Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be
therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and
whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight,
testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was
cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone
concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring
(p<0.001). No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks,
or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm
variables were lower during the winter period (at least p<0.05). After freezing-thawing, the quality of winter-collected sperm was
better, in some respects, than that of summer-collected sperm (at least p<0.05). These results reveal that Blanca Andaluza bucks
show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour
between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during
winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer.