Poultry spermatozoa are prone to oxidative damage and adversely affect their fertility. Bioactive constituents of citrus fruit confer antioxidant enrichment on its juice and are candidates to combat oxidative load in poultry semen. Computer-assisted semen analyser and oxidative status were used to evaluate the potency of two tropical citrus varieties (sweet orange and tangerine) as natural diluents for rooster semen. Fresh and ripe sweet orange and tangerine fruits were obtained and processed into juices using a standard protocol and included in dextrose saline at 0%, 10%, 20%, 30%, 40%, 50% and 60% as semen diluent. Semen pool from 30 breeder roosters of 35-40 weeks of age was allotted randomly in triplicates to the different fruit juice-dextrose at 1:2 dilution rate and evaluated for 5 h at room temperature. Diluted semen, according to treatments, was evaluated for sperm kinetics using a computer-assisted sperm analyser, and seminal plasma was assayed for lipid peroxidation and total antioxidant activity. The result obtained shows that tangerine and sweet orange juice inclusion significantly (p < 0.05) enhance progressive spermatozoa motility and semen kinetics compared favourably with undiluted semen. The diluents had a proportionate increase in antioxidant activity with juice inclusion at 0 h and the antioxidant activity of 40%, 50% and 60% fruit juice-based diluents was higher than undiluted semen at 5 h. There was a reduced lipid peroxidation in juice inclusive diluents and increase lipid peroxidation rate in undiluted semen and 0% juice inclusion. In conclusion, tangerine and sweet orange juice inhibit lipid peroxidation in rooster semen and enhance progressive spermatozoa motility and maintain rooster semen kinetics.
Keywords: Antioxidants; Diluent; Lipid peroxide; Sperm motility; Sweet orange; Tangerine.