fertility of frozen–thawed ram spermatozoa deposited
into the cervix. The aim of the current study was to compare the effect of ram seminal
plasma to that of bull seminal plasma, dog prostatic fluid, protein-free TALP, TrilEq (Triladyl
with 0.5 m of Equex STM paste added to each 100 m ) and heat-treated skim milk on
longevity and percentages of progressively motile and aberrantly motile frozen–thawed
ram spermatozoa. Three ejaculates from each of 6 rams were extended in TrilEq, pooled and
frozen in straws as a single batch per ram. One hundred and eight straws (3 straws from
each ram for each fluid) were thawed in random order. Once thawed, a straw was emptied
into a tube with 0.85m of the appropriate fluid at 37 °C and kept at that temperature for 6 h.
Motility was assessed at ×200 magnification immediately (time zero) and 2, 4 and 6 h after
thawing. Progressive motility decreased from each time to the next (P < 0.05) and was
39.0%(0 h), 26.0%(2 h), 19.6%(4 h) and 12.6%(6 h);SEM1.24, n=108 for each group.Ram
seminal plasma resulted in higher progressive motility than bull seminal plasma, lower
than milk, and similar to the other fluids. Ram seminal plasma resulted in lower aberrant
motility than protein-free TALP and similar aberrant motility to other fluids. The effect of
ram seminal plasma and dog prostatic fluid was very similar. The effect of ram seminal
plasma on the fertility of frozen–thawed ram spermatozoa deposited into the cervix is not
due an exceptionally beneficial effect on the motility of spermatozoa.
