Young bird losses

Why are so many birds being lost on good days.Most lofts between 30 to 50 percent missing .I sent51 birds at 1045 yesterday had 27 back since then 8birds back .From 1oclock not a bird back till 8oclock lat night Well trained 3transporters why?
Spoke to members of Up north Combine lofts they had a worse race than us.Do we need to look at changing when we race.
One idea basket early Saturday morning travel to race point on the morning possibly race after 3saturday for the likes of Wakefield . What do you think it needs to be looked at any ideas to be put forward for discussion.