Thanks
@kenny thomas for the vote of support. I am not sure I am an expert... and there are vets on here that seem to have their own opinions.
@ez14. has worked on a dairy like I did and had lots of exposure experience.
There is not any reason to think that a 3 quartered cow will have more mastitis problems down the road. Or lose another quarter. BUT, it is a toss up. I bought a bred jersey heifer, that had a bad quarter as a heifer.... probably sucked by another calf.... or fly infections that seemed to hit here every so often and several heifers will come in fresh with a bad quarter.... The quarter had no milk and she was a 3 teat. Sadly, the next year another one was light, although it had milk. By her next lactation, she was basically a "2 tit" cow. Raised 2 calves that year... came up open... down the road.
I have seen dairy farmers with 3 quartered cows for several lactations. Some seems to depend on what caused the 1st quarter to go bad.
As a rule, many cows that are 3 quartered.... with one that dried up or got mastitis and was not milked any more, TEND to have a higher somatic cell count. Especially if it is cultured and is a staph problem. Staph is a real B#$*@H to get rid of and becomes a chronic problem.
That said, I have had cows with a mastitis problem that have cleared up when used as a nurse cow.... because the calves will keep at the quarter, getting it milked out and keeping it emptied....They butt the udder and it tends to soften and break up the hardness of the whole area. Sometimes they will come in with good milk in all quarters.
IT IS A CRAPSHOOT...... Maybe.... maybe not.
If you are near any dairies, and they are "on test", talk to one and ask if you can get a milk sample checked.... through their DHIA testing. What I do is "put a cow on test" ....and then take the sample from the "private cow" and it gets run through. This is how we do it.... The farm has a "new cow" that is bought "on the records". You "give her a milk weight" like she was run through the dairy with their cows. You put her milk sample through and they get the result and you get all the info you need. Okay.... "Bessie Mae" is "bought" and added to the herd... She is number 1 or 100 or 1000 or 999 or whatever number.... You record her "calving date".... so she can "enter the herd" so she can get a "status". Then say she is making 25 lbs a milking or 50 lbs a day or whatever.... her sample gets processed, and the farms most all test for butterfat, protein, and SCC (somatic cell count). It goes to the lab, gets checked and the farmer gets back the results. You check with him a few days after the test to see what her "cell count is" . If you never do it again, the farm "sells her" out of the system. If you want to do it more, then every month they test, you get them a sample the day before their test day, and give them a "milk weight".... and it gets run through.
You offer to give them a couple dollars towards it... most farms 50-150 cows the sample and being on test is about $2-3.00 each month.
You can contact your state lab, and they will run samples ... but I have no idea of the charges. Some labs do specialize in culturing and finding out "what type" of organism is causing it.
Every cow is different, there is no hard and fast rule. If she is a high cell count cow, her milk will not keep in the fridge as long. If her count is low, her milk has a longer "shelf life". Lower is better.