Lipid peroxidation in avian semen

The main cause of sperm chromatin damage is oxidative stress related to embryo development failure and adult infertility in mammals and also avian. Oxidative stress results in lipid peroxidation (LPO) causing cell damage. Lipid peroxidation is the oxidation of polyunsaturated fatty acids (PUFAs) in biological systems and causes changes in the physical structure and characteristics of the cell membrane. Due to the high amounts of PUFAs in the avian sperm membrane, its sperm seem susceptible to pe-roxidative damage and is a substantial factor in the fertilization capacity of sperm. The most commonly used methods for measuring LPO or its by-products, such as malondialdehyde (MDA) and 4-hydroksy-2-nonenal (4-HNE), in bird semen are based on the colorimetric method TBARS (thiobarbituric acid reactive substances) and on the use of a fluorescence probe (CC 11-BODIPY 581/591) as a marker to evaluate membrane lipid peroxidation. This review aims first to introduce LPO in avian semen and its effects on avian sperm and second to summarize the commonly applied methods of evaluating LPO and its damage in fresh and stored avian semen.