Here’s the place to ask your questions. We reply to every question or concern, so post here and we’ll reply as soon as possible!
1. A lady recently asked about preventing milk fever in her cows that are close to calving. She has had a history of milk fever in past years:
How does your cows’ manure look? I’m guessing kinda runny right now being out on spring pasture? If so, you should see if you can find some oat hay to feed them. This will help firm up the stool and slow down digestion. The grass runs through their system so quickly that instead of hydrating it actually sucks out moisture. So, keeping their stool firm (but not constipated) will help. If you have to, you might just need to lock them up at certain times to get them to eat the hay. Another plus to that is that cows like to eat grass, then lay and cud. Well, they smoosh down the grass and get holes going and you lose valuable pasture land. So, if you want to, you can start getting them tuned into a milking routine of coming in for a little grain (not sure how you’re set up, whether one or all at a time). Then you could come up with a pasture routine based on weather. If it’s going to be a really hot day, then keep them inside under shade during the day to eat hay and let them out all night to pasture in the cooler weather. If still cold at night, then lock them up then for their hay and pasture in daytime.
Have you had hay taken off your fields that could be tested for nutrient content? Or taken soil samples? Maybe your fields are somewhat out of balance, like high in potassium where you could add some supplements to balance out the pasture…
You might talk to your vet about adding some Vitamin D or B complex vitamins around the few days before and after calving.
At their production and ages, you shouldn’t be having too much problem with milk fever…. There are a few things you can do to help around calving time.
1. Make sure they’re not fat or thin
2. You can give a preventative calcium or CMPK paste just before or after calving. CMPK is preferable, because often a cow has an imbalance in more than one area, so the combination covers the most important ones.
3. If the cow does come down with milk fever, treat ASAP! We IV a bottle of CMPK and a bottle of Dextrose into the cow. Dextrose is just sugar water to give her a little boost. If she is dehydrated, then you can also IV a saline solution. This will get her wanting to drink. The worst thing you can do is let a cow get dehydrated and have her system shut down. She should shiver while you are giving the IV, it indicates that everything is working. Afterwards, she should pee fairly soon. That’s a good sign also. If she’s thirsty, you can try your water trough or you can bring lukewarm water to her in a bucket. If you give saline, she’s going to want that right away. If she is down, you’d also like to see her get up soon after treatment.
4. If she is still slacking, then re-treat her. I’ve seen my husband treat cows only hours after a first treatment if they’re really sick. His attitude is that an aggressive (“proactive”) treatment is much more likely to get a cow better quickly.
I don’t think I’ve ever seen a cow come down with milk fever that my husband couldn’t treat. We rarely lost a cow, because of his management. I say this to encourage you that if you try adjusting some feed/mineral rations and keep vigilant about monitoring the cows’ health, you should see a definite improvement.
2. A lady recently purchased a Jersey cow, only to find out the cow has had no training and is due to calve soon:
1. Horns must go. Yes, God made Jerseys with horns, and original cows were wild. He said to have dominion over animals, so we domesticated them and part of that is by dehorning. Losing your life for milk is just not worth it. Consider buying polled semen for your future breedings if you don’t want to deal with horns.
2. Do not allow her to push you! Whatever it takes, do not let her be boss. She’s probably lonely and adjusting to a new place by trying to be “boss cow” and because you’re smaller, she’s winning. Their ears are sensitive, you can flick their ears with your hand for more impact. Another thought is to carry a rope with you and snap it at her if she comes at you agressively.
