So good evening, everybody, and thank you very much for joining us for tonight's webinar, which has been, which will be presented by Jeff Smith. So Jeff received an AS in animal and dairy science from Clemson University in 1994. From there, he received an MS in toxicology from University of Illinois in 1996, and a, DVM in 1998.
Following graduation, Jeff remained at the University of Illinois for another 4 years while he completed an internship and residency in ruminant internal medicine, along with a PhD in physiology. He then joined the faculty at North Carolina State University in 2002 and is currently a professor of ruminant medicine in the Department of Population Health and Pathobiology. He is a diplomat of the American College of Veterinary Internal Medicine, and his primary clinical and research interests revolve around clinical medicine of ruminants with a specific focus on calf health.
This is Jeff's first webinar for the Webinar vet, and tonight he will be discussing razing healthy calves. So over to you, Jeff. Thank you, Carolyn.
As she said, my name is Jeff Smith and what I'm gonna do is kind of talk about some philosophy around raising calves, primarily dairy calves. I'm gonna, I've got a lot to get through in a relatively short amount of time, so parts of this, I may go pretty fast through. But in general, this is more philosophy than science.
Again, my attitude towards being a dairy calf veterinarian or even a beef calf veterinarian is that most of the diseases we see are management related. Certainly, we have good vaccines out there. We have good antibiotics out there, but generally when I approach a calf mortality or calf disease problem, whether it's diarrhoea or pneumonia, usually I'm trying to figure out what are the management factors on this farm that are really causing this to happen.
Most of the time when I run into a severe diarrhoea or respiratory problem or septicemia, there's something on the farm, whether it's poor choloster management, poor housing, there's something that's causing that to happen. So, that's what I'm gonna spend most of this seminar talking about. It's just risk factors for disease, key things.
That we can do on a dairy to try to prevent disease, OK? Certainly a lot of producers will call me. I'm a faculty member at the university and they want help with their vaccination programme with something else when in reality, there's probably something else on the farm that they need to fix rather than just adding treatments to a programme.
You know, these are United States numbers, but if we look at percent calf mortality before weaning, typically before 8 weeks of age here in the US, there's still improvement, OK? We've improved a little bit over the last 30 years, but we still have pre-wean heifer calf mortality of about 7% according to the last United States Department of Agriculture survey. You know, and really we're pretty lucky in the cattle industry as compared to, for example, the swine industry.
They seem to get a new nasty virus every 5 to 6 years, at least they have in North America. Whereas our diseases largely are the same as they've been for. For the past 40 years, diarrhoea is still caused mainly by crypto and rotavirus.
Pneumonia is still, you know, you could argue mycoplasma bovis is a little bit new in the last 20 to 30 years, but we still have the same pneumonia pathogens we've really always had, . You know, many farms are still doing a poor job of cost or management, even though we've stressed for years that that's really, really critical. OK?
So again, This is US data. It may vary a little bit in your countries, wherever you're watching the webinar from. But if you look at from the early 90s to the last time they did this, these are National Animal Health Monitoring survey numbers.
So this is not all data from the US dairy industry, but this is a pretty wide representation of the US dairy industry. Prewan calf mortality is considered any death loss from a calf 48 hours of age until weaning. If it dies between birth and 48 hours of age, typically that's considered a stillbirth.
And those are about 6 to 7% too. So if you think about 6% of our calves are stillborn, another 6 to 7% die before 8 weeks of age, that's pretty significant mortality in the dairy industry, OK? Percent of deaths caused by diarrhoea, 55 to 60%, percent of deaths caused by pneumonia, 25%.
You notice as we move towards group housing in the dairy industry, that number is actually getting larger. OK. After weaning, our mortality will, will go down significantly and respiratory disease seems to be our main problem.
So what should goals be? Typically, I say goals, if you have more than 4% calf mortality between birth and weaning, I think there's room for improvement. Most of our exceptional dairies will get that number.
Less than 2%, you know, if you're at 1 to 2% calf mortality, that's probably as good as you're gonna be. Certainly, we would rather not lose any calves, but, you know, I think 1 to 2% is is very strong. You're less than 4%, you're probably acceptable.
You know, certainly we, you know, I went to a dairy the other day that has 25% calf mortality and, you know, unless they change some facilities. They, that may not get better for a while, but, you know, there are farms that we live with it about 4%, but I certainly think that if a dairy has more than 4% mortality, they should at least contact the veterinarian, get a walk through and see what things we could do to improve. OK.
Morbidity treatment rates definitely should be less than 25% in terms of cabs I'm treating for any one disease. And typically for pneumonia, I would ideally like to see that less than 10%, OK? And we'll talk about why that is a little bit later.
And I would encourage you, I don't want to spend too much time on records, but I would encourage your producers to use records when possible. Need to convince people that these are important. Our dairies do a pretty good job keeping records on the cow herd, not always a very good job keeping records on the calf herd, OK.
So typically, I like to see two kinds of records. This is kind of what I would call a birth record where we've recorded, you know, the calf's number, what time was it born, who saw it, when it was born, what time was it fed Colostrum, if they're doing any, any kind of following, follow up total protein testing, we can record that there. What this will help me do is, you know, if they say I seem to be losing a lot of calves, is this stillborn problem, dystopia problem, or is this really calf mortality?
If there's a colostrum problem, I can figure out, are they recognising these calves after birth quickly? Who's feeding them on a big dairy is this one employee I'm having a problem with. These are very helpful to get real data rather than just kind of what the opinion of the producer is that day.
