LAUSR

Abstract Zulu sheep is a Nguni breed indigenous to the KwaZulu-Natal (KZN) province of South Africa, and is reported to be under threat of extinction. Knowledge of factors that may cause the declining numbers is required for the planning of conservation programmes. We designed a study to evaluate the effect of ram age, season and geographic location on the quality of semen. The aim was to determine which rams are best for breeding and at which time of the year. A total of 192 rams were sampled for semen and blood in 8 different locations, three times each season. Semen was collected via electro-ejaculation into semen collection tubes while venous blood was collected from the jugular vein for testosterone and white blood cell (WBC) assay. Parameters used to assess semen quality were volume, pH, sperm concentration, progressive and mass motility, percentages of live and abnormal spermatozoa. The average semen volume and spermatozoa concentration per ejaculate were similar for autumn, winter and spring while being significantly different during summer (P