Fertility of AI bulls

[S J H]

Just scanned today, I have used 4 different bulls, I only served 2 cows to 1 bull and they haven't taken, just wondered if the fertility of straws differ? I know people say Welsh black is very fertil, but never knew if there was any truth in it.

 

[AGN76]

Plenty of truth!

 

[M-J-G]

Semen on collection is normally diluted dependant on concentration, so conventional straws should be at a similar strength.

However some bulls have superior fertility to others, some freeze better than others and some thaw better than others.

Straws being handled or stored improperly will have a vastly negative effect.

If you have straws left you could always get one tested.

Since it's only 2 cows, so not very conclusive, if it was 20 that were all empty it would be more definitive.

 

[S J H]

Sorry I lost this thread for some reason, yes I'm not overly worried,

I'll see after calving, what the bull got, but it's interesting to know.

 

[S J H]

Plenty of truth!

Hopefully hamlet did ok. ?

 

[Whitepeak]

Just scanned today, I have used 4 different bulls, I only served 2 cows to 1 bull and they haven't taken, just wondered if the fertility of straws differ? I know people say Welsh black is very fertil, but never knew if there was any truth in it.

Why do you think ai studs have so many full brothers
A friend worked at Ruthin for their placement year and they said that a lot of bulls, particularly Blues, were very temperamental producers. Ie. thunderstorm the night before, or new handler, or slight change in routine, and the bull wouldn't perform!

 

[S J H]

Why do you think ai studs have so many full brothers
A friend worked at Ruthin for their placement year and they said that a lot of bulls, particularly Blues, were very temperamental producers. Ie. thunderstorm the night before, or new handler, or slight change in routine, and the bull wouldn't perform!

I don't know why I hadn't questioned it before, I just presumed it was all tested and of much high concentration than natural service.

 

[M-J-G]

Why do you think ai studs have so many full brothers
A friend worked at Ruthin for their placement year and they said that a lot of bulls, particularly Blues, were very temperamental producers. Ie. thunderstorm the night before, or new handler, or slight change in routine, and the bull wouldn't perform!

On the poor fertility in BB cattle, there is a correlation between extreme muscled types and poor fertility, although it's often not talked about as it upsets too many breeders.

Most bulls will produce poorer quality semen due to stress, and because these extreme muscled breeds tend to have poorer semen anyway, a further drop is more noticeable.

What is your theory on AI stations keeping brothers?

 

[Whitepeak]

What is your theory on AI stations keeping brothers?

Well they never tell you which bulls are in the mixed straws. So if they have full brothers when one isn't performing they still have a very similar one to go in the mix.

 

[M-J-G]

I don't really see any point in that, even if it was for unidentified straws where they can use anything they like (which I'm not sure is allowed these days), I'm not sure why they would restrict themselves to a particular family.

Plus, brothers are only likely share around 50% genetics, so are unlikely to breed the same.

 

[Qman]

Well they never tell you which bulls are in the mixed straws. So if they have full brothers when one isn't performing they still have a very similar one to go in the mix.

If you look on the mixed straw they have the codes of the bulls used.

 

[jellybean]

I have some experience of AI in deer and have learned a bit because we do our own semen collection and processing on the farm. Semen dilution is whatever you want it to be but obviously needs to be such that you have reasonable expectation of pregnancy from one straw. When we started off we were putting 30-40 million sperms per straw but subsequently discovered that if you are selling fairly expensive straws some people will split straws and inseminate 2 hinds therefore getting calves at half price. Now 23 million is the number considered fair.

Semen quality is another matter altogether and depends on many factors. The vet who does mine is one of the world experts in this work and says that if you take each of the steps in the process (and there are many) and try to improve each step by 10%, the cumulative effect of paying such attention leads to top quality semen. BUT every time we collect, the semen is frozen and then sample straws are thawed out and examined under the microscope for
sperm quality and forward motility, after a few minutes, after 30 minutes and maybe longer. Some sperm takes longer to get going. Any semen that has a forward motility of less than 80% is binned.

If you are suspicious of the quality of semen you are using get a straw tested by someone who knows the job. Maybe not so important with cattle but the cost of doing an AI program in deer is such that it is worth checking every step is done correctly.

 

[som farmer]

our ai chap allways says, look at a straw under a microscope, for each batch. Needless to say, we don't.
But we should, semen/straws go through several handlings, before it ends up on farm, any of which could damage quality, and, unless someone is honest, we would never know, and would blame, inseminator, bull or whatever, a sacrifice straw is probably very cheap!

 

[Paul E]

What is your theory on AI stations keeping brothers?

It's usually because they do breed similar, and they are easier to sell if it's related to another bull. (assuming it's good)