Sensational looking calf!!
How early can you tell if a bull calf is going to be a sire prospect?
I usually have a fairly good idea by the time they are 2 months old.
Or to put it another way can a brilliant looking calf grow out into an ordinary bull?
Yes, but the ordinary looking calf is much more likely to grow into an ordinary bull.
And vice versa a poor calf grow into an outstanding bull?
Why give him the chance? There was a reason he was a poor calf, either his dam didn't do him well, or he was proned to get infected by parasites or other illness, which ever way its an indication that his immune system wasn't as strong as some of his mates or he was compromised by the lack of quality of his dam. Bull prospects need to come out of outstanding cows who produce outstanding calves EVERY year. There is no point in keeping a bull intact out of an ordinary cow.
So I guess the crux of what I'm asking is at what age do you make the irreversible decision of who keeps their testes and who doesn't?
Some get castrated at birth, usually those with no eye pigment, high BW, or if the dam has poor mothering ability. The vast majority stay intact till weaning, then only the very best get to stay the rest goes with the commercial calves to the feedlot. Anyone who falls behind the rest after weaning or don't meet the minimum standards I set also gets culled.
Andrew