want replacement heifer!

ordinary farmer

lads im sure all of u have being in the situation where u had an old cow that u want to get a heifer calf out of. wel 2 day i have one starting to come a bulling i was wondering is there any bull thats bringing heifer calves. the cow is a big 800kg black 11 years old.
regards O,F

Bizzum

I heard several theories but I still find that generally we get a ratio of 50:50 bulls to heifers over time.
You could try sexed semen, but the trade off here is lower conception rates, and lower sire choice.

pakalasa

No, they all bring a 50:50 ratio. You can check the figures on www.icbf.com, all bulls are close to the 50% mark for bull:heifers.

ordinary farmer

Bizzum wrote: »

I heard several theories but I still find that generally we get a ratio of 50:50 bulls to heifers over time.
You could try sexed semen, but the trade off here is lower conception rates, and lower sire choice.

is there sexed semen availble to buy or wud the AI man have it in storage.?

Bizzum

ordinary farmer wrote: »

is there sexed semen availble to buy or wud the AI man have it in storage.?

It's unlikely the AI man would be carrying any but ya never know. The selection is very very limited, I only know of a couple of bulls off the top of my head. The Charolais Soc has one called Snoopy and Sligo AI have one called Clyth Diplomat. They aint cheap either.

If it was me I'd be picking a decent bull with good maternal traits and hope for the best.

blue5000

I think years ago NZ farmers/research found that the earlier the cow is served when standing heat occurs, with ai the more likely she is to have a heifer calf.

AFAIK the theory is that female sperm are faster swimmers and reach the egg sooner whereas the male sperm swim slower but survive longer. I think they were getting 55:45% female:male calves this way.

Anyone know more?

pakalasa

Someone mentioned that on here before alright - Ai early to get heifers!!

Richk2012

I remember when i was doing the course to A.I , we were told that its not written in stone but , if you thaw the straw at exactly at 37deg its more likely to bring a heifer , where as if you drop the temp back to 35deg your increasing chances of a bull .
I dunno tho i must have a dodgy thermometer :rolleyes:

Bodacious

Same as OP,

Killed my best cow last year and she was a gem 21 years and didnt hold and last 9 calves were bulls! Balls she never left me nothing in the line of a heifer

ordinary farmer

Bodacious wrote: »

Same as OP,

Killed my best cow last year and she was a gem 21 years and didnt hold and last 9 calves were bulls! Balls she never left me nothing in the line of a heifer

im lucky enough that i have 2 sucklers bred from this cow on on the farm. she had a heifer calf last year she wil be one for keeps but again this year a bull only have 3 heifers from 11 calves :rolleyes:

Bizzum

ordinary farmer wrote: »

she had a heifer calf last year she wil be one for keeps

What are the 2 suckler cows and last years heifer off her bred by?

ordinary farmer

Bizzum wrote: »

What are the 2 suckler cows and last years heifer off her bred by?

two cows bred by DVE and this years bred by my own stock bull but she had 3 bulls from him before this :rolleyes:

furandfeather

blue5000 wrote: »

I think years ago NZ farmers/research found that the earlier the cow is served when standing heat occurs, with ai the more likely she is to have a heifer calf.

AFAIK the theory is that female sperm are faster swimmers and reach the egg sooner whereas the male sperm swim slower but survive longer. I think they were getting 55:45% female:male calves this way.

Anyone know more?

Ya have the right idea but the wrong way around;)
The male sperm is the sprinter but dies quicker
The female sperm is slow and steady, but lasts longer !!
The cow doesnt drop the egg until about 12 hours after first sign off heat thereby if you AI earlier your kinda increasing your chance off a hiefer as the male sperm has died off by the time the egg has dropped. BUT your decreasing your chance off getting a pregnancey because your only relying on half off the sperm.
That very simplystic view on it as every cow is different as you know

Bizzum

furandfeather wrote: »

The male sperm is the sprinter but dies quicker.The female sperm is slow and steady, but lasts longer !!

Is it not the case that sperm contains a pair of sex chromosomes XX and the egg contains XY, thus giving four outcomes when crossed. XX XY XX XY. 50:50 male female.
I dunno what a "female sperm" is:)

bogman_bass

No he's correct. There is both male and female sperm. Thats how sexing technology works. The male sepm are slightly larger so the sexing machine detects this and knocks out the male sperm with a laser

Bizzum

bogman_bass wrote: »

No he's correct. There is both male and female sperm. Thats how sexing technology works. The male sepm are slightly larger so the sexing machine detects this and knocks out the male sperm with a laser

Is flow cytometry used? And if so is it not on the base of light emission?

bogman_bass

Bizzum wrote: »

Is flow cytometry used? And if so is it not on the base of light emission?

since the companies that are using sexing are quite secretive about the method I'm not 100% but yes it is flow cytometry but as far as I know its particle size thats used to determine the gender with light refraction to differentiate between sperm and other particles.

You sir, know your s*1t!

Bizzum

bogman_bass wrote: »

since the companies that are using sexing are quite secretive about the method I'm not 100% but yes it is flow cytometry but as far as I know its particle size thats used to determine the gender with light refraction to differentiate between sperm and other particles.

I read a good bit about it when it was the next "great white hope". There was a time I thought I'd be ringing the AI man and telling him whether it was a bull or heifer I'd be looking for. It never quite worked out like that..........Maybe just as good:)

Dont be daft

Bizzum wrote: »

I read a good bit about it when it was the next "great white hope". There was a time I thought I'd be ringing the AI man and telling him whether it was a bull or heifer I'd be looking for. It never quite worked out like that..........Maybe just as good:)

Is it physically possible to create 100 or even 90% sexed sperm?

We've made a big investment with dairy bull beef system in mind but its been in the back of my head that if sexed semen became more reliable the system we run would be dead in the water.

bogman_bass

Dont be daft wrote: »

Is it physically possible to create 100 or even 90% sexed sperm?

We've made a big investment with dairy bull beef system in mind but its been in the back of my head that if sexed semen became more reliable the system we run would be dead in the water.

cogent in England claim 90% female. the process knocks hell out of the semen though so thats why its for heifers only. price is the other issue

Dont be daft

bogman_bass wrote: »

cogent in England claim 90% female. the process knocks hell out of the semen though so thats why its for heifers only. price is the other issue

I'm off to google "slatted house to cubicles conversion"

smgkilmore1234

clyth diplomat all the way

Damo810

Pray to god for a bull, chances are that way you'll get a heifer!