Distinct incubation for homologous in vitro spermatozoa binding on swine oocytes subjected to different storage conditions

AbstractThe sperm in vitro binding assay in homologous oocytes can be used to estimate the boar fertility potential, but its usefulness may be limited by laboratorial structure and oocytes availability. This study aimed at determining the effect of distinct methods of oocytes conditioning and incubation media for the in vitro penetration (IVP) test. Oocytes used in the IVP test were: fresh and conditioned in PBS (T1); cooled and conditioned in PBS at 5°C for 48h (T2); or stored in ovaries frozen at −20°C (T3). For each treatment, two incubation media were tested at 39°C for 6h: modified TRIS buffer medium (mTBM); or Beltsville Thawing Solution (BTS) extender. The responses of interest were: IVP and polyspermy rates; and the number of penetrating spermatozoa per oocyte. All responses observed with incubation in BTS were inferior to those observed with incubation in mTBM (P<0.0001). When incubation was done in mTBM, none of the responses differed across treatments (P>0.05). However, when incubation was in BTS, all the three responses were superior for T1 than for T2 and T3 (P<0.05). Thus, the IVP test may be conducted with ovaries either cooled or recovered from frozen ovaries with results similar to those observed with fresh oocytes, if incubation is done in mTBM

The effects of xanthan gum on equine sperm quality during cooling storage

ABSTRACT This study was designed to evaluate the possible benefits of adding xanthan gum to a standard extender for equine through in vitro analyzes of sperm quality. Semen was collected four times from five different stallions (n= 20 samples) and subjected to cooled storage under different conditions: control (only standard extender) and three different concentrations of xanthan gum (0.01%, 0.12%, and 0.25%) supplemented to the extenders. Sperm parameters, such as motility, mitochondrial functionality, and membrane, acrosome, and DNA integrity were measured after 0h, 24h, 48h, and 72h of sperm storage at 5ºC. Our observations indicated that sperm motility declined with longer cooling period with the 0.25% xanthan gum supplementation group compared with the control group. Other parameters, such as mitochondrial functionality and membrane and acrosome integrity also declined for all treatments during storage; however, no differences were observed between xanthan gum and control groups. DNA integrity did not significantly change during the storage. In conclusion, the addition of xanthan gum to equine semen extender is not harmful to the sperm structure, despite reducing the sperm motility