And then ideally we would have some other record that goes with the cap on whatever treatments they get. If they get a vaccine, if they get an antibiotic, if they get castrated, if they get dehorn, all that information gets written on the sheet. And really these records is the, are the only way for me to figure out is the veterinarian if I'm on the farm once a month or however often I'm there, what's the true morbidity, what's the true mortality?
You know, if I'm using a certain drug for pneumonia, is that working? Are they consistently curing, or they, or do they often have to move to a different antibiotic again, rather than just kind of getting the person's take on how things have been going, it's nice to have records to look at, OK? Helps me monitor treatment success.
That's it for records. As we get into kind of risk factors for disease and disease control, I always like to show this slide, and this, this comes from Doctor Otto Ratas, who is a, a Canadian who passed away a number of years ago, but he was kind of one of the founders of bovine Veterinary Medicine in North America, and He came up with what he considered the four key principles of disease control, and this was designed for beef calves in Western Canada, but really fits well for dairy calves too. He said the things we can do to prevent disease were removing the source of infection from the calf's environment, keep the calf in as in as clean an environment as possible.
We can remove the calf from a contaminated environment. Think about the calving pen or away from the cow. As quickly as possible.
We can do things to increase the immunity of the calf, and then we can try to reduce stress, OK? But there's, you know, if you think about things that we do to raise healthy calves, there's really nothing we can do that doesn't fit in one of these categories, OK. So pretty much this is all we can do to try to prevent diarrhoea, to try to prevent pneumonia, to try to prevent other diseases is kind of think about these four things, even if we're talking about improving nutrition.
You know, that's reducing stress, that's potentially increasing your immunity. Everything fits into one of these categories, OK? So choloster management, this seminar is not meant to be a seminar on cluster management.
But I would say if you're having a calf problem, whether it's too much disease, whether it's mortality, this is kind of where I often start, a good cluster management programme, making sure that all calves get an adequate volume of quality colostrum. As quickly as possible is really important, OK? So one slide on Colostrum and then we're going to move to something else.
We know that the timing of feeding is critical. The sooner we can get the colostrum out of the cow, the better quality it's going to be. The sooner we can get it into the calf, the more efficient the absorption is gonna be.
So we say 2 to 4 hours again, we have smaller dairies here. Our small dairies are 100 to 200 cows. Where people go to bed at night.
So I can't really tell them every 2 to 4 hours. To me, I tell them that if you go to bed at night, you come out, you find a calf the next morning, that calf now becomes your biggest priority of the day. I'm not gonna do chores.
I'm not gonna milk cows. I'm not gonna feed. The first thing I'm gonna do is harvestlostrum and feed it to that calf.
We need to make sure in the dairy industry, we're feeding 3 to 4 litres to every calf. Obviously, a beat calf is probably not drinking that much, but the. The quantity or the concentration of immunoglobulins in the colostrum tends to be much higher, so they don't need the volume.
Cleanliness of lostrum is important. If it's contaminated with bacteria that will cause increased rates of failure of passive transfer. I traditionally say test some cabs, even if you're not testing regularly, at least periodically, whether the producer is pulling blood or whether you're the veterinarian, are pulling blood during a visit.
You know it's nice to keep a periodic check and make sure things are going well, and make sure this is a priority on large dairies they usually try to put somebody in charge of this if there's more than one person taking care of the calves, you know, there needs to be somebody that takes ownership of this programme. We may even, you know, potentially put bonuses into somebody's paycheck based on how good the total proteins are from time to time. So this has nothing to do with Colostrum.
But this is an example of something that we deal with, and I don't know, you know, what country you're watching from in the United Kingdom or, or in Europe, but I know some of the dairies are pretty small, some of the countries have larger dairies, but certainly on our larger dairies, we have probably 20 dairies in North Carolina that would be 1200 cows or more that have employees come and go a lot. And the reason I say continue to do to periodic total proteins is because of this. So this is a form that we regularly visit through the university that for 34 months had a lot of umbilical hernias, all the time.
We kept asking them, you know, how's the housing, is any of the betting changed or you're still dipping with iodine? Yep, everything's fine. You know, but the, the students were getting a lot of practise doing surgeries on these umbilical hernias, but we couldn't really figure out what was going on until one day we were, we rolled this calf over and you'll notice here that the iodine is actually on our teeth.
It's not on the umbilic it's over here. Well. One of the employees that took care of the calves left, and they had a new employee that was a short fat guy that couldn't see up under the calf, and he had been kind of throwing the iodine up to where he thought the umbilicus was.
So nobody's been dipping the umbilicus for about 4 months, OK? So yes, it took that long for everybody to figure things out. But at least on dairies in the US I kind of call this employee drift, where we start to do things right, we've got the problem fixed and then we kind of slide back into old habits.
So, that's one of the reasons I like to at least periodically monitor proteins just to make sure that the Closer programme is good. And if I see the total Proteins start to slide back, then I can go out and say, hey, what's going on? Are we still doing the same things.
Oftentimes, the farm owner or manager, what they think the protocol is that's being followed is not exactly what we find that's being done by the employees sometimes. On smaller farms where the owner is feeding the classroom, that may not happen, but certainly if you have multiple people involved in the calf raising process, this is a good idea. OK, control points, things I look at when I go to a dairy, when I'm looking for sort of a calf disease problem, the calving area.
