Welcome to this presentation, examining how to minimise neonatal calf scours. Within this presentation, we're aiming to sort of look at a number of key topics around neonatal scours in cattle. So what we really want you to be able to do at the end of this presentation is understand the impact of enteric disease on calf health and performance, and then be able to logically, approach and investigate neonatal scar issues on farm.
And as part of that, we will focus quite a lot of our time on understanding the role of colostrum in calf health and how we can objectively assess, colostrum feeding practises on farm. And then moving on from that, I think it's thinking about how we can take steps to design preventative health protocols to minimise neonatal scours. So what is the impact of calf scours?
Calf scours is the most common disease in young calves, and it probably accounts for about 50% of all calf deaths in the UK. Calves affected by scour are most likely to die from dehydration, and that's because of increased fluid loss. But we also see, .
Scours either primarily caused by bacterial pathogens or bacterial pathogens gaining entry via damaged guts and then causing septicemia, which can also kill those animals. To put a financial finger on it, it is estimated that its scours will cost farmers around 44 to 66 pounds per calf, and, Majority of that cost is front front end loaded. That's going to be that cost of treatment and management and potential losses around those animals, but the long term impact of the disease should not be underestimated.
It will have an impact on growth rates and that future production and those animals. We're talking about dairy heifers, less likely to join, join the milking herd, and we're more likely to lose them at a later stage. And it has a significant welfare impact there.
There's pain associated with the disease, we've got the risk of mortality. And as we look to that one health objective, . If we think about sustainability and the responsible use of antimicrobials, scours causes mortality, which is going to have a negative impact on efficiency, which will then have an impact on sustainability, and the management of this disease is a key reason for antimicrobial usage on farm, and so there is that risk of emergence of resistance or that potential for irresponsible use and that's something.
As vets, we need to be making sure that we're approaching the prescribing of antimicrobials for the management of this disease, in a responsible way. So when we're talking about scours, it's a catch-all term and encapsulates a number of different pathogens. So we've got a number of viruses, so key ones would be rotavirus and coronavirus.
Key bacteria that we see causing diseases would be E. Coli and salmonella, and we also see Clostridia, as well as a bacterial cause. And then we also have Protozaurus, so cryptosporidia early on in life and then Coxidia slightly later on.
It is important to remember that ultimately we can see scour-like symptoms, so that upset of the digestive tract associated with nutritional changes, and so, it is important when we approach, an outbreak of scours and we're working with clients that we are making sure that, feeding is being undertaken in the correct way and that we rule out any nutritional issues at the same time. If we look at the surveillance data, what are the pathogens that we see most commonly in within the UK, and this is data taken from the APHA and SRUC so through the BDA system, and this is data for 2023. So over that period of.
12 months, diagnosis for neonatal and pre-weaned animals. We can see there 6 of the key pathogens that we're talking about. So coronavirus, rotavirus, E.
Coli, crypto, salmonella, specifically salmonella Dublin, and then coxsidiosis. And we see all of these diseases relatively frequently. But in terms of the most common diagnosis, cryptosporidia is still there as that sort of key pathogen that we're seeing most frequently diagnosed through the APHA surveillance data.
As we said earlier, ultimately, the key thing that causes the calves to die is dehydration, so that loss of fluid, . And it, because of this, I want to take a little bit of time just considering how we manage that on farm and then also the key opportunities for vets to engage with that with their clients. Because ultimately, that rapid intervention with fluid therapy is key, and I think we shouldn't underestimate .
The negative impact that it has if we're leaving the calf until later on in the disease process to start fluid therapy. If we can work with our clients to rapidly identify calves in the early stages of disease, where they are still able to offer additional electrolytes, . Fluid therapy in the form of oral fluids, we can hopefully prevent the progression of the disease down to that point where the animal is critically ill, and hopefully reduce the likelihood of mortality.
Ultimately, all electrolytes should be only given when the calf is still able to suckle. If the, we get to a stage of the calf losing, its suckle reflex, it's probably necessary to, start off the fluid therapy, at least initially with IV fluids. Again, with the electrolytes, it should be making sure that our clients are aware of the fact that they should be giving the electrolytes as additional feeds and that we are still offering milk, so we've moved away from .
The old principles of trying to rest the gut, and there's a wide body of work now that really acknowledges the role of maintaining calories going into the calf. We don't want to be starving them, but we need to be looking at how do we, bring in additional fluids. So maintain the sort of offering of milk feeds, but then add in additional electrolyte feeds is probably the key way to go.
And. One of the things that shouldn't be underestimated is the amount of fluid loss, and I think that's probably the common thing that we see as a challenge on farm, is that people view. A single 2 litre electrolyte feed as fluid therapy for the calf, and actually it's working with our clients to make sure we've got protocols in place that truly address both the deficit that the calf is at the point it's diagnosed, but then also the ongoing losses from that point of view, because if we take a, A 1050 kg calf with a 10% .
