Effect of lycopene supplementation on semen quality and reproductive performance in rabbit

<p>A total of 18 hybrid strain Martini male rabbits were randomly divided into three experimental groups. The animals in the first and second groups drank water with 0.1 and 0.5 g/l of lycopene addition (B and C groups, respectively), while water without any supplement was administered to the control group rabbits (A group) for 8 weeks. Semen was collected from 18 bucks (6 animals/group) for 5 consecutive weeks. Ejaculate volume was determined by graduated test tube and sperm concentration was calculated by Neubauer chamber. Sperm motility was evaluated subjectively by a phase contrast microscope and forward progressive motility (FPM) scored 1÷4 (low-high). Sperm viability was assessed by nigrosin/eosin (N/E) staining procedure. At the end of the semen evaluation period, 20 females per group were inseminated on day 11 <em>post partum</em> with a pool of semen collected from each experimental group. Data showed that the highest level of lycopene (C group) resulted in a significantly greater volume of ejaculate and total number of sperm than in the control group (0.98 <em>vs</em>. 0.78 ml and 364 <em>vs</em>. 227, P&lt;0.05), while sperm concentration was not affected. Lycopene addition did not significantly affect the sperm quality of fresh semen, but influenced the semen traits during storage (24h at 5°C). In particular, the motility, FPM and viability of the C group were significantly higher (P&lt;0.05) than those found in the A and B groups. No significant differences were found in reproductive performance (P&gt;0.05). This study shows the positive effects of lycopene supplementation on semen production and refrigerated semen characteristics. Lycopene supplementation of drinking water could have interesting applications in field conditions, although further research into the role of this antioxidant in animal production is needed.</p>