OK, calves are frequently exposed to disease from the dam at birth. I know there are different regulations, different thoughts in different countries, you know, one of the, the hot welfare issues amongst the public is, why are we separating the very young calf from the cow in the United States. Our goal is still to get that calf away from the cow.
As quickly as possible. We know that's a dirty environment. Multiple studies have shown that leaving that calf with the dam is a major risk factor for disease, including cryptospial diarrhoea.
In other countries, it's mandatory now to leave the calf with the cow for 2 to 3 days, so they can't do that. But we wanna make sure that whatever place the calf is born into is clean, OK? So this can be a challenge on big dairies as well.
There doesn't seem to be an advantage to individual calving pins versus group calving pens, as long as they're well managed and kept clean, the risk of diarrhoea has not been shown to be different. Between multiple calving pin types. So this is a dairy we go to that had a lot of problems.
They had a very dirty calving environment. This is about an 1800 cow dairy. So you'll notice there's another fence over here in the back and everything on that side of the fence is my close up cows that are close within a couple weeks of calving.
What we did on this dairy was instead of having one big calving pen, we put another fence up. This dairy milks 3 times a day, so there's somebody's there almost 24 hours a day, every time. The milker goes to get the next group of cows they passed by here and when they notice a head or a feet sticking out, they will move the cow into this area, which stays relatively clean.
The cow will go ahead and cab there. There's on this side over here, there's a portable. Milker where we can get a colossum harvested pretty quickly and then that cow and the calf are out of this calving area and still this area is we pick up the straw, the sand, everything and completely rebed it about 3 times a week so we can manage to keep this area pretty clean.
In general, this doesn't always hold true, but if you're dealing with a disease problem in calves less than a week of age, I look really hard at the calving pen. What's going on in the calving pin? If the disease is 1012, 14 days of age or older, you know, it's probably more likely they're picking that up in the hutches or the calf barn or wherever they're growing up.
Colostrum, we talked about the benefits of Colostrum, but certainly colostrum can be a risk factor for disease. Colostrum can be contaminated with salmonella. It can be, it can contain bacteria that cause septicemia.
You know, there are diseases that can be transmitted. So we gotta think about that as well when we're talking about colostrum. Certainly, we want a good quality colostrum programme.
But never close your mind into thinking about this as a possible source of disease spread transmission as well. Housing is really important, OK? And I'm not necessarily gonna say there's the best type of housing.
We have dairies that use individual plastic hutches. We have in the dairies that have calves and barns that are individually housed in wire pins or wood pens. We have dairies that do group housing.
But I think making sure that those calves are housed in a very clean, dry environment with good drainage is important. In group housing systems, we want to keep our group small. They've shown that no matter how much space the calf has.
If you have about more than 12 to 15 cats per group, your risk of disease is gonna go up, OK? So we need to think about, you know, these diarrhoea pathogens are all fecal-oral. So anything we can do to eliminate or minimise fecal-oral spread is really critical.
So this is a dairy I went to in salmon in not salmonella in Mexico, 3 or 4 years ago that had a really bad salmonella problem. You know, I tried to explain to them that, you know, your calves are right by your manure handling equipment. Certainly you're aerosolizing some salmonella that can that can live in the soil for years, and they were insistent that that wasn't true, so we took some samples of the soil here of the sand.
We were able to grow salmonella right out of the calves environment up to a couple 100 metres away from where this place was. So they're literally feeding their calves salmonella here. So, you know, put some thought into where you're gonna put your calves.
Certainly don't want them downhill from the adult cow herd. I don't want any manure from the adult cow herd to be anywhere near where, where my calves are. Think about calf density, OK?
Certainly, as we have more calves in a closer contact, we're gonna increase the risk of fecal-oral transmission. You know, I'm not gonna say there's one best way to house calves, but these are all examples of what I think are pretty high risk for diarrhoea. You know, here I have nice hutches, but they're touching each other.
These calves can easily have spread manure into the next hour or maybe even two hutches down. You know, here you see wire separating these calves, these calves are in a barn with wire pins. There's virtually nothing to prevent disease in this type of setting.
Again, I'm not saying these are ideal ways to house calves, but here I have hutches spread out more. I have solid side pens, OK, I, I have hutches that are spread out. These are all pictures from various countries, different ways of raising calves.
I would also say compared to the previous slide, these are lower risk for diarrhoea, just because our cal calf to calf density is decreased. Nutrition. There's data now.
I think we've always known this, but there's data that says if we feed calves more, OK, instead of just 4 litres a day, if we feed 6 or 8 or even 10 litres a day, we can reduce disease. Good nutrition is necessary to maximise immunity. Obviously, if you're hungry, you're stressed, starving calves are much more like, more, more likely to die, particularly when it's hot or really cold, OK?
There are studies that have shown with crypto with salmonella models that Calves that are on higher planes and nutrition are more resistant to disease, or even if they develop diarrhoea, they get over it faster than compared to calves are on more conventional nutrition programmes. And whether that nutrition is directly regulating things like growth factor or insulin like growth factor, we don't really know, but it definitely seems to play a role in enhancing immunity and allowing those calves to handle this disease better. OK, As we talk about sanitation, this also becomes important, OK?
If you're using a pasteurizer, make sure it works. If you're using whole milk, which is common in some countries, are they feeding mycoplasma, are they feeding pathogens to the calves? If so, you know, we may need to pasteurise that milk.
Think about the feeding utensils, buckets, bottles, washing those is nobody's favourite job, but those are really important. On big dairies, how is milk getting delivered to the calves? A lot of times I see very clean milk going into transport systems, but very dirty milk in terms of bacteria when it's being actually fed to the calves.
