Semen test are not always guaranteed. Each vet will use a different method, and rate the semen differently. I have seen 90% motility listed as "good" by a vet, but by the document standard (% scale on paper) put him in the Excellent catagory. I have also seen bulls make the paper's minumum standard, in his own hand writing, but not get the the Vets approval! Vets are very careful and critical when it comes to verifying semen in bulls they know you are selling as breed bulls. Their name is on that sheet and they don't want repercussions.
Trash (dirt), structure, and other factors do come into play besides just motility though. Remember, most bulls take "weeks" to produce new semen, so from bad to good in a few days indicates a bad read, or a bad test. Hot weather, infection, etc. does affect semen production, and can reduce the quality, but as long as the bull is healthy and has not been dormant or is a self ejaculator, then there should be no problem. Always run your young bulls together so they can jump each other, and keep newer semen present. Perhaps you friend had put this bull where he could purge the old stuff prior to being tested again.
The probe test is controversial although it is the most common. Manual stimulation of the prostate "may" net better results. I think mood has a little to do with it too...just kidding. I had yearling who was alone and not a self ejaculator. ( I'll hold my comments here..
) I took him to be tested and he came back at 50 or 55%. so they vet said "not an effective breeder" I imeadiately placed him with a small group of females. He bred every one! :shock: despite his semen quality. After using him to breed that group I took him back up to the vets. It still took two more times to verify him at 85% despite him already settling that group of cows.
If you take a bull to the sale barn to sell as an effective breeder, just get the vet to do the check and not the sale barn. (many stories exist about practices at sale barns and the sometimes good animals coincidently not making the standard but happen to sell back to the barn... ;-) ?) Then you can have the auctioneer announce he is being sold as an effective breeder, and you have the fertility test papers to go with him (and prove it. ) He will bring a better price this way, and you can always pull him if you want to.
Remember, some bulls will just flat be infertile, or become infertile over time without any logical explanation.
