Effect of Different Concentrations of Chicken Low Density Lipoprotein on Quality of Frozen Buck Semen.

This study aimed to evaluate the effect of different concentrations of low density lipoprotein compared to egg yolk on quality of frozen buck semen. Four healthy mature Zaraibi bucks were used in this study. Semen samples were collected twice weekly using Electro-ejaculator. Semen samples with Progressive motility ( 80%), total abnormalities ( 10%) were pooled and diluted. Five extenders were used, Tris 2.5 % egg yolk extender with 5 ml glycerol as a control, and substitution of whole egg yolk with 4, 6, 8 and10% low density lipoprotein (LDL), respectively. Semen was diluted to 200x10^6 sperm /ml, and refrigerated (5°C) for three hours, prior to storage in liquid nitrogen (LN) for one week. Sperm progressive motility, life sperm, intact acrosome, plasma membrane integrity and abnormalities were assessed at post-thawing. The results revealed that the LDL extenders were more effective in preservation of progressive motility, intact acrosome and integrity of the plasma membrane of buck spermatozoa than whole egg yolk extender. Sperm progressive motility, intact acrosome and plasma membrane integrity were much higher (P 0.05) in the 8 % LDL extender (53.50, 54.64, 54.11) vs. (31.0, 26.31, 37.25) in the control 2.5% egg yolk. It was concluded that LDL 8% in extender improved the freezability of buck spermatozoa compared to other LDL concentrations and egg yolk.