Synching and gender

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dun

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Has anyone noticed a connection between synch calves and their gender? Like mostly bulls, mostly heifers, or does it seem to still work out around 50:50?
 

KNERSIE

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dun":35ajlwv3 said:
Has anyone noticed a connection between synch calves and their gender? Like mostly bulls, mostly heifers, or does it seem to still work out around 50:50?

With timed AI I get more heifers than with heat detection and using the am/pm rule whether it is synched heats or not.
 
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dun

dun

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KNERSIE":1g8r5pts said:
dun":1g8r5pts said:
Has anyone noticed a connection between synch calves and their gender? Like mostly bulls, mostly heifers, or does it seem to still work out around 50:50?

With timed AI I get more heifers than with heat detection and using the am/pm rule whether it is synched heats or not.
Interesting. 5 of the 6 calves born so far from times AI are bulls. Of course the one natural service calf is a bull also.
 

KNERSIE

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dun":kd19wz23 said:
KNERSIE":kd19wz23 said:
dun":kd19wz23 said:
Has anyone noticed a connection between synch calves and their gender? Like mostly bulls, mostly heifers, or does it seem to still work out around 50:50?

With timed AI I get more heifers than with heat detection and using the am/pm rule whether it is synched heats or not.
Interesting. 5 of the 6 calves born so far from times AI are bulls. Of course the one natural service calf is a bull also.

I guess it could just as easily to the other way if you started to AI a few hours earlier in your case.
 
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dun

dun

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mrvictordomino":2s0bojeb said:
Is there any scientific explanation for this or just luck of the draw so to speak
I was hoping there was but based on Knersies results it must have to do with the ovulation time of the cow and the timing of the AI. Other then that it probably is luck of the draw. I think we have 5-6 more due to calf from the same sync so maybe they'll all be heifers.
 

Alan

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mrvictordomino":23l09fv8 said:
Is there any scientific explanation for this or just luck of the draw so to speak


No science that I know of, but I spent a lot of time in horse barns when I was a bit younger, I have been told by a few different barns that in horses if you want a filly, breed the mare early in the cycle and a colt breed late in the cycle. The reason being is the male sperm die faster than the female but are faster swimmers, therefore early in the cycle the hope is the male sperm die and leave the egg to mostly female sperm and vise versa....... honestly it may be total BS but a few knowledgable horse people have said this to me throughout the years.

BS or not you decided.
Alan
 

novaman

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The first year I AIed my dairy cows I got 64% heifers. I have no idea what went on there because I haven't gotten above 47% since. Not sure if it had to do with the timing of the insemination or not. I did breed a bit earlier that season as I was green and worried about getting to them late. Haven't been able to duplicate the results though. I didn't do any synching that year.
 

Stocker Steve

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Alan":y71yw1ni said:
I have been told by a few different barns that in horses if you want a filly, breed the mare early in the cycle and a colt breed late in the cycle. The reason being is the male sperm die faster than the female but are faster swimmers, therefore early in the cycle the hope is the male sperm die and leave the egg to mostly female sperm and vise versa.......

So sexed semen comes from a swim meet ;-)
 

KNERSIE

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Alan":26deb8qj said:
mrvictordomino":26deb8qj said:
Is there any scientific explanation for this or just luck of the draw so to speak


No science that I know of, but I spent a lot of time in horse barns when I was a bit younger, I have been told by a few different barns that in horses if you want a filly, breed the mare early in the cycle and a colt breed late in the cycle. The reason being is the male sperm die faster than the female but are faster swimmers, therefore early in the cycle the hope is the male sperm die and leave the egg to mostly female sperm and vise versa....... honestly it may be total BS but a few knowledgable horse people have said this to me throughout the years.

BS or not you decided.
Alan

There is truth in it, the reproductive tract of the cow changes pH during the cycle and the breed early for heifers later for conception rates definately applies to cows.
 