OK. Things like calf formers, temporary holding pens, vehicles that haul calves around. I'm not saying we can't use those, but they become very good places to find disease, OK.
I live in a pretty warm environment, but if I want to find a pathogen, and they're using a calf warmer or cap hot box like you see in the bottom corner, my culture that I'm gonna find whatever is going on in the dairy for sure. OK. So things like that, I'm not saying we can't use them, but they do tend to be bottlenecks for disease or spreading disease or places where every calf gets passed through and potentially gets exposed.
You know, when I'm on farms going through this, a lot of times I'll try to trace the calf from where it's born to where it's gonna be weaned, look for manure transfer, particularly from adult cows, but spaces or bottlenecks where those calves are frequently in contact with other calves where disease could have been spread, OK? If you're feeding a lot of milk replacer. We also want to make sure that that's consistent.
We want to make sure that we're feeding milk or milk replacer with a pretty modernised morality. Generally, the recommendation is total solids of 15 to 16% or less. How do you know?
Brick refractometer, if you're doing a lot of dairy practise is very helpful. This is an example of a brick refractometer in the corner. These actually come from the food industry.
So a bricks scale or a bricks reading. Is a measure that corresponds to the percent of sugar. If you make a solution of sugar and water, so basically what percent bricks is, is the grammes of cane sugar and 100 grammes of cane sugar solution.
But this gives us an idea how concentrated the milk or the milk replacer is, OK? Obviously, whole milk is about 12.5, 13% total solids.
The more powder, the more antibiotics or the more stuff people start putting in there, the more concentrated that becomes. When we get to 18, 20% total. Solids, we start having blow, we start having other issues, OK.
The other thing I like to do on, particularly on big dairies is milk, make sure the milk replace your mixing is consistent. The way I do that generally is I measure some of the milk right at the first calf, maybe the middle calf, and then at the last calf they're feeding. If my brick reading is varying by more than 1%, they're not doing a very good job getting that mixed up.
And what you'll see clinically is Periodic blow in those calves, OK. Try to be consistent with your feeding schedules, even if they say, you know, I can feed at 7 a.m.
In the morning and 4 p.m. In the afternoon.
As long as it's consistent with that, the calves will be fine. You know, when feeding varies by 2 to 3 or 4 hours a day, depending on other chores, we see a lot more stress, a lot of hunger stress in those calves, OK? .
And then make sure we offer clean water to calves at all times, even right from day one, they may not drink a lot of water, but they get pretty used to having it there by 78 days of age, they'll be drinking a lot of water as well. And then minimise stress, OK? A lot of people think, well, what's stress in the calf's life?
Well, calf actually has a lot of stress. It's hungry, OK, sometimes we move these calves a lot. We certainly wean them early for take them from their mom.
Bad weather right now where I live, you know, we're We're 29 to 30 °C in the afternoon here in April and May, but it may get down to 7 or 8 °C at night. So this is pretty much national respiratory disease or national pneumonia month for us. Those calves are really stressed from warm days and cold evenings, OK?
So, all those things could potentially increase disease. If you are kind of a new concept that we know about, this is not a cow thing, this is a science thing. This has a lot to do with food safety and like the poultry industry and the swine industry.
There's a concept called quorum sensing, and what they've shown is a lot of bacteria have the ability to kind of go dormant in the gut. And then when that animal starts to get stressed. They will start dividing.
They'll come out of hibernation if you will. What they're doing is they're responding to increases in intestinal norepinephrine concentrations. So you can have a a pig.
You know, we go in right 2 days before slaughter, we culture the whole barn and we can't find any salmonella when you actually reculture them as they get to slaughter, maybe 10-15% are shedding salmonella. Probably that salmonella was there the whole time and as those animals got stressed from being loaded onto the truck and shipped, they start shedding. OK, if you talk to veal operators, if you talk to some dairymen, they'll say, you know, most of the year we do fine, but every April or May we have pneumonia outbreaks, and that's probably not new pathogen, that's probably stress causing that disease to occur.
So, you know, some things like weather we can't control, other things like making sure we're not constantly moving calves every week, we can't control. So in terms of control point summary things that I try to tease for raising healthy calves, make sure my cholesterol management is good, make sure the maternity area is as clean as I can get it. Nutrition is important.
We didn't spend a lot of time talking about what is good nutrition, but that's something that we're learning more and more about. Feeding calves more and more frequently is important. Appropriate housing, OK?
Minimising manure contact between calves and older cattle. Sanitation, of feeding equipment of environment of hutches of facilities, and then avoiding stress as much as we can. OK.
Things that I look at from time to time, particularly on dairies where I may have a diarrhoea problem and I just can't seem to figure it out. I'll come back and do cultures of milk. A lot of times we have milk that get contaminated, and I'll actually kind of any lab that does traditional milk quality assessment, can do a total bacteria count, can do a faecal coliform count.
If people are sticking their hands in the milk to mix it, if you have dirty feed delivery equipment. You know, we can have a lot of bacteria in the milk. So this is probably more important, particularly on larger dairies than we ever thought.
And this is something I do probably not on the first visit, but if I continue to have problems and can't get things figured out, sometimes it's because the bacterial counts in the milk are too high. OK. So I may have to go out, if, if, you know, if they've got a half a million bacteria in the milk, I may have to go out and watch them.