3. I am guessing this Amish farm did not halter train this cow? One thing you can and should do is get some treats, such as grain, to start feeding her. Get your stanchion for milking built ASAP and start NOW feeding her in there twice a day. While she is locked up, start petting her all over. Massage her udder with lotion as the swelling increases (closer to calving).Gently rub and squeeze her teats (not too much, you don’t want to let out the natural plug in the teat end, but you want her familar with you touching her there) This will help her get more comfortable with you touching her, and when she is in milk, you will be very thankful for the time spent beforehand! You should have a halter on her, at least until she starts obeying you consistently. You can get a rope halter with lead (they’re very cheap, about $4 at feed stores and are adjustable). Then when she is locked up one time, put the halter on her. You can let her out and leave the halter/lead on her. One, you’ll be able to catch her more quickly and correct bad behavior. Two, she will drag the lead around and learn about having something pull on her face. Once she is somewhat settled with the halter, tie her closely to a very secure, firm post or wall. She may fuss for a while, but leave her tied there. After one or two days, she should be comfortable with the halter. You can decide to keep her on a few hours and let her go or you can just leave her tied and bring her food, water, and bedding.
4. To catch her: First, tie up your horse and lock up all the animals you can. They do not need to be added distractions while you’re catching a wild cow. Do you have a trailer, round pen, stall, anything enclosed to catch her in? Corner her in one of those areas with at least one or two other people helping you. You can throw a rope around her neck initially, then try to get a halter on her head. If you really have to, maybe your husband can grab her by the nose. Pinch hard like you are a nose ring, fingers in each nostril. Then lift up her head and the other person can try to slip the halter on. I know I am sounding agressive, and trust me, I don’t like to be, but if this cow is wild and calving in 1 month, you need to get control as soon as you can. Once you get her on a halter and tied, your biggest step is over. In the future, if you have a heifer calf, be sure to put her on a halter at a young age, around 1-3 months old. They’re very easy to handle and the sooner they learn, the easier it is.
5. Milk pumps – They are very expensive. You can check out craigslist or call neighboring dairies or look in your local papers. But, used are very hard to come by. You can build one if you have the know-how. Otherwise, check out http://familycow.proboards.com/index.cgi
and post that you are looking for a new or use milk pump for your machine. Scroll down to “The Family Cow” and post there initially. They may move it, but you’ll get tons of people looking and helping you. Fyi, price for a new pump ranges $800-1200. I can get a brand new stainless steel pump for $900 from the Amish here. Used, I once found one for $150, but I’ve never seen one that cheap again. My friend got a pump and milker for $800 off ebay, a rebuilt unit. Might check into that. Be sure to get one tho, because dairy cows are NOT modernly bred to be hand milked. Often they have little tiny teats.
Well, I hope that’s not too overwhelming to start with. I’m sure there’s more to talk about, but I need to get back to work. Let me know if you have more questions and update us all on how your cow is doing.
3. A family was looking for an “all-in-all” reference book about family milk cows:
Sorry, that book does not exist!
You can search online for books. I borrowed some through the library first to see if I wanted to purchase any of them. I never did, but rather wrote down a few notes from the books that I wanted to keep on hand.
Joann Grohman’s book “Keeping a Family Cow” is an informative start for those new to the dairy industry.
I would also recommend looking online.
Magazines Progressive Dairyman or Hoard’s Dairyman can answer some your questions, even though they’re intended for larger farms.
4. What is causing that off flavor in milk? Is it the wild onions?
Onions and garlic are notorious for off flavors. I have heard that if they eat them, the taste will be gone after a few hours. So, where you get your milk, say they milk at 7pm. You could talk to them about locking up the cows around 4pm, feeding them some hay, and letting it wash out of their system before milking time. Then let them outside again after morning milking.
One experience I had with off flavors was in the spring, the cows eating a weed called Pennycress. Your milk tastes bad, even though it is fresh!
