Early Heifer Maturity ?

[Stocker Steve]

We are refining on an approach where we bred retained heifers a month before the cow herd. Thus these sim-angus heifers are 13 to 15 months old, 700 to 850#, when their breeding season starts.

What percent would you expect to be sexually mature at this point,
and would there be an advantage to syncing them all for the first round of breeding?

 

[MtnCows93]

im no expert but i wont ever wait till there older than 13 to 15 months, i shoot for 12 to 14 and sell the late breeders

 

[Nesikep]

I'd like to see them a bit heavier, especially considering the Sim influence.. but they should all be cycling anyhow.. I breed at 14 months and never have an issue

 

[NEFarmwife]

We breed our heifers prior to cows. They are generally 12-13 months. We sync their heats and mass breed. We have a really good success rate.

Our first will hit the ground around Christmas. Then we cycle thru cows calving. Anything that hasn't calved by March 1st, gets sold. We keep a tight calving window.

 

[NEFarmwife]

We also did our set of Montana heifers that were 750lbs (some of ours wean at that!) and our success rate wasn't as good. They did breed but out of 120 heifers, we only had 70 that stuck to AI. Had another 20ish that got stuck the next cycle (bulls), and the rest a cycle or two later.

We were apprehensive in breeding at those weights and they were plenty old enough to breed.

 

[Stocker Steve]

We also did our set of Montana heifers that were 750lbs (some of ours wean at that!) and our success rate wasn't as good. They did breed but out of 120 heifers, we only had 70 that stuck to AI. Had another 20ish that got stuck the next cycle (bulls), and the rest a cycle or two later.

Are you breeding them on the same day, or on observed heat?

 

[elkwc]

We tried breeding younger. Have went to 14-17 months of age. The variation is because until this year the bulls were left in year round. Our goal in the future will be to calve them at 24-27 months of age. We have had less issues by letting the heifers mature a little more and calving later than we did calving at 20-23 months of age.

 

[Coosh71]

We run some Gelbvieh over Angus/Angus Hereford and Char cross cows. We have seen some not all, heifers start cycling at 7+ months. We do not breed at that age, but they are cycling. By 12-13 months our heifers are 750+ and we have no reservations putting our LBW RA bull on them. We do synch them to try to tighten the calving window. Last year we put a bull on 20 heifers at 12-14 months old and got 100% bred in 60 days. We like the Gelbvieh influence on our heifers fertility so far. This year we will do the same with 18-20 heifers that we like.

 

[Coosh71]

On a side not we did keep 12 of the 20 heifers last year after calving and they all are in the top 1/2 that bred back this year, and as first calf heifers some of their heifers will be retained this fall for possible replacements next year.

 

[T & B farms]

I agree with the gelbvieh comment. I think some of them come out of the womb cycling. I have saw several of my 5-7 month old gelbvieh heifers standing for the bull. I don't really like that, but knock on wood haven't had one hurt. Everything gets a shot of lute at weaning.
I have heard of simi being early maturing, but no personal experience.
I pelvic measure and track score everything a couple weeks prior to breeding and that has cut way back on my opens.

 

[Nesikep]

For me, I've never had a problem with the first timers breeding back.. in fact I found they breed back easier if they're exposed to the bull shortly after calving, I find milking for a long time before exposure runs them down, so breeding them before the rest of the herd might have the opposite effect you'd like, at least it did in my herd. I had one heifer that was really late one year, she's calved in 11 month windows ever since.

I wouldn't mind calving heifers 2 months later or so, but don't feel like having 1 long arsed calving season, so 24-25 months it is.. we did the 36 month calving thing for a while, that was just painfully too long to wait to get a calf from them, and they didn't really turn into much better cows.. only bigger.

 

[NEFarmwife]

We also did our set of Montana heifers that were 750lbs (some of ours wean at that!) and our success rate wasn't as good. They did breed but out of 120 heifers, we only had 70 that stuck to AI. Had another 20ish that got stuck the next cycle (bulls), and the rest a cycle or two later.

Are you breeding them on the same day, or on observed heat?

observed.

 

[Coosh71]

T&B, we also lutylase all heifers at weaning.

 

[Bright Raven]

I breed my Simmental heifers on natural observed heats at 13 to 14 months of age. Mine start cycling as early as 5 months. All are having regular cycles by 10 to 11 months.

At 13 to 14 months, mine will average 800 to 900 pounds. Those are estimated weights.

I also lutalyse the heifers at weaning in case one of their age group bulls is precocious.

All my heifers get a birth canal measurement at 12 months. I sell bred heifers under the Kentucky CAIP program and a Certified pelvic minimum score of I think 130 square centimeters is required.

 

[T & B farms]

Maybe I'm just picky, but I won't keep anything under 160 square cm.

 

[Texas Gal]

We run some Gelbvieh over Angus/Angus Hereford and Char cross cows. We have seen some not all, heifers start cycling at 7+ months. We do not breed at that age, but they are cycling. By 12-13 months our heifers are 750+ and we have no reservations putting our LBW RA bull on them. We do synch them to try to tighten the calving window. Last year we put a bull on 20 heifers at 12-14 months old and got 100% bred in 60 days. We like the Gelbvieh influence on our heifers fertility so far. This year we will do the same with 18-20 heifers that we like.

I've a group of 8 -9 month old super baldie heifers who are cycling regularly now. It's playing be nice on my grazing rotation since i don't want them near any bulls yet. We're trying to hold off until they're 13-14 months to breed. It appears my cattle did better through the droughty summer than I expected them to. :shock:

 

[Bright Raven]

Maybe I'm just picky, but I won't keep anything under 160 square cm.

The lowest score I have gotten is 162. That was at 12 month score. I have had as high as 222.7.

I think 160 is the minimum I would want on my farm with the birthweights I get. In fact, I want about 180.

 

[Ky hills]

I have always thought of 14-15 months being the ideal breeding age, regardless of when they start cycling. However have calved out several younger with not much problem at all. I like for our Angus/Hereford heifers to be at the very least 700 lbs and preferably 750-800 at breeding time. We have our heifers pelvic measured and the sale that we participate in has a requirement of 150 cm at yearling. Typically our calves are from 12-15 months at that time and usually anywhere from 1 to 5 out of 35 or so won't pass that. That is usually the younger or thinner calves but not always. I would say that on average most of ours will go 180 or better several usually measure over 200. We use low birthweight Angus bulls for our sale heifers, and most of what I retain as well. Have used a moderate Hereford bull on Hereford Heifers with no problems, but prefer to use Angus bulls on Angus or crossbred heifers.
On an average year we usually have some of our heifer calves cycling as early as 5 months, and have been getting them weaned by that time if the bulls are still with the cows. Used to let our Charolais calves stay on the cows for 7-8 months, with none getting bred early, then started using different bulls and some heifers were cycling by or before 7 months so started weaning them sooner. With Angus, or Hereford bulls our heifers will sometimes start cycling at 5 months.

 

[76 Bar]

Correct me if I'm wrong but I believe 160 square cm. was traditionally the minimum acceptable PM for yrlg bulls and heifers and sans an extreme regarding height versus width ratio.

 

[Bright Raven]

All my heifers get a birth canal measurement at 12 months. I sell bred heifers under the Kentucky CAIP program and a Certified pelvic minimum score of I think 130 square centimeters is required.

I checked the criteria for approval of funding for heifers under The Kentucky CAIP (Cost Share Program). It is as follows:

All heifers must have a 12 month pelvic score of 150 square centimeters or greater and/or a 18 month score of 180 square centimeters or greater.