Jeff we store our own semen as well as other folks semen, and have rather large tanks and bought them all brand new. I am not home so I can't look up the hold time on them right now, but I have to say it is something like 2 months. The time varies depending how much you open the tanks of course. Buying used could be just fine for you. But you need to be sure the tank is checked then. Some if mishandled can have an ever so small leak. But be significant enough that you would not want the tank. Personally I would buy new but that is just me.
We actually don't wait very long to top off the tanks with additional nitrogen each time. We keep the tanks right up at or near the top. The longest we may ever go is about 3 or 4 weeks before topping the tanks off again, but most times it is only 2 or 3 weeks. This is for a couple of reasons. One is we have a shipper tank we send back and forth fairly often delivering or picking up straws. When we get the shipper tank charged we just get addition nitrogen for the storage tanks at that time. The second reason is I am pretty anal about how I care for the semen we have and would prefer to just fill them more often.
If you have your own storage tank I would highly recommend NOT taking it to town each time to have it filled. It is just simply to risky to the semen. Instead for $50 or so buy a used piece of junk tank to take to town and have filled. Then take that back home and pour it into the storage tanks to top them off.
Keep the storage tanks in a safe place, off any concrete floors so condensation is not an issue, also where they won't be knocked over, or bumped in some way. Keep them in an area where you will see them everyday and take notice if there is any signs of leakages such as misting or frost.
When you do open your tank you should see the "frost line" in the neck of the tank. NEVER lift a cane of straws above this frost line except when removing the cane from the tank. In less than 2 or 3 seconds the semen will already start to thaw around the outer edge of the straw. This can cause the number of viable sperm in that straw to drop significantly if this occurs a couple of times. In my personal opinion poor straws are less often from the initial processing and more often from poor handling after being frozen.
The only other comment I will make is storing your own semen most likely won't be cheaper for you. Nitrogen has gone up in price a BUNCH over the past 2 or 3 years. I think for the average guy who has maybe a dozen straws or whatever and they just simply need the straws stored for the year and they don't have straws going into or out of their account very much, they are better off paying a storage place to keep their semen for them.
Really I think the only place that some of the well known and well used semen storage places rape the customers is in the "handling fees" they charge. I have heard of some of these places charging a fee for putting straws into the account and a fee for removing the straws from the account and then a fee for charging the shipper tanks, and then another fee for the shipping cost. One guy said that place "X" would have charged him $125 just for the shipping cost alone. WOW! Hookers in Hong Kong cost less
I know for a fact the shipping costs are no wheres near that much.
That said if you have your straws stored at one of these places keep in mind they get busy from about Sept 1st until the end of Dec shipping straws around the country. You will want to have your own tank for when you need your straws sent to you for the actual a/i date. Then take that tank and have it charged and have your straws sent to you about late Sept or early Oct so you have them at your place in plenty of time for a/i. The last thing you want is to have the does ready to breed and now your still waiting for the straws to show up because they couldn't send them soon enough because they were to busy.
Just some thoughts to keep in mind is all.
Roger
