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AI -Gestation Period

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James T

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For those of you who AI: is there any difference in the gestation period for AI'd cows as opposed to non-AI'd? I know that for Brahman influenced cattle the period is a little longer for non-AI but, I do not know if being AI'd adds to that time frame. Thanks in advance for any information on this!
 
James T said:
For those of you who AI: is there any difference in the gestation period for AI'd cows as opposed to non-AI'd? I know that for Brahman influenced cattle the period is a little longer for non-AI but, I do not know if being AI'd adds to that time frame. Thanks in advance for any information on this!
Click to expand...

No.

The genetics are the same---if for some reason you used the same bull for cleanup as you got the semen from==which ain't gonna happen--the gestation length should be identical.

But--different bulls could have different gestation lengths and different breeds certainly seem to---the hereford line i use seems to be close to 282-285, the blacks i buy seem to be a little quicker.

Odd some of the stuff people will tell you--i had an old friend (who has a.i.'d thousands of cows---tell me that a bull will throw bigger calves as he gets older. I thought he was kidding--but he wasn't. Same deal---the genetics are the same. And--as always---the cow is half the equation.
 
Thank Little Joe. I have two that were AI'd on the same day and both took (verified by ultrasound a few weeks later). One is a heifer and the other has already had two calves but both are already at 307 days. I'm no so much concerned about the cow as I am the heifer.
 
James T said:
Thank Little Joe. I have two that were AI'd on the same day and both took (verified by ultrasound a few weeks later). One is a heifer and the other has already had two calves but both are already at 307 days. I'm no so much concerned about the cow as I am the heifer.
Click to expand...

Pretty hard to believe they conceived 307 days ago. My Brangus & Brahma X Angus crossbreds average calving at 284-285 days. Never had one go past 295.

My guess is they caught on the next estrus period.
 
Thanks C. How does that work? The cows were brought into heat (timed protocol - no gomer bull) and then AI'd by the vet. So, your saying that the sperm and the egg maybe didn't link up at that point but maybe linked up at the next cycle? The semen lasted long? These are Beefmasters so the brahman genetics might have carried them out a little longer but now they are out to 308 days.

I'm starting to wonder if the neighbors bull didn't jump the fence and have a little party!
 
littlejoe said:
James T said:
For those of you who AI: is there any difference in the gestation period for AI'd cows as opposed to non-AI'd? I know that for Brahman influenced cattle the period is a little longer for non-AI but, I do not know if being AI'd adds to that time frame. Thanks in advance for any information on this!
Click to expand...

No.

The genetics are the same---if for some reason you used the same bull for cleanup as you got the semen from==which ain't gonna happen--the gestation length should be identical.

But--different bulls could have different gestation lengths and different breeds certainly seem to---the hereford line i use seems to be close to 282-285, the blacks i buy seem to be a little quicker.

Odd some of the stuff people will tell you--i had an old friend (who has a.i.'d thousands of cows---tell me that a bull will throw bigger calves as he gets older. I thought he was kidding--but he wasn't. Same deal---the genetics are the same. And--as always---the cow is half the equation.
Click to expand...

That's very interesting--I had never heard that before. We used a bull on heifers for 2 years with great success. The third year the calves were much bigger and it hadn't been a real cold winter (this was in SW Montana). We couldn't figure out why that happened and we visited with a neighbor who
had the same thing occur. Same bull, used two years, no problems, the third year the calves were bigger. So perhaps what happened was what your friend has observed--older bulls throw bigger calves. We hardly ever keep a bull past 4 or maybe 5 years old cuz they start causing trouble, so we hadn't really noticed bigger calves out of the cows. I do know that heifers will throw a calf with 10# less bw than a cow bred to that same bull.

Genetics are always interesting. Thanks.
 
I hope your right about that 10 lbs lighter for a heifer FH! Anyway, found out the days were wrong. Today is day 301, not 307. The local ranch foreman said to have the chains ready. What would be the odds that 2 cows, AI'd on the same day, would be this late? Am starting to think that the neighbors bull hopped the fence.
 
