I collected a friend's older pony stallion to clean it out before shipping later in the week. He seems to be an accumulator. This collect was only 25 ml with a concentration of 256 million/ml and a progressive motility of 20% (that might be generous).
I saw in a previous post you said "Bear in mind when extending for shipment that you need to calculate your final concentration of between 25 and 50 million/ml based upon total sperm numbers, as all sperm will use the nutrients in the extender."
I thought if the strange that the dead sperm use the nutrients in the extender. I would of thought I needed to feed just the live ones?
According to the semen calculator the dose would require 1 part of semen to 9.2 parts of extender reguardless if you calculated total sperm or progressive motility. If using a total sperm calculation method you will need to use 5.9 ml's of raw semen and 54.1 ml's of Extender. With 20% PM the dose would require 19.5 mls raw semen and 180.5 mls of extender. Of course it would have to be centrifuged I understand that but why do I have to feed the dead ones? Thanks,
The sperm don't "eat" the nutrients and buffers, but absorb it. While the cell membrane is undoubtedly compromised in a dead sperm, it does not lose it's ability to absorb.
Think of eosin-nigrosin sperm stain. The "good" sperm (those with intact cell membranes) reject the eosin stain and show as white in the black (nigrosin) background, while the ones with compromised cell membranes (the dead sperm) stain pink - because they absorbed the eosin.
On the calculator, the total sperm calculation is merely calculating the total volume required to send x (typically 1) billion sperm total, while the progressive motility calculation is calculating how much volume is required to send x billion progressively motile sperm. As the raw concentration (i.e. total number of sperm/ml) is the same for both, the dilution factor is going to be the same even though the volume needed to ship the required numbers will change.
256 million/ml raw concentration is not all that high. While several collections in a row will probably assist in improving progressive motility, it is also probably going to result in a reduction of concentration, which in turn - if low enough - may prove an issue. Typically accumulator stallions will have concentrations higher than that - I would expect to see >400 million/ml - however, he could still be an accumulator that does not produce many sperm and that could present problems for you. Do not attempt centrifugation unless you are getting a reasonably good degree of motility. If you centrifuge an ejaculate with a high percentage of dead sperm, you will end up with a hard packed sperm layer/pellet and that will have a negative impact on the remaining (healthy) sperm as resuspending will be difficult without damage.
Thanks, Jos "Think paper towel, not pacman!" OK, I got it, that makes sense. I did kind of think of them as Pacmen with tails. I love your semen calculator.
He will be going to a vet clinic when he has to be shipped, I was just collecting him to clean him out and to take a look at his semen. He is only bred a couple times a year, mainly due to his poor quality semen, no one has ever documented his actual output other than saying his collection is poor, thin, anemic...no actually numbers. Due to cost they only cleaned him out once before collecting him to use the semen to breed a mare, he does get mares infoal. I was curious if his concentration and PM would improve with more cleaning out collections. Thought it would be interesting to see if his collections improved with collecting a couple of times a day, once a day or every other day, the problem is the pony lives an hour away so I probably won't be able to put him in a program to try and improve his collections.
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