Effect of genetic group, semen diluents and freezing regimens on sperm freezability and goats reproductivity

Abstract EN

Two experiments were designed to study the effect of bucks breeds, semen extenders and freezing regimens on post-thaw semen motility and viability index (experiment 1).

In experiment 2, semen diluents effects on reproductive performance was conducted.

Semen was collected from Aradi (A), Damascuss (D) and cross (½A½D) bucks breeds.

Good quality semen was divided into 4 portions, each diluted with one diluent (Milk, Na.

Citrate, Tris and Na.

Bicarbonate).

The diluted semen was packaged into 0.5 ml straws then cooled to 5C.

After equilibration, half of the packaged straws were suspended 15 cm above liquid nitrogen (LN) for 15 min.

(Freezing regimen1; slow).

Other half of straws was suspended at height 15 and 5 cm of LN for 10 and 5 min, respectively (Freezing regimen2; rapid) before plunged into LN.

Frozen semen was thawed for post-thaw motility and viability.

In the second experiment, semen with good quality was extended with three types of extenders (Milk, Na.

Citrate and Tris).

Diluted semen were cooled to 5C and used for AI.

Results revealed that, pre-freeze semen motility was significant higher in Tris, Na.

Citrate and Na.

Bicarbonate than milk diluent.

Post-thaw semen motility and viability were highly significant for milk and Na.

Citrate than Tris and Na.

Bicarbonate diluents.

Post-thaw semen motility was significantly higher in Aradi and Damascus than crossbred.

Post-thaw semen motility and viability revealed, significant higher means for Freezing regimen 2 than regimen 1.

Milk and Tris diluents were significantly higher than Na.

Citrate for fertility, fecundity and prolificacy.

Aradi does was higher than Damascus does in fertility, fecundity and prolificacy.

Also, Aradi does was significantly higher than ½A½D does in fertility, while the reverse trend was observed in fecundity and prolificacy.

It was concluded that, regarding to post-thaw semen motility, semen viability, fertility%, fecundity% and prolificacy%, milk diluent is preferable than Tris and Na.

citrate.

Fertility rate of Aradi goat breed is higher than Damascus and crossbred (½A½D).