1982vett":uc004aiu said:
Never. I let the bull do his work. He knows more about it than I do.
I only know what I've seen on our feedlot of around 4000 heifers of various ages. We use
bulls there and time-limited AI breeding. The breeder is limited by time in a particular pen,
if he hasn't gotten the job done in about a month he moves on to the next pen of
up-and-comers at the end of their VWP. We then leave the bulls to clean up after the
breeder. I can't tell you how many times I've seen heifers finally get pregnant 100 or more
days after the breeder left her to the bulls. If we pull the breeder out of that pen earlier
than usual then we end up with significantly more open heifers at preg check. This is a lot
of heifers just hanging around for an extra 100 days or more eating up feed - yes, it's
cheap feed: low-end hay, cull onions, blackened triticale. But still, a pregnant animal is
more valuable than an open animal the vast majority of the time (not always).
Cattle owners generally like their bulls, breeders and vets hate them. I'm neither
a breeder nor a vet so I'm not biased either way. But one breeder told me that if you
put 10 heat cows in a corral with 10 bulls, the bulls would waste their energy
competing for a single cow. I've seen a similar situation involving bulls. One day at
work I saw a small bull trying to mount a cow; when a large bull in the next pen saw
what was going on he gave a huge bellow and frightened the smaller bull right off
her back. And so there goes an opportunity for her to be bred which then decreases
our preg rate. It's not that the other bull even had a chance at it, they are just
very competitive animals and this caused problems for our breeding. They are great
at heat detection but they don't necessarily get the job done, and they can even prevent
the job from getting done.