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dun

dun

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KNERSIE":1elj5mnd said:
Alan":1elj5mnd said:
mrvictordomino":1elj5mnd said:
Is there any scientific explanation for this or just luck of the draw so to speak


No science that I know of, but I spent a lot of time in horse barns when I was a bit younger, I have been told by a few different barns that in horses if you want a filly, breed the mare early in the cycle and a colt breed late in the cycle. The reason being is the male sperm die faster than the female but are faster swimmers, therefore early in the cycle the hope is the male sperm die and leave the egg to mostly female sperm and vise versa....... honestly it may be total BS but a few knowledgable horse people have said this to me throughout the years.

BS or not you decided.
Alan

There is truth in it, the reproductive tract of the cow changes pH during the cycle and the breed early for heifers later for conception rates definately applies to cows.
I had pretty well dismissed the early late breeding deal with these cows since some of them were on observed heats and others we time bred and gave a shot of GnRH. We bred them all at the same time, the observed heats were having seen their patches rubbed shiny red.
 
A

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If anyone figures it out they could make a mint. There way too many variables to nail down. Just look at this years calving/breeding issues with the heat/drought, and you've got a pretty good idea of all the things that COULD decide what the sex is, much less other issues. From what I've researched , even sexed semen is a toss up
 

Alan

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Stocker Steve":1pn0q3k7 said:
Alan":1pn0q3k7 said:
I have been told by a few different barns that in horses if you want a filly, breed the mare early in the cycle and a colt breed late in the cycle. The reason being is the male sperm die faster than the female but are faster swimmers, therefore early in the cycle the hope is the male sperm die and leave the egg to mostly female sperm and vise versa.......

So sexed semen comes from a swim meet ;-)

Actually , I'm fairly sure sexed semen comes from a centrifuse, females are larger and get separated that way. ;-)

Alan.
 

Suzie Q

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Our bull is out with our calves 24/7. We get calves all year, not just for one period of the year.

The first year equalled drought. There is not so much to share around, so mostly heifers, as nature can not be frivolous and does not have extra to feed bulls that are not needed to continue the species.

The next year, same bull, same cows and flooding. A bumper grass crop and mostly bulls as nature can now be frivoulous and feed them.
 

whitecow

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Alan":3zafyewb said:
Stocker Steve":3zafyewb said:
Alan":3zafyewb said:
I have been told by a few different barns that in horses if you want a filly, breed the mare early in the cycle and a colt breed late in the cycle. The reason being is the male sperm die faster than the female but are faster swimmers, therefore early in the cycle the hope is the male sperm die and leave the egg to mostly female sperm and vise versa.......

So sexed semen comes from a swim meet ;-)

Actually , I'm fairly sure sexed semen comes from a centrifuse, females are larger and get separated that way. ;-)

Alan.

Centrifugation doesn't work very well. This is the method currently used by all of the AI studs....

http://www.sexingtechnologies.com/articles/technique

There is some evidence that male sperm swim slower than female, but it would take a VERY large study to show a statistical difference in the number bulls vs heifers based on insemination timing. There are still lots of variables like semen quality, capacitation, when ovulation actually occurs. I've heard lots of anecdotal evidence that timing of insemination affects gender ratios, but I haven't seen any well-controlled studies that show significant, repeatable results.
 

Alan

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Well like I said it is just what I have been told, you guys guess if it is BS or not, so is what happens when I try to post a thought.

Sorry for the bad info,
Alan
 

whitecow

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Alan,

My apologies. I did not mean to offend you. Bovine reproduction has been my life for most of my professional career. I guess I pounced. Again, my apologies.

-Brian
 

Stocker Steve

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Suzie Q":32wutgw2 said:
Our bull is out with our calves 24/7. We get calves all year, not just for one period of the year.

The first year equalled drought. There is not so much to share around, so mostly heifers, as nature can not be frivolous and does not have extra to feed bulls that are not needed to continue the species.

The next year, same bull, same cows and flooding. A bumper grass crop and mostly bulls as nature can now be frivoulous and feed them.

My wife thinks I am frivolous at times...
 
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dun

dun

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Make that 6 bulls 1 heifer from the synced cows, 5 or 6 more to go
 

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