Pregnancy rate

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If you have a defined breeding season, say 60-90 days, you should expect at least 90% of your cows to be bred. Herds with good fertility will be above that. My replacement heifers this year were 100% with a 75 day breeding season. I had 1 open cow out of 36, so my preg rate was 97.2%. I didn't preg the ones on my cull list, and I am pretty sure 1 or 2 of them would have been open. My opinion is, you need to be at least at 90%, and 95%+ for a good, fertile herd.
I like them to drop in the late summer to the end of fall. With 517 heifers were split in to the early and late breeders. For the 08 calving 4 were not pregnant, 3 still born, and 8 sets of twins. We had 518 drop for 138 days this year.

We put 40 cows to a bull and rotate the bulls every 10 days. So every bull works 10 days on 10 days off. After 60 days then we run all the early breeders back together with a clean up bull for 20 days. We start the late breeders the next day the same way.

As there born we log there birth dates in to the computer to determine if there going to be in the early or late group the next year. Fall of 09 will have 564 calving out of 566. Next year is an AI year so we will have a pop of 75 AI cows + the normal ones at the same time.
Mine has been running about 93%. But the thing that I noticed is that at 90% bred rate and 10% cull it looks like over 10 years the whole herd would have been culled. Is this correct?
i think it would probably depend on a variety of factors (age and condition of females, type of breeding) for your situation
i have a varying age group so older cows slow down and fall out and are replaced.on one place we did spring cows had a 80% preg rate which is low. but i tighted up the breeding season by pulling the bull 30 days earlier(we bought them 2 years ago and they calved year round) and some of the late calvers didn't make it.
open cows were: 3 late calvers (sale barn called one 1st period), 1 old cow, 2 first calf heifers(moved to the fall group).
I too have heard 90%.
Reminds me of the year that we decided to really cut down our commercial herd to make room for more purebreds. We had gotten rid of a few the year before but we decided we would only keep the very best. So we put the bull in for one heat month only and decided to ship anyone who didn't catch. All of them came up pregnant.
This is a very confusing question, since the questioner asked about pregnancy rate
and every response referred to conception rate. I researched the question anyway
and came up with various answers such as "way below 25% per year" in the southern part
of the US. However, a 25%-30% preg rate is considered optimal at any given time over
a 21-day heat cycle for a given cohort. In the hotter parts of the US, conception rates,
and of course preg rates, are likely to be lower than in cooler parts.

The difference between preg rate and conception rate is this:

Conception rate is the number of cows found pregnant divided by the number of cows bred.
Preg rate is the number of cows found pregnant divided by the number eligible to be bred
over a 21 day heat cycle. Bred-eligible includes anaestrous cows even though they aren't
likely to be bred and won't "take" even if, as commonly occurs, they are raped numerous
times by a bull.

Increasing your preg rate is useful for shortening calving intervals and thus enhancing
reproductive success over a shorter period of time. Conception rate hasn't been
considered an important number for at least 6 or 7 years, I see it mostly being used
to measure the success of a particular AI breeder. Unfortunately, that number only depends
on how picky the breeder is. If he selects only the obvious standing heats to be bred,
then his conception rate will make him look really good. However, if he allows other,
"silent heat" and ambiguous heat cows to pass by the opportunity to be bred, then overall
preg rate will be lower as a result. So it seems that the more "successful" a breeder *appears*
at getting cows pregnant the less successful it is for the cattle operation as a whole,
since conception rate only considers cows that he bred and not the ones that he walked
past either on purpose (that one didn't *look* ready) or by mistake (oops!).
RonE, I expect all my cows to conceive and be pregnant at their appointed time. Don't care what you call it. ;-) If they don't, they become part of the cull factor.
at our place we typically have 1 unbred cow a year, out of about 18 cows and 3 heifers, so about 95%... we'd like better, if it could be 1 out of 40, we'd be happy with that, but a lot of the time we know ahead of time the cow is no good anymore.

just because you replace 10% of the herd per year does not mean that you don't have older cows, it can mean that your old cows are good, because you weed out the bad ones early on... we typically save 3 heifer calves a year, which would work out to about 15%.. we also breed at 2 years old, but there's a good chance one of the three will end up in the freezer when she's a long yearling because she didn't keep up to the others.. also, we found that if a cow is going to have trouble, it's either when she's young (not being bred for the 2nd calf, or late) or when she's old and tired out. We are also less and less tolerant of attitude problems.. you break fences, you're gone, you're a witch at calving time, ditto, your nice roan colour as a calf has turned to mouse-grey and you look like a dirty rag.. well, you better walk the line...

Yes, keeping heifers 2 years is definitely a loss when they don't perform, but we never need to pull calves anymore and they have a lot more milk... meanwhile they can eat the old hay that we wouldn't want to feed to the pregnant cows, so they aren't useless... we just have to put up with their mooing since they're always in heat
1982vett":9ltim5bb said:
RonE, I expect all my cows to conceive and be pregnant at their appointed time. Don't care what you call it. ;-) If they don't, they become part of the cull factor.

Have you ever tried CIDRs as a reproductive strategy with those difficult cases?
1982vett":uc004aiu said:
Never. I let the bull do his work. He knows more about it than I do. :p

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.

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