5. A person got bit by a tick, wondered about Lyme’s disease, and then wondered if cows get tick-borne disease?
Keep an eye on the spot where the tick was. If you get a bullseye, head to your dr asap. Might not hurt to get checked for lymes, too..For cows, I got to researching and remembered when we moved our cows to PA, one thing we had to test for was anaplasma. It’s a tick-borne disease for dairy cattle. Because of insecticides (is that the right word? Anyway, whatever chemicals they use to kill ticks).. ticks are resistant to many chemicals now, and are increasing. In Maryland, the incidences of tick-borne diseases has skyrocketed!! Anyway…I was going to add some info, but if you’re really curious, just read this link: http://veterinarynews.dvm360.com/dvm/Vet…./d etail/501075
QUOTE: ” In non-endemic areas, the goal is to prevent the disease from coming into a herd. Herd additions should be screened with the cELISA or purchased from test-negative herds. Because of the potential for possible false negatives on the cELISA during the incubation phase and the potential for wildlife reservoirs, the disease still can sneak in. Therefore, a new needle should be used for all animals and equipment should be washed/disinfected between animals.If available, vaccination, especially of the most valuable animals, should also be considered. The only vaccine available is produced by University Products and is offered in 14 states via a U.S. Department of Agriculture experimental approval. However, work is ongoing to allow availability nationwide. Visit www.anaplasmosis.com
for more information about the vaccine. “ 6. About a new cow and adapting to a new environment:
Getting a cow mid-lactation like you did and all the changes… You might not get much milk the rest of the lactation. Some cows just take change a lot harder than others. If she is bred, too, then she’s naturally going to decrease production.How tall is your grass? Cows are picky and they like nice tender stuff. If you have a mower (on highest setting) or even better a brush hog, you can “clip” the fields/pasture occasionally to keep the grass growing and nice, soft, appealing for the cow. Your pastures will last a lot longer if you clip them, so that’s always helpful.Someone already mentioned soaking your alfalfa pellets or buying hay. If you cannot find good alfalfa hay, then I’d agree to soak them. The cow should like them, or you could add some grain or molasses to “sweeten” the mixture to appeal to her. I like beet pulp too. You might consider a mixture of the two (beet pulp = healthy rumen and glossy coat.) My first cows were very grain-fed, so I had to just put grain on top of soaked beet pulp and let them very slowly adjust (like, over half the lactation to get them excited about beet pulp).If your cow is not enjoying her hay, then cows can get real picky and stubborn and even starve rather than eat a bad bale. You may not see why, but she senses something bitter or wrong. It’s a good lesson in buying one bale to test out on her before buying tons of hay!! Remedy is to just find different hay for her.With all the stress of moving, changing owners/handlers, new feeds, new environment… Don’t expect much milk and don’t expect her to gain much weight. If she’s letting down well and seems content, then you should be able to stabilize production. But your real goal is to just slowly improve condition (and I mean from now until Thanksgiving!! Takes time!) until you get her just a tad chunky, then calve her in and milk that off and you should be good to go condition-wise!
7. Why do I need to dry off my cow?
Drying off is NOT just about colostrum! Cows require 60 days to relax, take a break. They need time to build back up their strength, body fat, minerals, etc. Plus, the last month or two are when the calf inside her is growing the most. She needs all her strength to calve and have a healthy lactation. If you never dry her off, it will affect greatly her next lactation and can lead to reproductive problems and all sorts of other issues. Powdered colostrum is for the rare chance that a calf cannot get colostrum for the mother. Powdered colostrum/milk should be a worst case scenario last resort.Can you milk through? Yeah. Should you? No!In all the cows I’ve worked with, we’ve never had a cow refuse to dry off. Operator (people) error is more the issue.
8. What kind of a dairy cow should I look for if I want to keep her on mostly a pasture diet?
First, you need to look for genetics that can support an all-grass diet. Any protein breed will be superior than Holsteins in efficiency of pasture grazing. Beyond them, you can look into other dual-purpose breeds for increase efficiency, but much lower milk production.I would agree with you that regardless of operation, a good udder is a good udder. For a cow outside, you might want to be extra careful to get a very well attached udder to lessen chances of sunburn. So, a high, wide rear udder and well attached fore udder are good. Plus, if there’s brush and whatnot, a high udder would be less likely to be scraped, poked, etc.I would also agree that in general, a smaller animal (Jersey/Milking Shorthorn/Dexter/etc) would be easier on pasture.I know of many bulls that produce “stockier” type Jerseys, so a few of mine are definitely ones that need to be on a grass diet. They tend to be shorter, wide, high tight udders, and a tendency to get fat.One note, on grass, just about any dairy cow is going to be thinner looking. Grass tends to keep a cow looking dairy and milky without putting on that chunky weight.
