Reproductive period affects lipid composition and quality of fresh and stored spermatozoa in XXXX .

@entity5204 @entity844 @entity2627 @entity233 @entity1474 @entity1234 @entity1865
Semen of @entity233 between 31 and 52 weeks of age was analyzed to investigate the cause of reduction in @entity233 fertility at the end of the reproductive period. Sperm motility and viability, lipid concentration, @entity844 composition and lipid @entity2627 were evaluated on fresh spermatozoa or spermatozoa stored for 48h at 4 degrees C. Fertility of fresh semen was also evaluated. Fertility obtained with fresh semen decreased at 44-47 weeks of age. Ageing was also accompanied by a decrease in sperm viability (at 47 weeks) and later by a decrease in motility of spermatozoa (at 52 weeks). @entity1474 ( @entity5204 ) were the first lipids of fresh spermatozoa affected by age, especially n-3 and n-9 @entity5204 . Changes in these @entity5204 were followed by a 30% increase in lipid peroxidation at 47 and 52 weeks of age and a reduction in phospholipid content at 52 weeks. In vitro storage did not cause lipid peroxidation in sperm obtained during the first half of the reproductive period but @entity1234 ( @entity1865 ) levels significantly increased in sperm obtained during the second half of this period. In vitro storage also decreased phospholipid content of spermatozoa from 41 weeks of age, and viability and motility regardless of age. In conclusion, lipid alteration mainly originating from @entity5204 peroxidation could partly explain the decrease in semen quality and fertility observed with ageing. In addition, lipid peroxidation was increased during in vitro storage of spermatozoa from older @entity233 .
