Effect of dietary flaxseed on semen characteristics and testosterone serum level of rabbit bucks

The aim of the present study was to evaluate the effects of 10%flaxseed on semen quality and testosterone serum level in rabbit bucks.For this purpose 40 New Zealand White male rabbits (150 days old)were divided in two homogenous groups submitted to the followingdietary treatments: control and LNA (supplemented with 10%extruded flaxseed and both the diets enriched with 200 mg/kga-tocopheryl acetate). After 2 months of dietary treatment semen andblood samples were collected weekly. Dietary flaxseed resulted in asubstantial rearrangement of sperm fatty acids composition. Indeed,the LNA group showed significant increase of LNA, DHA and n3/n6 ratio (p<0.05) along with a strong reduction of cholesterolcontent (170.9lg/106sperms; p<0.05) and consequently highphospholipids/cholesterol ratio (+0.8lmol/lmol; p<0.05). ThePUFA enrichment determined an increase of membrane fluidity, whilethe cholesterol reduction, mainly on acrosome, may permit sperma-tozoa to better undergo uterine stimuli and so to promote ovum-sperminteraction. Moreover, the control group showed lower values(p<0.05) regarding motility percentage (14.2%) and VCL (curvi-linear velocity) (59lm/s). Testosterone serum level was higher in theLNA group, probably due to the higher level of ligands in flaxseed. Inconclusion, this study shows that a dietary supplementation of 10%extruded flaxseed can improve some characteristics of rabbit sperma-tozoa by modifying the sperm lipid composition.