You can look for a few bulls (I mean, more likely their offspring) that will reduce stature or give you a smaller Jersey: Dusaiseoir, Centurion, Golden Boy, Simba’s Pride, Remake. They should all give you gorgeous udders and smaller stature. Plus, they tend to be bulls that aren’t overly plus on milk (except Centurion) so they do well as family cows and are heartier.
9. I’ve been told Udder Comfort is a good lotion to use on cows:
Udder comfort is a very expensive name-brand cream that has peppermint and tea tree oil. Funny most natural methods commercial farmers aren’t interested in, but they branded it in a way that they will use it. LOLYou can make your own at home from a lotion base of any kind and add peppermint and tea tree oil. Or you could just mix them with some oil. I make it strong enough that I can feel it tingle on my skin. That way you know the peppermint is taking effect. Tea tree oil is antimicrobial, so very good on an udder too. My cows did well with the homemade version.10. I want to give my cow Dexamethasone so her swelling goes down:
Dexamethasone can cause dehydration and cause a cow to stop eating. Many people do not realize that you can use less than the recommended levels for just as good of results. My husband Jay likes to use a lesser amount, and then over a 3 day period if he does use it. Dex. is used for aborting calves, so you have to be careful of unintended consequences of use. Again, this is all mostly if you are using too much. It can stop liver functions. He says it’s like wringing them out, sucking out the edema but also dehydrating them. The difference between dex and banamine is that dex does not make a cow thirsty, but banamine gives the cow a good feeling so she wants to drink.My opinion is to just not use any drugs unless really necessary. Occasionally, a cow may have a bad calving and get swelling all over, and so some cases do benefit from dexamethazone. It’s just good to be cautious. People see good results, so they might not be so careful about dosage.Any anti-inflammatory type medicine inhibits healing. For simple udder edema, there are any natural methods, and time, that any cow on a healthy diet will respond to.
11. Edema causes mastitis, right? My vet gave me banamine to treat it.
All cows get edema, it’s just one of those things in life. It doesn’t mean she is definitely going to get mastitis, I promise. Banamine won’t do much except make her a little happier, temporarily. Some cows take up to a month or more to lose all their edema. It’s more important to have a sanitary milking routine and clean bedding and feed management. Even if you think it’s doing no good, get some cream and massage the udder all over, especially the cleft. The stiffness of the teats at first can prevent the teat ends from closing properly, so having a post dip and practicing good management (such as keeping the cow up and eating for a half hour after milking) will help the teat ends close up before the cow chooses to lay down.
12. My cow has mastitis for sure. I want to get the milk checked, but what should I test for?
Because you already know you have mastitis, the bacterial culture is more important to see WHY.Then, Somatic cell is nice to do over and over to check the health of the milk. Checking somatic cell when you know you have mastitis might give you a minor heart attack.
13. We bought a dairy cow and she’s really thin!
It could be that coming from horses the cow looks very skinny to you and maybe she’s just a busy cow in milk? People always see certain breeds of dogs, like hounds, and think, “Your dog is way too skinny” when they just naturally look kinda thin, mostly because they have such a thin hair coat. (See: Body Condition section of our website for more information on evaluating your cow.)14. If my cow gets mastitis, is that it, is she ruined?