I'm hoping that I'm wrong about that. My brother had to visit my vet today about a structural job with her building and I asked him to throw the issue her way. She AI'd them for me and also ultrasounded them. Get this, she tells him that they could go a month overdue and to cease feeding any supplements like sweet feed or range cubes as that can prolong the gestation period. A month? The supplements I understand but a month? I'm no pro-rancher or anything and have run a small herd (32) Brangus for several years and never had one go a month out. In any case, we'll see, and soon. Sure would like to see the results of the AI work though instead of taking the proceeds to the salebarn.
 
Faster horses said:
Most vets don't know much about nutrition or feed. So I wouldn't take what was said as gospel. :D
Click to expand...

Working cows yrs ago with very competent vet--"say, do you use mineral?" 'what kind, how come, when, etc?"

Well---Ya---but why are you asking me---din't you go to school and learn this stuff??!!

He said he'd had maybe 8 hours of school on it, in entire process. And i think that many of the people that sell it mostly just know what it costs and what they got. Both baffled me.

ON a.i. calves, we've probably had them up to 20 days either side of 'due' date. Seems like heifers more apt to come early, bulls late. On 'hi accuracy' bull---ext---birth weights varied from 68# to almost 110. But---cows we had then were quite the mixed bunch..

Faster Horses---you might have misunderstood me: i said the guy believed older bulls threw bigger calves. I do not believe it.
 
"And i think that many of the people that sell it mostly just know what it costs and what they got. Both baffled me."

I've learned a bunch about nutrition and immune system in the past 19 years. I became a Vigortone dealer in
1994. Our company teaches their dealers and the object is to help our customers, not just sell them something. It's been fun and very rewarding to have people come back and tell you how much you have helped them! In 1993 I knew nothing, except our calves had gotten sick for 8 years and no one knew why! What a relief to finally find out what caused it. Talk about
a learning experience! I wouldn't wish that on anyone!!
 
Faster Horses---you might have misunderstood me: i said the guy believed older bulls threw bigger calves. I do not believe it.
Click to expand...

And you would be correct.

Inversely, younger bulls don't have smaller calves.

A bull's genetics do not change over time. The same 30 pairs of chromosomes he was born with goes with him to that big pasture in the sky.
 
Getting back to the topic, there is some evidence that these calving ease sires used for AI are getting the accuracies because their calves have a shorter gestation length.
 
Mike said:
Faster Horses---you might have misunderstood me: i said the guy believed older bulls threw bigger calves. I do not believe it.
Click to expand...

And you would be correct.

Inversely, younger bulls don't have smaller calves.

A bull's genetics do not change over time. The same 30 pairs of chromosomes he was born with goes with him to that big pasture in the sky.
Click to expand...

Hummmm. The ABS person here that is very knowledgeable says the calves out of 2 year olds are 10 lbs lighter when that same bull is bred to cows.
But I'll take your word for it.
 
Faster horses said:
Mike said:
Faster Horses---you might have misunderstood me: i said the guy believed older bulls threw bigger calves. I do not believe it.
Click to expand...

And you would be correct.

Inversely, younger bulls don't have smaller calves.

A bull's genetics do not change over time. The same 30 pairs of chromosomes he was born with goes with him to that big pasture in the sky.
Click to expand...

Hummmm. The ABS person here that is very knowledgeable says the calves out of 2 year olds are 10 lbs lighter when that same bull is bred to cows.
But I'll take your word for it.
Click to expand...

Sounds like a heckuva salesman. :D

Nothing changes in the bull's makeup but age and bodyweight, how can the BW of progeny change unless the dam's BWs were heavy or light?
 
Faster horses said:
Mike said:
Faster Horses---you might have misunderstood me: i said the guy believed older bulls threw bigger calves. I do not believe it.
Click to expand...

And you would be correct.

Inversely, younger bulls don't have smaller calves.

A bull's genetics do not change over time. The same 30 pairs of chromosomes he was born with goes with him to that big pasture in the sky.
Click to expand...

Hummmm. The ABS person here that is very knowledgeable says the calves out of 2 year olds are 10 lbs lighter when that same bull is bred to cows.
But I'll take your word for it.
Click to expand...

So---was he talking 2 y.o. heifers?
 
Feed makes a differance in bithweight along with weather.... I agree with the rest.... Epds are what they are and can't change with an animal getting older...


Edited to add: what the heck do I know!!! I'm still trying to get in those tight wranglers..... And don't ask for pictures......
 

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