How are they making the milk replacer? How are they feeding, what are they putting in and how are they mixing, rather than just usually just accusing them of having dirty milk, I'll say, I like to watch the feeding process and I try to figure out what's going on before. I tell them because usually if I say, well, the milk's dirty, they'll they'll say no, it's not, and I really can never figure out exactly why it was dirty.
OK. So this is a farm I went to, and I'll say this from being a long story, but we did multiple cultures of milk before it was, this is water, this was milk, this is how it was being delivered to the calves. We did a whole bunch of cultures and the milk was clean going in, but if I cultured it out of the casts bucket, it was really dirty and ultimately we cut this plastic hose off and there was congealed or curdled milk all the way down the centre of the of the tube.
This was a rubber hose kind of like you'd find at a gas station and once we replaced that hose, our counts in the milk went down and we saw our diarrhoea levels go way down. So it's not always just. Pathogen.
It's not always rotavirus, cryptovirus, sometimes it's things that we've caused through management problems that's causing the disease. OK. Again, sanitation, this is nobody's favourite job, but this is an important thing to do as well.
Now, I want to talk some about pneumonia. And you know, this is kind of increased in importance. I said this was kind of a distant number 2 behind diarrhoea for reasons why we had mortality in the dairy industry.
One of the reasons this has become more common, and one of the reasons I said earlier, instead of having a 25% acceptable treatment rate, I'd like to see this 10% or less. What we've learned in the last 10 years or so is that if you have pneumonia as a calf, you're much less likely to be productive when you enter the cow herd, OK? There, there's no data like that about calf diarrhoea.
There's no data that says if you survive diarrhoea, you're gonna have reduced milk production in the cow herd as compared to calves that didn't get diarrhoea. But there is that disease for pneumonia. OK.
So we've known from for a long time that if you have pneumonia, you're gonna have a reduced growth rate. You may get bread a little bit later. But again, newer data in the last 10 years.
This is a study from the University of Wisconsin that followed calves through their first lactation. They divided calves into two groups, those that have been treated for pneumonia during their 1st 60 days of life, and those that did not. OK, so that you looked at a number of those calves, percent that survived calving, only 66% of pneumonia calves survived to make it into the lactating herd as compared to 85% of those that had not been treated, OK?
So significant difference there. There was another study that was published a few years back, and this was done on about a 3000 cow dairy in in the state of Utah here in the United States. And again, this was a retrospective study, just pulled off of records.
Here they defined pneumonia as any calf that had, according to their records had been treated for pneumonia before 120 days of age. OK. So, this is number of calves born a year, about 2000 calves a year, 14,000 calves total.
Number of calves that have been treated for pneumonia, about 6%, which in the United States, I'd be really happy with that. A lot of, a lot of our big farms are much higher than that, percent of deaths due to BRD about 20%. What they found is, About 35% of the pneumonia heifers departed the herd before calving, as compared to only about 17% of those that did not.
So again, if you have pneumonia, you're much less likely to make it into the lactating herd. They also found that the heifers that did make an end to the lactating herd had over a 500 kilogramme decrease in milk production during their first lactation. And there's other studies that have now shown this, OK.
So the reason why we're gonna work so hard to prevent my heifers from getting pneumonia, is this really is correlated to their future productivity, their potential for productivity, once they the lactating herd, OK? So instead of looking at these heifers as an expense, really I try to get producers to look at them as an investment in the future. If she's a crap heifer, she's not going to do well when she enters the milking herd.
It's just not about keeping her alive, getting her pregnant, and getting her in there. But I need good lungs. I need a functional animal that will be a good cow once she enters the lactating herd.
OK. So again, prevention is important. A lot of things we've talked about already, good colostrum, nutrition, biosecurity, housing.
One of the big things that's different about respiratory disease is compared to diarrhoea in terms of housing and environment is that ventilation becomes really important. We've done a lot of work here in the US that just emphasises the importance of ventilation in terms of preventing respiratory disease in these young dairy calves. So again, just like with diarrhoea, there are studies that show nutrition is important, OK?
And one study calves that were on a higher plane of nutrition had a lot lower incidence of respiratory disease, particularly during the winter months. This was a study done in Minnesota, which is a very cold climate. So again, nutrition is somehow modulating the immune system.
There's some connection there that's really important. Again, when we talk about biosecurity, we want to try to prevent again nose to nose contact. Most of these pneumonia pathogens are spread by nose to nose contact.
So when we think about preventing faecal world contact, that also would prevent nose to nose contact . We want to monitor our pasteurizer performance, particularly on dairies that have a mycoplasma issue, making sure our milk is clean, high bacterial counts in the milk have been associated with increased rates of respiratory disease. Again, in terms of ventilation, really avoiding overcrowding is important, but also kind of the design of the barn is important as well.
OK. So there are a lot of studies here in the US as well as in other countries that have linked respiratory disease and young calves with poor ventilation. It's also important to understand that there are microenvironments within a barn.
Just because the air quality is good where your nose is, doesn't mean it's necessarily gonna be good where the calf's nose is, OK? So we need to get down at the calf level when we're looking at air quality. OK, so these are cabs outside.
This is the dairy, where I live here in North Carolina. I really don't like the tethering of the cabs where they're on a chain or a strap. I would much rather see a wire pin around front where they can walk around.
But this is kind of the gold standard when we talk about ventilation. These calves are outside, they can breathe clean air. As long as they're not really crowded together, you should see pretty low rates of pneumonia in this type of environment.
