Seasonal variations in rete testis fluid secretion and sperm production in different breeds of ram

Production of spermatozoa and secretion of rete testis fluid (RTF) in rams was assessed by a rete testis cannulating technique. Four breeds (Ile-de-France, Romanov, Préalpes du Sud and cross-breed Romanov) were studied throughout the year. Inhibitory effects of the cannulation process on spermatogenesis were observed for some animals. Between-breed differences were found in sperm concentration and flow rate of the RTF. The seasonal variations in the daily sperm production of the testis were more pronounced for Ile-de-France rams than for the other breeds. There was a seasonal variation in the flow rate of RTF in Ile-de-France rams, the minimum flow being in February (winter) and the maximum in August-September (autumn).