Nur Ducha - Biology Department, Faculty of Mathematics and Science, State University of Surabaya, Surabaya, East Java, Indonesia.
Dyah Hariani - Biology Department, Faculty of Mathematics and Science, State University of Surabaya, Surabaya, East Java, Indonesia.
Widowati Budijastuti - Biology Department, Faculty of Mathematics and Science, State University of Surabaya, Surabaya, East Java, Indonesia.
Trinil Susilawati - Reproduction Laboratory, Faculty of Animal Husbandry, Brawijaya University, Malang, East Java, Indonesia
Aulanni’am Aulanni’am - Biochemistry Laboratory, Faculty of Veterinary Medicine, Brawijaya University, Malang, East Java, Indonesia.
Sri Wahyuningsih - Reproduction Laboratory, Faculty of Animal Husbandry, Brawijaya University, Malang, East Java, Indonesia.

During storage at low temperatures, the spermatozoa quality changes due to cold shock and free radicals. Diluent supplementation with antioxidants is an effort to maintain the quality of spermatozoa during storage. This study aimed to evaluate the α-tocopherol effect in CEP extender on sperm quality, membrane integrity, and lipid peroxidation during storage at ۴°C-۵°C. This was a laboratory experiment that compared the use of ۲ mM of α-tocopherol in CEP with no addition of α-tocopherol (as control) in five bulls. Semen was collected from Brahman bulls, diluted in CEP with and without α-tocopherol, and stored at ۴°C-۵°C. Sperm motility and viability were investigated by a light microscope at a ×۴۰۰ magnification using Eosin-Nigrosin staining. Moreover, membrane integrity was evaluated by lipid peroxidation using the MDA assay and hypoosmotic swelling test. The sperm motility, viability, and membrane integrity were higher in CEP with α-tocopherol. Lipid peroxidation was significantly different between the treatment and control groups. The α-tocopherol supplementation in the diluent CEP could maintain the spermatozoa quality during storage at ۴°C-۵°C.

α-tocopherol, Brahman bull, Cauda epididymal plasma, Frozen, Spermatozoa