There are exceptions, but, you know, in terms of inhalation, this is pretty good, OK? Here we have very good ventilation. So we have open-sided pins.
We have a ridge vent up here for bad air to get out. OK, but my biosecurity is not good. OK.
So these calves can touch noses, you know, pneumonia can spread right down the row of these calves. So there's always a trade-off between good biosecurity potentially and good ventilation. We'll talk more about that.
We have a lot of barns like this, particularly as we get into colder parts of the United States. Perhaps these are old swine barns, old turkey barns, they got renovated into the calf barns. A lot of times these barns are more for the people than they are the calves because they don't want to get cold while they're feeding.
You know, they'll have the curtains are closed. Normally those curtains are open, so prevailing winds can fresh force fresh air into the building, you know, you don't see a ridge vent at the top like we did on that last air, so we have a lot of stale air that stay up here, you know, in these barns, the air quality becomes really poor and our rates of pneumonia go way up. OK.
So even in North Carolina, which would be kind of a warm weather part of the United States, we'll see old barns like this. We'll deal with lots of respiratory disease in this type of setting because of poor ventilation. OK.
We have greenhouse style barns. This is a group housing system, where these cats will be on automated feeders, see a ridge vent up here in the summertime we'll open these garages and get fans moving air through. We can pick these curtains up in the wintertime, we can close things down a little bit more.
But anything we can do to increase the air movement through here is really important to improve ventilation, OK? You know, in climates like the United Kingdom where it can be cold, what they've actually shown is you're better off keeping those curtains at least partly open, and bedding the casts pretty deeply in fresh straw, letting them nest down in there. They'll get a lot of thermal protection from the weather from that straw.
And as long as we can keep some air moving through the barn, we'll see better air exchange, better ventilation, and typically lower pneumonia rates in those calves. OK, so this is a poor stall design here. This is concrete on all three sides.
We're not gonna have much air movement at the level of the calf, but this is very good, what I would consider nesting, OK? So if I look at this calf, I can't see its legs. It's completely kind of halfway buried in straw.
This calf can handle it at 5 degrees or 678 °C, because he's buried in that straw pretty well, OK. Solid sides are important if you're gonna have barns, that actually is gonna decrease the ventilation a little bit, but there are studies that show that also decreases the treatment rate for respiratory disease. Again, we're sacrificing a little bit on ventilation, but we're improving our biosecurity by having solid dividers, preventing our calves from being able to touch nos.
OK. And again, this is kind of, I, I showed you this picture earlier, very good ventilation, bad biosecurity, OK? People have seen these plastic styles of hutches where they're solid all the way around and the cat just has a little hole hole to stick its head out of to eat or drink.
You know, these are really good for biosecurity. There's no nose to nose contact. There's no faecal oral transmission.
But the ventilation at the level of the calf is terrible in these things, OK? You see some big bands in this barn. This is an example of where the ventilation for you might be pretty good when you walk into the barn.
But if we get in and look at the ventilation where the calf lives, it's not very good at all. OK, one of the ways we've been able to kind of study this or show this to producers is by actually doing cultures of the air, OK? So we're using a machine that will suck 1 cubic metre of air across the plate, culture plate, and we can look at what are the concentrations of bacteria in the air.
You know, we don't really have goals for what they should be, or at least we didn't at the start of this, but typically in humans, so if they come in and do air cultures or factories or settings where lots of people work. Typically they say more than 10,000 colony forming units per cubic metre of air is considered dirty or contaminated. When we say dirty, you know, these are staph, streps, bacillus, maybe an E.
Coli, they're not manhyia, they're not pastoral, they're not pathogens, but they're bacteria in the air that are representative of the quality of that air. So this is the machine we're using. This is made by a company called BioMer you.
I can put the plate on top, I can press a button, it'll suck through a cubic metre of air. These are easy to use. They're expensive.
This machine in the US is about $8000 so not everybody has one, you know, but certainly a lot of the companies do. So if they have a technical services veterinarian, a lot of times we, you can borrow these or you can get them to come in and, and do some air cultures for one of your clients' farms. And this is what they'll look like.
And again, typically I either set this machine on the floor. Or hold it kind of level with the calf's nose and I'll do culture at certain different places in the barn, not just one area. So maybe one corner, maybe where the calf lives, maybe up front of the barn.
And the good thing about this is, you know, I can then I didn't have data to come back and show the dairymen, hey. It should be 10,000, it should be 30,000 colony forming units per cubic metre. You've actually got 2 million bacteria in the air in your calf form.
So, me and other people have done a little study where they measured air quality in 100 different ca barns from 12 different states. Remember, greater than 10,000 colony forming units per cubic metre is considered normal for people. What we found in calf barns is it often exceeds 100,000, so 10 times dirtier than what we consider safe air for people.
The other interesting thing was that we were able to show very high correlations between bacterial counts in the air. And the percent of cabs that we were, they were treating for pneumonia. We also had very good success by them doing something to improve ventilation, some type of inter intervention, going back out and repeating air culture, showing that the bacteria went down in the air and then showing that their treatment rates for pneumonia went down as well.
OK. So again, housing density is one of the things we can control. How many calves do I stuff in a barn?
And you know, again, just like for diarrhoea, I'm not saying any of these are ideal or necessarily bad in terms of calf housing, but they all are what I would constitute pretty high risk for pneumonia, OK? Environments like this are lower risk for pneumonia. Here's an example from Mexico.
