So I'm excited to talk to you about sort of a crash course in bovine nursing. Sort of cows 101 for folks that don't do a lot of work with cows. So we're going to cover a lot of information, Dr. Steve just gave a great introduction, but just for my own personal street cred with you all, I did sometimes handle small animals, mostly in the way of kittens that we would neuter/vaccinate on the back of the truck. And sometimes I had a few farmer clients that bred, bred dogs. And so I got to play with puppies sometimes, too. So didn't always just handle big, huge animals. This this girl right here, her name is Winnipeg. She was a free marten, which means that she was born co-twin with a male and so was reproductively sterile. And she was a pet and she was 16 years old in this picture. Her owner threw her a sweet 16 party, complete with a tiara and tutu. And I'm sorry, I don't have pictures of that.

So let's dive right in. The first thing that we're going to hit here is just some key anatomy and physiology to review how cows are different than other species of animals. And then we'll talk about the things that go wrong with them. Cows are incredibly hardy critters, which is why I loved working with them. And they are also prey species. So we have to remember that they're going to hide signs of illness whenever possible because they don't want the lions on the tundra to eat them. So we'll talk about some key diseases for you to kind of have in the back of your head.

First, however, again, just dialing back a little bit we're, I wanted to make sure that we are very clear about types of cattle. So dairy cattle are very different than beef cattle. And if this is super redundant or a review for you, I apologize. But they, despite the fact that they are both bovines, they're very different animals. It would be like the difference between a Chihuahua and a Rottweiler, perhaps. Very different animals that you have to handle very differently. Dairy cows are bred for milk production. Their job is to produce milk for human consumption. They are housed in barns for the most part. There are grazing systems, especially in other parts of the world, where there's access to grass more frequently than there is in, say, Maine or New York, where we're under snow for a lot of the year. And most importantly, these animals are handled every single day by humans. They're moved into milking parlors to be milked. They are their barns are cleaned every day. They're very accustomed to humans around them. Their breeds are long-legged and big-bodied, so they tend to be a bit taller than beef cows. And their bodies are a bit deeper. So this is a Holstein cow at the UNH barn, and you can see that she is not afraid of me. She is very curious about what I'm doing and sticking my phone in her face. And so that's very typical of the behavior of a dairy cow. Beef cows, on the other hand, have been developed, the breeds that we use for beef production have evolved in a very different sort of production environment and for very different production purposes. So beef cows, or beef cattle, are raised for meat production. And so in the beef world, there are cows and calves. So here you can see a black angus cow and her calf in a pasture. Their typically, cow/calf operations are typically on pasture with run-in sheds, so not like full-on barns, but just three-sided shelters for them to get out of the elements from time to time. And then at a certain point in time, these calves will be sold to a feedlot where they will be raised to maturity for beef production, and that is also outdoors. And so these animals are handled much less frequently than dairy cows. And so you can see just the attitude of this lovely beef cow here. She was suspicious. So we have a curious dairy cow and we have this black angus who's looking at me like, what are you doing? Why are you in my pasture? And so that is going to influence, if you will, how we handle these guys and what sort of restraint we need when working with them. They tend to be a little bit shorter stature. The legs on a beef breed tend to be a little bit stubbier and a little bit rounder bodies because we're not breeding them for milk production, we're breeding them to produce a calf every year.

So some landmarks. Some landmarks that are important to know when you're working with cattle. And a lot of these are similar to probably if you attended the equine lecture, very similar terms that you're probably familiar with. So the Withers is just the point of the, right about, dorsal to the point of the shoulder here. The poll of the cows head is this bony protuberance on just dorsal to the sort of forehead area. And I will tell you from personal experience that there is nothing more dangerous on the cow than her poll. It's not necessarily her feet. Feet and legs I can sort of manage, but the poll of a cow is very, very dangerous to you. And so you always want to be careful when you're working around the head of a cow. In our dairy cows, the mammary gland is the key sort of production unit on the cow and it's huge. We have bred dairy breeds to produce high volumes of milk and so the organ has evolved appropriately. The udder on a beef cow is going to be much less visible, so to speak. It'll be tighter up to the body wall because that beef animal only has to feed her calf. Whereas we're asking dairy cows to feed us humans. In order to produce this milk, we have to have huge volumes of blood supply to the udder or the mammary gland. And this vessel right here, this is actually a blood vessel. This is the mammary vein or the milk vein. So this is venous blood draining from the udder back to the heart, which is up here at the point of the shoulder. And you can see how big this sucker is and how really external to the body it is. Really right there on the flank of the cow, covered by skin, essentially. And so one of the things that can happen is that this vein can rupture and that would require immediate intervention prior to death. Hocks are hocks. You guys should be familiar with the word hock, but that's the hock on this guy and something that we pay attention to for safety reasons. And then the pelvis of the cow. We give this colloquial to terms, to, we call it, we talk about hooks and pins. Pins are back here. I have another image of that and just a second. But they're just good landmarks. This is just the the the cranial most point of the pelvis and the caudal most point of the pelvis, but it's a really good landmark for some things that we care about inside the cow.

Some other external landmarks for you. So the paralumbar fossa. Is this triangle made by the, the distal aspect of the transverse vertebrae up here, the last ridge or rib excuse me, the caudal aspect of the last rib, and then the hook, which you can see here. So this triangle here is a really important landmark because it's one of the places that we can auscult, or listen to, the digestive tract of the cow. So on the left side, we're going to listen to the rumen here. On the right side, we can listen to the cecum and the small intestines and we'll talk a little bit more about that later. Paralumbar fossa is a really important landmark here. Here is another image of the hook right here, and I promised another point of the pin, these back here are the pins. And there's another hock, which, you know, we have to be a little bit cautious of. Cows are less athletic kickers than horses, so they can kick you. However, they tend to kick out to the side rather than straight back double barrel style like an equine species might, breed, might. And so when we do anything with cattle, it's actually the best advice is to stay as close to the cow as possible, because that will ensure that if she does kick you, she doesn't have a whole lot of room to get up momentum to kick you hard. The closer you are, the less impact those those feet can have.