We’ve had mastitis of many different types and from many different cows. Almost all of them can successfully be treated within a few days IF you catch and treat as soon as it shows up. Those cows can come back to 75 percent production or more in subsequent lactations. And it’s healthy milk too, cultures can show low SCC and no “bad” bacteria.Penicillin gets a bad name because it is misused quite frequently. Only a milk culture will be able to tell you which antibiotic to use, if you go that route.My opinion is that vitamins, minerals, etc are all important PREVENTATIVE measures… For full blown mastitis, as everyone says, step one is a culture. Step two can be decided by what comes back in the results. If mild, then mild measures can be taken. If severe, antibiotics must at least be considered.Bedding issues are a major source of bacteria. A lot of people like their cows to be outside, but being in wet or muddy or dirty areas equals mastitis potential. Always have a nice, dry, clean area for your cow to sleep in or be locked into in bad weather. IF you are going to have your cow outside, she needs nice grassy areas to lay in. Or bare minimum, a very dry area to lay on.
15. There’s some kind of clear slick coming out of my cow’s rear end. Does that mean she’s calving now?
Mucous just means she’s doing the right things.Could mean a week or two away. Watch for if she’s acting strange, sticking her tail straight out, wanting to go far away from everyone. If the teats are full and glossy, or even spraying milk, that could mean she’s close.16. I want to trim my cow’s hooves, but she won’t let me touch them. Can I tie them down?
I’d be very careful with any restraints or force. Scaring a cow might just make her permanantly scared. Is she okay with her front feet being done? At first, just do fronts and get her very comfortable there.When she is good there, then you can chisel around the back toes WITHOUT picking up the hoof. Most cows don’t want their back feet picked up. I just turn into a neat freak and want the bottoms nice and clean and trimmed, so after a while we try to get the cows to pick up their back feet. But it’s definitely a slow process.
You can angle the chisel to try and get a bit underneath the hoof. It’s not the most ideal situation, but keeping the worst of the tips trimmed off is better than nothing and eventually, working with her, she should allow you to pick up her feet.Or you can try to trim when she’s napping laying down.17. When should I cut off extra teats?
You should check a heifer at a young age (3-6 mo) to see if she has any extra teats. If you know what you are looking for and see an extra teat, you can use a sterilized clean curved surgical scissor and snip off the extra teat. It’s a similar concept to using a gouge to dehorn. The curve of the scissors clips just under skin level to take off the whole teat so it will seal up and heal over. If you catch them at that age, the cut should heal up very quickly and never cause you a problem.
18. If I had a cow with BLV, can another cow get it even if the infected cow is long gone?
I compared BLV to HIV. First, some people get HIV and never AIDS. Second, think of how HIV/AIDS is transmitted – through blood. So, occasionally a calf can get it inside the mother. It helps me to think of HIV as a comparison.I’d recommend anyone purchasing a cow to have thorough testing done beforehand. “Cheap insurance” It puts everyone on a level field of honesty and then if the cow comes up positive for something 6 months later, you know you all did the best you could to get a healthy cow and that’s life.Buying a lot of cows from different places can bring in all sorts of problems. I see you have multiple animals, and that can be a consequence of “buying around”. As close as you can get to a closed herd (meaning no buying of animals from different farms) the more protected you will be against new diseases. Staph Aureus is a terrible plague at a farm I know. They sold off all but about 15 older cows and then calved in 40 young cows. Guess what? Those young cows are coming in with huge staph counts.
19. My cow won’t let down her milk for me, only her calf.
If you are wanting to not keep her with the calf, you can give her 1/4 cc (.25 in a tiny diabetic needle) of oxytocin in the milk vein OR 2cc (regular needle) IM at milking time. This is the natural hormone that a cow uses to let down her milk. You’re just making the decision for her. It works well for the few milkings you’ll need it until she starts to forget about the calf.If you fight her for long, you may end up seriously affecting her milk production for the year.Also, you can massage the udder, especially high up on the rear udder and all the way down in a soothing motion.
