Ratio of gammas

hello,

gamma(a) works fine for a<173, but gamma(173) returns
[1] Inf
Warning message:
value out of range in 'gammafn' 

What I really need is the ratio

gamma(nu/2) / gamma((nu+1)/2)

is anyone aware of a way to re-express this in a form that pushes the
threshold past which a warning message is generated?

thanks!