What are the chances of giving my partner genital herpes if we use protection and i'm on daily suppressive therapy of valtrex (valacyclovir) and i have no symptoms ?

50%: Two variables are at play here. If you have no symptoms you do not know where you are infected and thus condoms only protect him if the infection is where his covered penis comes in contact with you. Second suppressive therapy only suppresses viral shedding by 30 to 50%.

It's still possible: The CDC says the only way to avoid STDs is to not have vaginal, anal, or oral sex. Outbreaks can occur in areas that are not covered by a condom so condoms may not fully protect you from getting herpes. Also, Valtrex (valacyclovir) does not prevent the spread of genital herpes. Herpes infections are contagious and it is possible to infect other people even while you are taking with Valtrex (valacyclovir).