I just received 60 +3 extras on Friday. Not new to raising chicks, hatches lots of my own, but this time was my first purchase from a hatchery(privetts). I got them mid Friday, started them on the vitamin electrolyte water and food in my brooder. The problem is since Saturday, I've lost 8. Is this high or how it goes with shipping birds? Are cornish cross birds more sensitive? Any input would be helpful!