I am new to the subject of breeding horses by shipped semen.  Is it customary to only ship half a syringe of semen?  We tried breeding two different fertile mares to Stoli at Hart Farms with no success and are wondering if this could of been a factor for failure.

I would address this directly with Hart Farms.  Also this is an issue that should have been addressed immediately. You probably used a vet or someone who was familiar with the AI procedure and would have questioned the amount of semen shipped. Hart Farms is very professional and easy to work with but several months after the fact leaves you with little to go by. There should have been a sheet with the shipment saying she it was collected and sperm count etc. 

In Shipped semen, volume means very little.  They can send you a 5 gallon bucket but if it doesn't have enough progressive sperm cells it still wont do any good.  

Half a syringe doesn't mean anything.  

A breeding dose goes by # of motile sperm cells, which ranges between 500 million to 1 billion progressively motile sperm.  The total volume of an insemination dose we like to keep at the max 60 ml including extender, but if we can get it done in less than that we totally do it.  More is not always better.  

So, back to my first statement- If your breeding dose is 30 ml (with extender) and you put it in a 35 ml semen syringe, you get a whole syringe.  If you put that same breeding dose in a 60 ml semen syringe- you get half a syringe. It's the correct breeding dose, just packaged in a differnet syringe. 

I always have the vet I’m using check semen.. numbers, healthy swimmers as soon as possible.  This way you will know if you got a good shipment or you need to have a POW wow with whomever is collecting and extending.  If this is good then, I start trying to figure out if my mares are reproductively problematic, and that can be challenging since there are so many things that can be wrong.  The last thing, and I hate to say it, but I’ve had it happen, some vets are just better at predicting ovulation, and have better procedures pre- and post insemination.  Therefore produce higher conception numbers than others.

Did your vet do a culture on both mares?  We always had a set of procedures we perform on our mares to ensure they were prepped for breeding season. 

Make sure they’re not eating fescue! I had 2 separate mares not get into foal or get into foal and lose pregnancies. Come to find out, my pasture had some fescue. Took one mare off and she caught and stuck right away. 

I know a few months have pasted since I posted originally but contacting the owners at Hart Farms was difficult.  I had to write them a letter.  The bottom line is we were collateral damage to an employee problem at the stud farm.  I was told if I had bought the stallion service through them instead of TX A&M's stallion service auction the problem would of been handled differently.  IMO stay away from stallion service auctions and Hart Farms!

Sorry to hear this.  I feel the same way about stallion service auctions.  Never again.  

Whoever told you that should not be in business.  An ethical business would never treat someone differently for buying the breeding through an SSA.  Also the SSA should have a rule in place for when things go wrong as can happen when breeding horses.    

As already stated it doesn't matter the quantity, it is all about the quality. Another factor I would look at is what is your vet's success rate? The local vet in my home town has a success rate under 30%, so I take my mares 70 miles to a vet that personally has a 100% success rate with my mares (I have bred from 2 to 4 a year for the last 4 years). Getting a good repo vet is extremely important.