Thirty six New Zealand White (NZW) rabbit bucks were divided into three experimental groups were used to assess effect of age and administration of vitamin E with selenium on some testicular traits, hematological and biochemical parameters. Group 1: young age (4-5 months), Group 2: middle age (9-10 months) and Group 3: old age (20-24 months). Each group was divided into two subgroups (treatment and control). Treated group was subcutaneously injected with vitamin E and selenium weekly for twelve weeks, while the other was given saline solution and served as control. Blood samples were collected at 6^th and 12^thweeks of experiment. Some hematological and biochemical parameters were determined in blood serum. At the end of experiment (12^thweeks), animals were slaughtered and the two testes and the epididymis of each buck were weighed.

The obtained results showed that hematological parameters were not significantly affected by age except for hemoglobin and white blood cells values. Vitamin E and selenium insignificantly increased red blood cells count, hemoglobin, packed cell volume and white blood cells count and decreased neutrophils (N), lymphocytes (L) and N/L ratio. Age had a significant effect on total protein, glucose and cholesterol. Vitamin E and selenium did not affect blood biochemical parameters. In addition, age of bucks had significant effects on body weight, testes weight and sperm output. Vitamin E and selenium had significant effects on total motile sperm per gram testis.
Generally, administration of vitamin E and selenium improved testes weight and sperm output. Middle age bucks were superior in most studied parameters than young and old age groups. Treatment of young group with vitamin E and selenium improved their total sperm output to comparable levels of that observed in control old and middle groups which could enhance their earlier usage in rabbit farms.