20. I’m having a hard time finding alfalfa hay for my cow. Any tips?
1. Have you looked up a hay directory? Or just drove around? We had to search high and low to find our hay, but we are so blessed to have a barn full of hay this winter and a great supplier now. Took a while to find him! We pay $5/bale for maybe 30-40 pound bales. So, lets say $250/ton. My friend in Howard Co., MD pays more than me, from $250-500/ton. (My dad pays $110 a ton for good hay, see why we’re moving home next year!!)
2. Alfalfa mixed with grass is your best bet for overall “value” due to palatability and digestibility. So, try to find that. Be willing to pay more for HAY instead of alfalfa pellets or beet pulp, because a cow needs LONG-STEMMED fiber. I’m not trying to yell, just highlighting the most important points. Fiber = rumen = milk!!!
3. I would pay a lot more for good hay than even for grain. Grain bill high? Cut back and go buy some good hay. LOL Am I getting repetitive?!
4. If you know you need a lot of hay and somehow you can get the money, consider getting a trailer of hay. And I mean semi-trailer of hay. If you can’t get it locally, you’ll have to look further. So you may be getting enough tonnage to last you 2-3 years, but if you can store it securely, you’ll probably get a much better rate than from a store (that’s probably where they’re getting it anyway!) and you’ll know you have hay.
5. Consider that semi-trailer, but then re-sell hay to your neighbors for a higher price. They’re probably begging for hay too, and then you could use up the trailer much quicker. When straw prices got silly for a while in Washington (using it all for construction of a major road, so price jumped to $11/bale!!!) someone drove to LaGrande, Oregon and filled a pickup truck and huge trailer with straw. Sold it to us for something like $5/bale and he’d paid $2. Wow, we all benefitted! I know a lady in Buckingham, VA (45 min. south of Charlottesville) that would LOVE to buy some alfalfa from you if you got it. Her Guernsey is in desperate need of some good hay, as she’s just fresh!
6. If you buy a whole load, it’ll probably already be tested. You can look up “forage testing” online to check the numbers, or feel free to email me and I can help explain them.
7. If you buy a smaller load, ask to take ONE bale home that represents the load pretty well. Feed it to your cow. If she hogs it down, buy as much as you can. If she spits it out of her mouth, say “No thanks.”
8. Breed your cow to Canadian bulls that decrease production. This will help create offspring that will “take care of themselves” meaning they won’t demand so much input for output. You’ll cut your hay bill without losing much production.
9. Keep watchin craigslist and other hay dealer sites for new postings. Now is the time to buy (well, ideally is “just out of the field in July” but now is much better as they still have a lot of stock. Come spring, you’ll really be paying a lot!)
21. Do I have to feed my cow year-round?
You can plan on feeding a dairy cow hay year round. Grain can be minimal, but so far I have not seen much success not feeding any grain (they need some, at least while they are in the first months of lactation. All dairy cows go through some negative energy balance near calving, so the grain is important for an energy source.) If you have ideal plush pastures, yes, you can cut down on your hay bill drastically. Cows are more efficient converters of milk (for what you have to feed them to what you get back in milk) than goats, but goats work better for so many people because they don’t need 5 gallons a day OR they are limited on space. And I believe goats eat grass too. Our friend have all goats and they hand-chop all their hay (like the olden days!) and that hay is just pasture grasses.
The term “grass fed” applies to BEEF not DAIRY. Beef, we raise our steers 6-8 months on milk (no grain necessary if they get good raw milk from their mom. We bottle/bucket feed to the calf, separated from cow.) From there, they can live on pasture and hay (Ours are on pasture only all summer, but like I said, we have lots of good pasture, so they always have enough feed. Come September, they are usually supplemented with 50% hay and October – April, a hay diet.)
The confusion on grass fed is complex…. “What is grass” and all that nonsense. Basically, a beef animal is eating for MAINTAINENCE and GROWTH. Maintainence requires very little nutrients. Growth requires good quality hay, but still a moderate nutritional need. A dairy animal is eating for Maintainance, Growth of a baby (9 of the 12 months each year), and LACTATION. Lactating is the most nutrient demanding function an animal can have. This is why a cow requires excellent hay and a bit of grain. So, even when the cow is not lactating, it means she is likely in the last stages of pregnancy, in which the baby grows the most. You just can’t get around those nutritional needs!
