A Preliminary Study on the Use of Betaine as a Cryoprotective Agent in Deep Freezing of Stallion Semen

Abstract

Summary In a preliminary experiment, betaine was added in concentrations ranging from 0 to 3.0 percent to stallion semen diluted with 4 % glycerol extender. Motility of frozen‐thawed semen was better in the extenders with high betaine concentration than in those of low concentration or the control. In a subsequent experiment, betaine was added to extended semen from five stallions to make a 2.5 % betaine concentration. Two different cooling rates were used. The effect of betaine on spermatozoal motility was positive at both cooling rates studied. Motility of frozen‐thawed 2.5 % betaine semen samples was significantly (p < 0.001) higher than that of the control samples. Zusammenfassung Vorläufige Untersuchungen zur Verwendung von Betain als cryoprotektives Agens beim Tiefgefrieren von Hengstsamen In einer vorläufigen Untersuchung wurde 0 bis 3 % Betain dem mit 4 % Glycerin enthaltenden Extender verdünnten Hengstsamen zugefügt. Die Spermienmotilität des tiefgefrorenen und wieder aufgetauten Samens war im Extender mit hoher Betainkonzentration besser als im Extender mit niedriger Betainkonzentration oder ohne Betain. In einem weiteren Experiment wurde Betain dem verdünnten Samen von 5 Hengsten zugefügt, bis eine Betain‐Konzentration von 2,5 % erreicht war. Dabei wurden zwei verschiedene Abkühlraten verwendet. Bei beiden Abkühlraten wirkte sich diese 2,5%ige Betain‐Konzentration im Vergleich zu Kontrollbedingungen positiv auf die Spermienmotilität aus (p < 0,001).

Choline Dehydrogenase Polymorphism rs12676 Is a Functional Variation and Is Associated with Changes in Human Sperm Cell Function

“…Preserving normal motility characteristics in sperm that have been frozen and thawed is an active area of research both in the fields of human andrology and veterinary animal husbandry. Kroskinen, et al [58] and Sanchez-Partida et al [59] reported increased sperm motility in thawed sperm when betaine was added to the cryopreservation media. It is hypothesized that betaine may directly interact with membrane lipids and proteins, altering the hydration status of these molecules, and thus protecting them through the freeze/thaw cycle [60].…”

Recent developments and concepts in the cryopreservation of spermatozoa and the assessment of their post-thawing function

“…Glycine betaine and proline were not additive, and were equally effective in the protection of ram spermatozoa against cryoinjury, but only in the presence of both glycerol and egg yolk (Sanchez-Partida et al 1992). The addition of glycine betaine was also shown to be cryoprotective for stallion spermatozoa; the percentage of motile spermatozoa was significantly higher after freezing and thawing in a standard diluent containing 2-3% glycine betaine compared with the standard lactose-egg yolk-glycerol diluent alone (Koskinen et al 1989).…”

Effect of Cryopreservation on Sperm Quality and Fertility

“…Egg yolk phospholipids can also lessen chilling injury on bull sperm by binding to low density lipoproteins of the membrane and by increasing the permeability of the membrane, although they do not alter intrinsic membrane composition and/or physical properties (Holt, 2000). The addition of concanavalin-A to the freezing diluent, a substance that has the ability to coat and thus protect spermatozoa membrane, has been suggested to provide additional protection for acrosome membranes and help to preserve motility post freezing and during thawing (Koskinen et al, 1989). The inclusion of liposomes, which have proved successful in bulls, has been tried with some success in equine semen (Heitland et al, 1995).…”