Awhile back the FDA raised the maximum number of somatic cells that Grade A goat milk can contain from the former limit of 1,000,000 to 1,500,000. Our state (Oregon) followed suit just this year and adopted the new limit for goat milk and also lowered the cow level from the FDA level of 750,000 to 500,000. While I applaud the cow levels, I am concerned about the goat levels.
Just what are somatic cells and why do they matter?
I have read and heard somatic cells in milk referred to as “pus”. This is not correct! Somatic cells (SC), by simple definition, are “body” cells. In milk, these can be normal skin cells (epithelial) shed by the milk ducts (more on that in a bit), portions of the cells (cytoplasmic particles), or white blood cells (leukocytes) that are present in order to fight off an udder infection (white blood cells are also present in “pus”). So let’s talk about why a healthy udder matters and the difference between the epithelial and white blood cells.
First, udder health correlates with the animal’s health and wellbeing. If you believe in the humane treatment of animals, then this should be important! Second, milk produced by a less than vibrantly functioning udder will not be of superior quality – either for drinking or making cheese. A healthy udder is created and maintained by a nutritionally, physically, and emotionally balanced animal. (Yes, they do have emotional needs!). While I won’t be covering all of these needs here, it is important that you remember that they are the foundation for the production of superior milk).
White blood cells migrate into the udder in order to fight off microorganisms that could cause, or are causing, an udder infection – the same job they do throughout our own bodies. When they are called to the battle front within the udder their presence is indicative of a problem. The problem could be unseen, meaning you can’t see any difference in the milk or the udder – no swelling, heat, clumps in the milk, etc. This is called “sub-clinical” mastitis and is the most common form of mastitis (udder infection). When a severe udder infection is present, it is called “acute”. Animals can suffer greatly from an acute case of mastitis – including loss of the affected part of the udder to gangrene or even death.
How Cow’s and Goat’s Differ
Now, let’s go over one of the unseen differences between goat and cow milk. Understanding starts with remembering that the udder is a gland. The mammary gland, to be exact. All glands (we have lots of them – from our armpits to our stomach) secrete their products in one of three ways. Two of these are pertinent to milk secretion – apocrine and merocrine. I am not telling you this to add more words to your Scrabble game, but instead to explain some very important differences between cow and goat milk. Glands that secrete via the apocrine system also shed parts of the cell wall lining. Goats and humans secrete milk via the apocrine approach, while cows milk is shed via the merocrine system which keeps the secretory cell intact. Kind of cool, kind of gross, don’t you think? From this you can rightly conclude that goat milk will have a “naturally” higher somatic cell count (SCC) than cow milk (when cells are counted using the same method traditionally used on cow milk).
What is a Normal, Healthy Somatic Cell Level in Goat Milk?
So if goats naturally have a higher SCC, why am I concerned about the legal limit being raised? In my experience, which is not all encompassing of course, a SCC over 300,000 in our goats, means there is a very low-grade problem. How do I know this? Every month a person comes to our farm and collects a milk sample from each individual milking doe. This sample is then tested at a certified laboratory for many things, including SCC. If the count comes back over 300,00 then we march out to the parlor (as we already do twice daily) and do a California Mastitis Test (CMT) on that doe. The CMT will show the difference in SCC between each half of the udder (or each quarter if you are testing a cow). If they are different, then It is not normal, one side has a problem. By following this policy we have (knock-on-wood) never had an acute case of mastitis and or current herd average (from tests covering about 10 years) SCC is 104,000.
Note: SCC are usually read MINUS three zeros. So 162,000 will appear on test results as 162. Anything below 1,000 is usually not counted and will appear as zero.
I have always wondered if perhaps Nigerian Dwarf goats, our breed, have a lower average than the big girls. We have two full sized goats, LaMancha’s. Their average SCC are 109-125,000 (higher than our total herd average). The current average of all dairy goats in the states covered by our testing association is 625,000. When looking at the 2011 summary, where the data is analyzed from several standpoints, Nigerian herds average 121,000 while standard goats average 783,000. If looked at by milk production volume, does producing about 3,000 pounds of milk or more are the highest at 939,000. Herd size (meaning if you have only a couple of goats versus 31 or more) seems to matter as well, but not as much as milk production volume. So many factors may come into play, but I still have to wonder if this higher limit won’t have the unhelpful effect of causing some producers to ignore even more subclinical mastitis cases instead of jumping on top of the situation before it gets out of hand. Having known commercial producers who have gone from high counts to low by improving techniques and removing animals with chronic subclinical cases does make me feel that the higher limit is a mistake.
What can You Do to Monitor Your Animals and Treat High SCC’s ?
If you have goats or cows and are not on a program where their milk is regularly tested, I highly advise performing a CMT (or other SCC’ing test) EVERY MONTH. By doing this you will find little problems and be able to address them before antibiotics are needed)
So what do we do when one side of the udder has an obvious (decide through CMT) problem? First you must rule out problems with milking equipment and general health of the animal. Of course, when it is just on one side, then you have to assume an udder infection of some sort. Before you resort to antibiotic usage, you can try some organic and old fashioned remedies. I used to do peppermint oil rubs to the udder and give the doe an oral dose (about 60 ml) of her own milk – to hopefully stimulate an antibody response. I
have recently added a common certified organic producer’s technique of orally dosing the animal with garlic “tea”. What a miracle it has been! We soaked peeled garlic cloves in water (be sure to keep refrigerated as botulism is a risk if not) then dosed the doe with 40-60ml 3x a day and her SCC went from 722,000 and 652,000 on the next test (the CMT showed a problem on one side) to, are you ready? One thousand. Yup. Garlic. Thank you!
Some animals have chronic infections that even garlic cannot clear up. A milk sample should be sent to a certified lab for culture and if appropriate antibiotic therapy can be used. There are some dairy animals now, though, carrying the antibiotic resistant form of Staph aureus (Methicillin-resistant Staphylococcus aureus) these animals should, unfortunately, be culled – removed permanently (not simply passed to another herd!)
So no matter how you feel about the new SCC limit, I hope you will take your animal’s welfare and the quality of your milk so seriously that you will set your own standards. Try to not accept less than the best – no matter what the regulations say!