REPRODUCTIVE PERFORMANCE OF FRIESIAN BULLS DMINISTRATED WITH SELENOMETHIONINE, ZINCMETHIONINE OR THEIR OMBINATION

his investigation was to estimate the impact of daily oral treatments with some organic antioxidants as selenomethionine (Se-M) and zincmethionine (Zn-M), separately or together (Se-M plus Zn-M) to Fresian bulls through 150 days upon some blood components, libido, characteristics of fresh semen and frozen-semen thawed at various thawing regimes, as well as, fertilizing ability of bulls spermatozoa. Sixteen healthy Friesian bulls were separated into 4 groups. Bulls in the first, second, third and fourth groups were fed a basal diet, and given oral dose of 0, 0.3 mg Se-M, 4mg Zn-M, and 0.15mg Se-M plus 2mg Zn-M/kg of DM/bull/daily, respectively, for 150 days. The results elucidated that bulls were given Se-M plus Zn-M had optimal (P<0.01) values of hematological aspects, differential of leukocytic count, blood plasma testosterone, seminal plasma initial fructose, libido, as well as, physical aspects of fresh semen and frozen-semen thawed at various thawing rates comparing with the control or other treated bulls. Frozen-semen thawed at 55ºC for 15 seconds (rapid thawing rate) had best (P<0.01) quality, freezability and some biochemical components of seminal plasma and fertilizing ability of spermatozoa. In conclusion, daily oral dose of 0.15mg Se-M plus 2mg Zn-M/Kg DM/bull, as organic antioxidants through 150 days, could be suitable treatment for Friesian bulls, to achieving optimal quality of fresh semen production and freezability of semen, as well as, fertility of bulls spermatozoa, especially when frozen-semen thawed at 55º C for 15 seconds.