PH of milk is low

[nitai]

Hi everyone,

I am currently milking 3 Jerseys and have been for years. I make and store a lot of cheese but lately when it comes time to press my curds, I have noticed that they are melting, like they do when you make and stretch mozzarella. This means that the PH of the curds at that time has to be around 5.0-5.2 or so. This should not happen. For the cheeses I am making the PH should be closer to 5.9 or higher. So, as a result I tested the milk before I began the next batch of cheese and it was reading 6.45. Fresh milk should be around 6.7 PH.

I had our milk tested not long ago and Somatic Cell Count was a little high. But we just use the dairy for ourselves so I don't worry too much about that. Doubly confusing is that according to my research, a high SCC would increase the PH, not decrease it.

A few weeks ago one of our three Jerseys became very suddenly ill. She had diarrhea, gave no milk, and would not drink and did not get up. After 20 hours, right as the vet got here, she stood up and began to eat and drink as if all was normal. She has seemed completely fine since then and her milk production went back up to its previous place. For the past 1.5 weeks approximately this cow has been noticably more restless during the milking. She raises her hoof to kick (but doesn't) while I am cleaning her teat and she behaves somewhat abnormally while the milk machine is on her. She also for many weeks now does not finish her grains. It has seemed to me like one teat in particular disturbed her, but there is no visible damag to it and I have done a mastitis test with negative results.

I have a ton of milk and need to be able to make my aged cheeses but cannot figure out what could be causing the low PH. My vet is out of town for 6 more days, in which time I will need to process over 50 gallons of milk.

Any help is very much appreciated.

 

[regolith]

It would seem logical to do a pH test on each quarter of the cow you're concerned about. With such a small herd one cow/quarter will affect the whole lot.

It's possible for a cow to have mastitis and still pass the RMT and show no clinical signs. If you have a quarter milker, I'd be using it for the time being till you figure this out.
You know more about cheesemaking than I - could high bacteria levels cause the same issue as low pH?

 

[nitai]

Testing each quarter is a good idea. The odd thing is the milk has been tasting great and lasting long.

I had been assuming that high bacteria could cause the low PH, but that is not the case. The SCC count is a reflection of bacteria, but the higher the SCC (and the higher bacteria), the higher the PH. But I am getting low PH.

 

[TexasBred]

Testing each quarter is a good idea. The odd thing is the milk has been tasting great and lasting long.

I had been assuming that high bacteria could cause the low PH, but that is not the case. The SCC count is a reflection of bacteria, but the higher the SCC (and the higher bacteria), the higher the PH. But I am getting low PH.

SCC is NOT a an indicication of bacteria within your milking system and milk tank. You can have a relatviely low SCC and still have a high bacteria count. What is your feeding program for the cattle? These cows have at least subclinical acidosis and need more long stem fiber in the diet. Ideal grain:roughage content would be 40:60........50:50 will work but if you're grain intake is more than your roughage intake acidosis occurs. Butterfat probably is depressed somewhat and milk protein elevated....if milk protein exceeds milk butterfat content you definitely have severe acidosis which will also affect the milk Ph. Adding a buffer to the ration will help considerably if you don't presently have one. (Sodium Bicarbonate).

 

[nitai]

Thank you Texas, but in our tests the SCC is indicative of our overall bacteria count because we send samples that have gone through our entire regular workflow. Meaning they have been milked, filtered, bottled, and cooled with all the other milk. I do this intentionally in order to know the bacteria of what we are actually drinking, as opposed to just what comes out of the cow.

I have done some reading on acidosis, and while you know much more than I, no doubt, I do not think any of our cows have it. They are not exhibiting the symptoms except for one cow not quite finishing her grains each day. Our grain:roughage ratio is more around 15:85 or even less. These are our family cows and grains primarily function as something to keep them occupied while milking. Otherwise, these days they are eating all organic alfalfa hay because I have been unable to source grass hay, which I prefer to feed with the alfalfa. I do have grass coming in a few days now, though. While I have no ability to measure butterfat content, all three of the cows are giving pretty much the exact same amount of cream, and that amount is basically what it always has been.

I have developed one other theory about the low PH and will be testing that tomorrow.

Thank you for your time.

 

[nitai]

After some more research and additional PH tests, I am thinking I may want to feed some sodium bicarbonate in case there is acidosis. Can someone direct me to where to find the proper rations and so on. Is it a very delicate substance that I will need to measure carefully and prevent cows without acidosis from having access to?

 

[TexasBred]

Nitai all commercial dairies have daily samples pulled from their bulk tanks after having gone thru the entire milking system. I've seen dairies with extremely high SCC while also having almost NO bacteria count, becuase they did an extremely good job of keeping the entire milking system sanitized. Don't depend on SCC to indicate bacteria content nor vice versa...

You really need to find a lab that will also give you butterfat and protein levels as these can certainly indicate where you can and maybe should make improvements in your feeding programs etc. Those jerseys being fed a good balanced ration should be running close to 5% butterfat. The one that most likely has acidosis probably is running 3.5% or less. All of these things are good tools to not only help increase production but maintain herd health and increase your profits in the long run. The little extra $$ to test for BF and protein would pay for itself.

 

[alisonb]

Apart from your low PH concerns have you tried using Calcium Chloride in your cheese making process? I know the Calcium content in milk reduces when milk is pasteurized or the animal is sick or is in late lactation. A balanced amount of CaCl2 will prevent the Calcium from leeching from the curd - but you probably know this if you have been making cheese for a while

 

[nitai]

Thanks Alison, I do know about CaCl but actually completely forgot about it since I have never used store-bought milk and in the past my milk never needed it. I still have some in the fridge. Will have to see if it expires and consider using it. On the up side, even with the more acidic milk I have been able to make wonderful mozzarella, but there has just been sooo much of it!

 

[Nite Hawk]

High somatic cell count is not always caused by mastitis, although that is probably the most common reason. If a cow has an illness the body reacts by producing extra white blood cells which in turn raises her count both in the body and udder.
Some cattle when they have acidosis will instinctively not eat their grain.
( although some will eat until they die) and you mentioned your cow not finishing her grain.
Sounds like she is better after her sickness, but maybe not all the way well, I would keep an eye on her.
Exessive grain pushes the body towards the acid side, and can cause a tendency towards all sorts of health issues from hoof absesses to stomach problems, to mastitis, bad liver etc.
Also, different grains are "hotter" than other others--take barley versus oats.
I have seen animals get sick simply from a new batch of grain that has came in. They got a belly ache and the "runs" and went off their feed and were laying around. The older grain had had time to dry somewhat before being used, and the new grain was freshly ground an slightly "green".
Not saying this was the problem with your cow, and milk but it might be something to consider.
Nite Hawk