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Faunsdale, AL | While it "only takes one", all good quality embryos have mulitple "accessory sperm" inside the zona. So while it really does take just one to bring the DNA, the others have some sort of effect that promotes development or maybe their presence is the sign that that egg was somehow better than others which only had a single sperm penetrate.
The biggest problem with sexing semen from species other than bovine is the lack of efficient freeze/thaw protocols. Without that, you have to have the laboratory next to the collection facility/sire housing like the bulls are, but you also have to be close enough to the females to use the semen fresh.
The other thing that works against the process being used in swine is the time it takes to sort the sperm with the current technology. The volume/number of spermatozoa required for inseminating a sow (old reference I have says 2-3 billion live/normal/motile sperm) would be many times the amount needed for AI in cows (10 million live/normal/motile). So even accounting for the number of bovine sperm that are lost in feezing and thawing, each dose to breed one sow would still require 100 times as many sperm. So the machine time to produce a single dose for a sow is 100 times greater. At some point the process of increasing the number of sorted sperm in a single dose becomes impossible since the increase in time before freezing results in more loss of viability in the sorted sperm than is being gained by sorting longer. The main problem is still economic, each dose just gets too expensive for the market if it takes too much machine time.
I've seen from 150 straws from a single collection to as many as 400 on some of the bulls we have had custom frozen.
Edited by ccjersey 3/9/2012 13:17
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Dairy, hog guys, sexed semen?