I was on a farm in Mexico consulting for a company back in 2009, and I was actually doing fresh cow transition cow work. As we were leaving, you know, I said, how are the calves going? They said, you know, we're treating a bunch of them for pneumonia.
Our records indicate that 33% of calves are being treated for respiratory disease before weaning, and again we're walking to the truck and I said, well, the hutches are awful close together. It was really hot on this dairy. I said, you know, you're not managing the heat stress very well.
We should get a cheese cloth or something above them and spread these hutches out, that might help. Lo and behold, I was back on the same farm the following year, and they had done that, OK, so they normally had these tarps above the calves, providing shade. They had spread these hutches apart, and they said they were down to treating about 5% of these calves for pneumonia.
Now certainly other things could have happened from one year to the next. But it seemed like improving the air quality here, decreasing the stress of heat, really seemed to help. OK.
So if I do have dirty air, what can I do? Certainly I can take some of the cats out of the barn. Obviously the producers got to figure out where to put them, so that's, I understand that's easier said than done, but just increasing the area we allow that calf can inherently decrease housing density, make the pens bigger, put fewer in a barn.
If you have solid panels on the in the front and the back. You know, put holes in them, make sure they're not solid anymore, get more air flowing through that hutch or pen, even putting a concrete block under the back of the hutch, something to introduce more air into that situation will help. And then we can always go to supplemental mechanical ventilation.
On a lot of dairies we've gone to putting these positive pressure ventilation tubes. This is probably not a long term fix, but if, you know, if I tell a dairyman you need a new calf born, yeah, you know, that's not gonna happen tomorrow. That may be 5 years down the road, that may be 10 years down the road, and these are good band-aids to help us get there, OK?
So if you think of a fan blowing air as negative inhalation. This is positive pressure ventilation. So what we're trying to do is take fresh outside air, force it through a duct system, OK?
And we, you know, we make these out of fabric, polyethylene, usually not metal, usually these are much cheaper than metal and they work well. You notice the holes are kind of on the side, so they don't blow directly down on the calf. We're introducing small volumes of fresh air into the barn without really creating draughts, and this can take an old barn and really make it livable until such time where they can expand their facilities.
You know, one of the reasons I like the air culture system is, I have a lot of dairymen, you know, when I'll say this barn is not appropriate for raising calves. This is why you're getting pneumonia. They'll say, well, you know, my father raised calves here, my grandfather raised calves here.
I don't see what's changed. You know, in the United States, what's changed is their grandfather milked. 30, 40, 50 cows.
The father may have milked 100. Now they're milking 800 through the same barn. So as they got bigger and they still try to use the same facilities, we're overcrowded, we see a lot more disease than we used to.
OK. I'm almost done here, just a few more minutes, kind of keys to treatment. Making sure producers know how to identify sick calves early is important.
Whether we're talking about diarrhoea, getting them on our or electrolytes, getting fluids into them, whether we're talking about antibiotics and making our respiratory disease, making sure they get on an appropriate antibiotic quickly. Everything's gonna work better if we can pick them out early, OK? And then Gerrymen need to make sure they're working with veterinarians.
They're having treatment protocols in place, whether that's for diarrhoea, whether that's for pneumonia. Then I like to say, you know, if I'm keeping records, I really want to monitor those success to those protocols. Just because.
I built the protocol doesn't necessarily mean it's perfect for that dairy. I may need to go back and change what I'm doing, change the antibiotic, change how we're doing the treatment protocol because it may, for whatever reason, may not be working on that particular farm. OK, so I wanna go this through this pretty quickly.
I'm running out of time, but there are different types of systems for scoring. Kind of the original respiratory scoring system was developed at University of Wisconsin. There's several other systems that have come out.
But basically, what we're gonna do is score casts on 5 different things, rectal temperature, and I apologise, but this scale was built in Fahrenheit. We can change this to Celsius. You know, but we assigned calves of 012 or 3, whether they have a fever on how high it is.
We assigned them a number based on coughing. If I don't hear a cough, you know, if I climb in to take the calf's temperature and I squeeze its trachea and it gives me a single cough, it gets a 1. If when I do that, it coughs repeatedly or if I actually hear it coughing before I ever climb in the hutch, it gets a 2, and those calves that are repeatedly coughing get a 3.
OK, there's a nasal discharge score, clean nose, a little bit of nasal discharge from one nostril, bilateral nasal discharges the two, then a very thick nasal discharge. OK, there's an eye score, how clean their eye is. And then in year score, we really only see droopy years of mycoplasma boss is part of our problem, you know, sometimes really, really sick calf may have droopy years, but we can add these up together and research has shown that his calf score of 5 or more, even if they don't look sick.
They probably need to be treated for pneumonia, OK, and this has been They've shown this by coming back and doing long ultrasound. They've shown this by looking at bronchoalverava fluids, both cytology and culture. This seems to be fairly well verified, OK?
So we can print sheets off. I can teach just an average worker on a dairy to do this 2 or 3 times a week. Traditionally, I do it in the morning before we feed the calf.
That calf should pop up, walk right out, it thinks it's gonna get fed. I can look at it's not nose. I can look at its eyes, I can look at its ears.
I can crawl in and take the rectal temperature, palpate its trachea. Does it call or not, and go on to the next calf. There are other systems that have been invented where they don't involve taking the rectal temperature on big dairies where they don't want to crawl in and out of the hutches all the time.