22. What exactly is grass-fed? Most people that say they are feeding their cows “grass fed” are feeding a lot more than just grass!
Yes, “grass fed” is about as mis-used as the word “organic”! True grass fed would mean the cow would be on only pasture or grass hays. Not even alfalfa!Some include silage because they say “Well, corn is a grass”… Well, the stalk may be, but the corn itself is a grain. Most “grass-fed” people seem to feed alfalfa, which is a legume.We just say we feed what the cow needs to be healthy and productive. That may include grains (soaked, sprouted, cracked, etc.); vegetables (beets, etc.); legumes (alfalfa, clover, etc.); molasses; minerals/clays/etc.; grasses and I’m sure some types of weeds or herbs; and as much sunshine as we can get them! We don’t have a need to “label” what we feed our cows. We just try to do the best we can!
23. When I first start milking my cow, her teats are nice and round and full. After just a few squirts, her teats have gone soft and feel empty. I can still get milk from her but it seems I’m working very hard for every little bit. Is this normal or is it her holding up?
Hmm, sounds like she’s NOT letting down for you.For our cows, we go through a “letdown” process, which involves turning on the milk pump, dipping the teats, letting that soak for 30 seconds, wiping the teats, squirting once from each teat, and then we put the machine on. There are lots of variations to that process, that’s just how we do it.
And I can definitely feel from when she first comes in (touch her udder then) to when we’re ready to put the machine on (touch the udder again)…She feels like she’s real heavy in the bottom part of her udder, her udder might even go pear shaped because her milk is letting down, literally.
On a side note, I was reading in Hoards Dairyman about milk quality and low somatic cell and a bunch of farmers do their dipping and pre-milking in different patterns, so I thought “I’ll pre-milk and THEN dip, like some of them do” so I walked up to my cow and pulled on a teat…nothin! So I just went back to my other routine (mentioned above) and by the time I’ve wiped and massaged, she’s let down her milk, so I pre-milk then, and we’re good enough!
24. My milk is foamy when I strain it. Should I be concerned?
Here’s some information from Bernard W. Hammer (1946) Dairy Bacteriology. New York: John Wiley and Sons, 46-54.
“The organisms of most importance in producing gas in dairy products include (1) certain non-spore-forming yeasts that ferment lactose, (2) the Escherichia-Aerobacter group, and (3) certain organisms of the genus Clostridium.
Sanitation will be most important, to avoid growth of these bacteria. If they aren’t there, they won’t cause the foam. Make sure and read up on how dairy equipment should be cleaned and sanitized. Also important: cool the milk quickly to avoid growth of whatever is causing the foam.
Yeasts can be a problem because “they interfere with the normal churning when cream is held for several days, as is done in home buttermaking.” Yeasts are acid tolerant, which is how they show up in products like sour cream and other milk products.
“Without coagulation there is little tendency for the gas to be held and it readily escapes.” So basically, if you cool your milk quickly and just use it as straight milk, the yeast should not be a problem. The problem comes when you start to use the milk for products like butter or cream, where the gas cannot escape as well. Occasionally, I think this can be a problem in cheese as well.
If it’s not yeast, it might be E. coli or A. aerogenes, and can be eliminated through sanitation measures at milking time. (Rarely, comes directly from cow. The book says primarily contamination causes it). These bacteria are less foamy and stinky than yeasts. If you shake the milk, it may foam up if you have enough of these bacteria. They also create “objectionable flavor” which is probably your biggest concern, along with more rapid deterioration of the quality of milk (doesn’t taste good as long).
Clostridium bacteria are not of concern if you are keeping the milk raw, as they don’t survive over the good bacteria. Your only concern, then, is if you improperly pasteurize the milk, they can have room to replicate then.