Effect of photoperiod on semen production and quality in bucks of Verata and Malagueña breeds

Abstract

A group of 19 bucks of two Spanish breeds from different latitudes (Verata 40 °N, n = 10, and Malagueña 37 °N, n = 9) were used to study the effect of photoperiod on semen characteristics (volume, concentration, number of total sperm per ejaculation, motility percentage, percentage of normal acrosomes and percentage of abnormal forms). Semen samples were collected once a week with an artificial vagina, when the bucks were between 12 and, 23 months of age, and analyzed immediately after collection. There were differences between breeds in semen characteristics, with higher semen production and better semen quality ( P < 0.01) observed in Malagueña bucks. An influence of photoperiod ( P < 0.01) on both semen production and quality was observed in the Verata breed, with a noticeable improvement in almost all semen characteristics during the decreasing photoperiod. However, Malagueña bucks were less affected by photoperiod and had more uniform semen production and quality throughout the year. Differences were observed between bucks of both breeds with regard to semen production ( P < 0.01), but only in Malagueña bucks with regard to semen quality ( P < 0.05). The absence of a buck X photoperiod interaction in both breeds showed that semen characteristics affected by photoperiod changed in the same way in all the bucks throughout the year. The low influence of photoperiod on semen production and quality of Malagueña bucks allows us to use them as breeders in any season of the year. However, it is advisable to control the use of Verata bucks as breeders during winter and spring due to the influence of the increasing photoperiod on semen production and quality of these males.