They work probably not quite as well as this system, but they do work, OK? So there's lots of things that we can do to train our people that are working on farms to make sure they can detect disease early, OK? And again, We're trying to get pneumonia when it looks like this when we're still in the acute phase versus having chronic pneumonia settle in.
Here you see some consolidation. We have abscesses, we have adolectusis, emphysema. Obviously, this is more difficult to treat and this scarring of the lung, this consolidation is what's causing those happens not to be productive later on.
So everything we can do to prevent that, to catch pneumonia early is really, really important. OK. And then the last thing I want to say, I got a minute left here is just have treatment protocols in place.
And I'm not here to tell you what your treatment protocols should be. I think those need to be designed on a case by case basis between the veterinarian and the herdsman. But make sure that these are simple.
Make sure people that work on the dairy know how to follow them, in the United States, sometimes we have to create these in Spanish, the, the workers may be Spanish speaking, you know, as we look at the industry in the US, it's actually pretty rare that farms have extensive protocols in place, but yeah, these are really, really important to make sure that My goal as a veterinarian for what you should be doing to treat diarrhoea, to treat respiratory disease, and what you're doing on the farm is really the same. As long, you know, if I don't write this down, if you don't have something to follow, you know, you may just treat the calf with whatever you think works, and that may vary from week to week or month to month. So, you know, coming up with protocols for early identification of sick calves, how you want them to be treated.
If they're coughing, if they have nasal discharge, you know, if they have the scours, if they're not eating, any of those would be things that might trigger a treatment protocol, OK? If they have a fever for a couple of days, if they have reduced milk intake, you know, we definitely need to have 2 to 3 or 4 different calf treatment protocols in place. So last slide here again just a reminder that most of what I talked about today is management.
I didn't talk about any specific antibiotic, any specific vaccine, that's gonna vary from country to country, but most of the time when I approach calf health, when I'm trying to raise healthy calves, it's about maximising. The management on that dairy, OK? Now, there's certainly, there's some dairies that are gonna have to get by with.
Housing that's not ideal, but we're trying to maximise what's the best for each individual farm, you know, if we're gonna have poor management, poor housing, I don't know that there's any kind of vaccination that's really gonna get them around that. This is mostly management when we talk about raising young calves. And with that, I've gone 51 minutes.
I'm gonna stop and see if there's any questions I can answer. So I'll stop sharing the screen here and I'll, I've got one question in the chat box. Does anyone have any questions?
Yeah, thank you very much for that, Jeff. That was really interesting. I really enjoyed that.
And so I, if any of the attendees do have any questions, if you'd like to pop them in the question and answer box, and we can pop them, we can, put them to to Jeff. So I'll give you, give you a few minutes if there's anyone who wants to write anything in there. So do you find that many of the dairy farms or many of the, or even the bee farms, actually use these respiratory scoring systems for calves?
Do they, do you see people of our dairies, the beef farms, not as much just because they're not handling the calves on a regular basis. You know, most of our beef calf raising is left to mom. It's not near as intensive as our dairy industries.
Certainly, if I work with the dairy, I don't have all my dairies that are doing this, but if, if I'm treating more than 20 to 25% of the cash with pneumonia, I'm trying to get them to let me train somebody to do the respiratory scoring at least 2 to 3 times a week. And usually, the other thing I will do is I'll come back and look at their records and I, when I, when they're giving say an antibiotic because of pneumonia, what I asked them to do is write down why they're giving it because the respiratory score was more than 5, or because they noticed that calf really breathing harder, maybe that calf is febrile. And really, if their scoring system is working well, at least 75, 80, 85% of the time, they should be catching and recognising these calves are sick based on their respiratory score before they really get this nicker to the point where they're obviously have pneumonia.
So if I come back and look at the records and most of them are being recognised for pneumonia based on respiratory score, I know they're doing a good job. If most of them are being treated because they're breathing hard or they have a fever or they have acute pneumonia, maybe I need to do some more training in terms of my scoring or maybe we're just not using it as often as we should be. Yeah, absolutely.
I think that's such a good idea, and I, I can imagine if you, once you do get, get them implemented in some of the dairy farms, the difference it can actually make, make to, to the whole farm and for the treatments and everything else as well. Any dairy with multiple Employees, I have to train and then I have to do something to monitor because a lot of times what I think it's being done may not actually be what, you know, they may do it for a month and quit yeah so and if and if they have a high sort of stay on things to make sure it's going well. Oh, I bet, especially if they have such a high turnover of, of workers there as well, and you, you can probably get someone trained up working really well, and then they leave and then you get someone new and it's just constant I kind of, oh my gosh.
Yeah, some of them have pretty stable labour and and some there's high turnover. A lot of our workers are from Central American countries, Mexico, Guatemala, you know, they, they come and they go home and, you know, sometimes they come and stay, but there is some dairies that have a lot of turnover in their employees. That's, that's difficult.
That's really difficult. It is. Well, there's, there's no questions.
No questions have come through so far. So I think you've, everything that, I think it was such a comprehensive presentation that I'm hoping it's got, it's got lots of ideas and lots of, tips and everything that they, the attendees can take back to, to their practise and to, to their farms that they're attending and hopefully spread some, good news and new information. So, I would like to thank Helen at the webinar vet for for doing all the stuff in the background for us.
And I get, I'd like to thank Jeff again for such a wonderful presentation. So I'd like to, and thank you everyone else for attending this evening. If you're in England, I hope it's probably a cup of tea time, and then for Jeff, I hope you have a lovely afternoon and you take care, OK?
You take care. Thank you, everyone. Good day.