Using Weather Radar turned on in order to avoid a bird strike ??? No way, I repeat, NO WAY !!! The weather radar beam strength is so low and so thin, the same width of a pen, that I can say that it's IMPOSSIBLE.
During takeoff in a clear day you just need the Predictive Windshear feature working fine and to turn it on you need the Thrust Levers beyond 53 degrees of TLA and that's all, I mean in the B-737NG.
Cheers