Effect of soybean lecithin on freezability and fertilizing potentials of bovine spermatozoa

Abstract EN

Soybean lecithin has been attracted increasing attention and has been used to replace egg yolk in the semen extender.

In the present study, effect of soybean lecithin on bovine semen freezability and in vitro fertilizing potentials were evaluated.

Semen was cryopreserved in tris-based extender supplemented with different soybean lecithin concentrations (3, 5, 7, 10 and 20%) vs 20% egg yolk (control).

Semen post-thawing motility, viability and acrosomal integrity, DNA damage, enzymes leakage, total antioxidant activity (TAC), lipid peroxidation and in vitro fertilizing potentials were assessed.

Current results indicated that addition of 7% soybean lecithin to semen extender significantly (P<0.05) improved post-thawing motility, viability and acrosomal integrity (61.25±1.25%, 172.25±5.53 and 10.25±2.39 %, respectively) compared with control (47.50±4.78%, 106.25±16.88 and 22.00±1.47%, respectively).

At the same time, a significantly reduced (P<0.05) sperm DNA damage, tail length and tail moment of the cryopreserved semen (1.48±0.27%, 2.08±0.36 Bm and 3.14±1.32, respectively) compared with control (3.31±0.17%, 3.93±0.24 Bm and 13.09±1.38, respectively).

Moreover, extender containing 7% soybean lecithin significantly (P<0.05) increased TAC (0.47±0.04 mB/ml) and decreased lipid peroxidation (Malondialdehyde) of the cryopreserved spermatozoa (9.18±1.47nmol/ml) with respect to the control (0.19±0.02 mB/ml, and 21.57±1.45 nmol/ml, respectively).

Additionally, 7% soybean lecithin significantly (P<0.05) improved in vitro fertilization rate, cleavage rate, morula and blastocyst development (54.14±6.21, 52.81±3.32, 27.49±2.78 and 18.44±2.11%, respectively) compared with the control (35.10±3.23, 31.75±5.52, 12.2±4.08 and 4.82±2.12 %, respectively).

It was concluded that the addition of 7% soybean lecithin to the freezing extender improved freezability and enhanced in vitro fertilizing potentials of bovine spermatozoa through protection of DNA from deterioration and reduction of oxidative stress.