So other things that are interesting and different about cows. Their digestive tract is definitely high on that list. So cattle have are are are ruminants. And what that means is that their digestive tract, the forestomach of their digestive tract, is uniquely evolved to digest cellulose in plant matter that you and I can't digest. In order to do that, the forestomach, it has four compartments. And we talk about them sort of in an order, but it's a little a little fuzzier than that. The esophagus comes down into the reticulum, which is the first compartment, and then the feed stuff will go into the rumen. The rumen is about 40 gallons big. So like one of those big, huge trash cans on a farm or anywhere, about that big. So huge vats where fermentation happens. So feed stuff in the rumen, there's three layers, there's a gas cap on top, there's a fiber mat of larger particles and then there's fluid down below. And inside this fluid, there is a diverse and massive microbial population of bacteria, protozoa, fungus. And these microorganisms actually digest the feedstuffs of the cow and transfer it into nutrients that the cow can then digest. And those are in the form of volatile fatty acids. So that's the energy source for cattle. It's actually made by the microbes. So when we feed cows, we're actually feeding the microbial population inside the rumen, and then those little buggers are going to feed the cow. From here, the ingesta will move sort of back through the reticulum a little bit and into the omasum. The omasum is also called the Book of Leaves. It's essentially designed to filter out water from the ingesta for the cow to use for their hydration. And then it will move into the abomasum, which is really the true stomach of the cow. This is the glandular stomach, the stomach that you are most familiar with that is an acidic environment that digests feed. So that's the last compartment and then it will move to the small intestine. Rumination is the process by which these microbial populations digest the forage that the cow consumes. And in order for them to do that, there's two very important components that have to happen. Cows produce massive amounts of saliva and in that saliva is a buffer. The rumen pH needs to stay at around seven in order for that microbial population to be happy. So you will often see cows with saliva in their mouths and they go through this process of regurgitation. So a cow, as the gas builds up in the rumen, in the cow, it will put pressure on the base of the esophagus, the lower esophageal sphincter, and cause the cow to belch. It will also bring up ruminal fluid and what we colloquially call a cud, and the cow will then read chew or remasticate this material and re-swallow it to get the particle size or the size of the ingesta down small enough where the microbes can actually digest it. So both of these processes, both eructation and or burping, or, and regurgitation, or chewing your cud, are incredibly important for the successful, for a happy digestive tract. And when things go wrong in that in that realm, we have problems. So this is just an image of a cow chewing her cud. Happy cows will be laying down in a barn, chewing their cud, loving life.

Heart and lungs in the cow. I like this image here because it gives you a demonstration of just how far cranial you have to go in order to ascult a cow heart. Really, you have to, and I'll show you a picture of this, but you really have to jam your stethoscope right up under the shoulder, the point of the shoulder in order to ascult the heart, because it's very cranial and comparatively small. So just to give you your landmarks, the lung is removed from this image. The esophagus is this fellow here coming down and going into the rumen, this is the spleen, and then this is the rumen, this big huge, all of the left side of the cow, almost all of the left side of the cow is just rumen. And so when I show you images of doing a physical exam, you'll have a better appreciation of where you need to be to listen to heart and lungs versus where you're going to hear the digestive tract, which is most of the left side of the cow. The other thing I want, so this is a lung over here and the heart would be just deep to this or medial to this lung. This structure here is, so we're looking at the right side of a cow that has died that I'm doing a postmortem on, this tissue here is the muscle of the diaphragm. This is the liver. And if we were looking at this on the left side of the cow, which you can see here, this triangular structure would actually be the reticulum. And this is important. You can see here, here's the heart. Here's the diaphragm. And here's the reticulum. Cows are indiscriminate eaters, much like Labrador retrievers, which I have. And on occasion, they can ingest metal. And because of this anatomy, anything heavy that the cow digests typically falls into the reticulum and stays there. It doesn't move out of the reticulum. The Reticulum sits right behind the diaphragm, flush up against the heart. And so that can cause disease, which we'll talk about later. But I wanted to have a really clear image in your head of this anatomy. That matters.

We'll talk a little bit about milk production. I didn't go into great detail about beef production, but certainly if you have questions on that, I'd be happy to answer it. Dairy cows are athletes just in a very different way. The average milk production of the of the modern day cow is about 80 pounds of milk per day, per cow. To give, put that in a perspective that you better understand. Perhaps a gallon of milk is 8 pounds, and so that's ten gallons of milk from one cow every day. Milk production requires reproduction. Cows have to have calves in order to make milk. They're first bred, heifers, which is the term for a female cow that has not yet had a calf, they're first bred at around 13 months of age. And it's a nine month gestation. Cows are typically milked after they have their calf. They're typically milked for about 305 days. And then they will be during that time, they will be re-bred to to get them pregnant again. And they will go into a dry period subsequent to their next calving. And so that's the rest of those 60 days of a year. They get to have a two month dry period where they're no longer being milked. Dry means they're no longer being milked and their bodies are just sort of recuperating. They're spending all of their energy growing that calf and no longer having to produce milk at the same time. Cows are typically milked 2 to 3 times a day, depending on the production system in a parlor by machines. So this is a demonstration of that. These machines are placed on a clean udder and the milk flows out of this, out of the udder, into this machine and down tubes, into tanks where it's picked up by by big trucks. And then the udder will fill with milk. This is a very full mammary gland prior to milking. You can see that there's even a little bit leaking out of the teats. So milking is very important for the health of the udder.