Deficits, or 10% dehydration, we're already 5 litres behind, and that's not factoring in ongoing needs and ongoing losses. So a single 2 litre feed of electrolytes doesn't go a huge way to addressing everything. So we need to build in programmes where our clients are prepared to feed multiple times with electrolytes and are managing their expectations that that single 2 litre feed is not going to be sufficient.
And it's. Useful skill to . Spend time with clients, enabling them to diagnose dehydration, so going through the idea behind skin tents, thinking about how they can rapidly identify those signs, but also getting them to think in a sort of proactive way.
Think about when are the stress periods going to be for these animals. So if we are, dealing with calves being moved through markets or through collection centres and then transported, those animals we could probably work on a. An assumption that they will be an element of dehydration there just because of the way that they have been, managed and sort of handled in that period away from farm and transport.
And so actually there's. Increasing evidence that actually bringing in proactive electrolytes on arrival at farms, as they sort of come in and welcomed into units can really help sort of stave off sort of progression of disease issues and put the calf in a good state of health to sort of adjust to this new environment. And getting our clients to look at it in that way can ultimately help promote the best quality welfare for the animals, but also can help us sort of, Prevent disease progression.
Ultimately there's lots of different oral rehydration solutions out there and. It's a good thing to sort of be able to have a look at them, provide good good quality advice around them. And what we're looking for within those oral rehydration solutions is that ultimately, we need them to supply sufficient sodium to normalise the ECF volume.
And as a guideline, probably 90 to 130 millimo per litre is suggested as being sufficient. If we're looking at low sodium products, we have to be really careful because they will not be capable of correcting the dehydrations. And then ultimately, we can go too far the other way.
We're actually giving too much salt and so too much sodium can delay a nasal emptying and cause ileus. And so we sort of see those sort of cars with the distended guts and sort of, and we see problems associated with that. We need to provide agents such as glucose, citrate, acetate, propinonate or glycine that will facilitate the absorption of sodium and water from the intestine.
And so, and those need to be there in the right ratios. So if we're looking at glucose, we need a ratio of glucose to sodium between 1 to 1 and 3:1. And if we go greater than that, we actually run the risk of actually causing an osmotic diarrhoea because we've almost got that sort of that draw, draw out into the guts and causes more problems.
We're also looking for those oral rehydration solutions to provide an alkalizing agent, and these can be acetate, propionate, or bicarbonate, and those are there to primarily correct the metabolic acidoses we frequently see associated with cask hours. And different agents have different properties and have different advantages, so. Acetate and propionate facilitates sodium water absorption in the small intestine, whereas the bicarb won't do that.
The acetate and propionate will also act as a, an energy precursor, so bringing in that additional, aspect there, . And they will also have an impact on the Abimazal pH. So there is a use for bicarbonate, and I think ultimately bicarb is a very good way of correcting the metabolic acidosis, but there is a reason that we don't see it in all products because actually other ingredients can have the same, same impact.
And ultimately, we also want that oral rehydration solution to provide some degree of energy. We know that it's not going to be as good as milk, but providing some energy there is going to be key to maintaining that calf's ability to fight off disease and hopefully stay further protect sort of progression of the disease process. So if we've got a calf in front of us, all rehydration is gonna be the key thing.
Other treatments we should be considering and thinking about. Antibiotics, the use of antibiotics is always gonna be controversial, and we need to think about how we approach our antibiotic prescribing for . Calf scours, it needs to be evidence based, and we need to do so, we need to be prescribing it in a responsible way.
That said, we need to remember that there is a strong bacterial component potentially there for scours, so studies have shown 20 to 30% of systemically ill calves will have a bacteremia there, and so in a an antimicrobial will be indicated in those situations. We also have that risk there that ultimately. Because of the primary damage that goes on, we often see an E.
Coli overgrowth in the small intestine. And so, again, another driver for us to potentially look at prescribing antimicrobials for these cases. If we're looking at how does this translate to advice to our clients on the farm, I think ultimately we shouldn't be using antibiotics as the go to immediately we see scours, we should be using it as in, in a targeted way.
So thinking about how we draw up treatment protocols that may be based on the the presence or absence of . Pyrexia. So if the calf is pyrexic, it may well be worth that we are introducing a antimicrobial at that stage.
It may or may be that we start using it where we've got animals that are showing severe depression, again is an indicator for using it. But it is a, an area that we need to work closely with our clients to get them away from instantly using antibiotics for every single case. When we're looking at products to choose, ultimately, thinking about the pathogens that we're dealing with, we should be looking to target E.
Coli and also potentially the salmonella species. Alongside the antibiotics, there is a role for non-steroidals. Diarrhoea is often accompanied by intestinal cramping and abdominal pain.
So there is an indicator there for analgesia. The non-steroidals will reduce inflammation and can reduce the effects of endotoxemia and septicemia. And they will also help improve intakes and also increase weight gain.
Alongside those treatments, it may be the situation where we also look at specific treatments for diagnosed pathogens. So if we've identified cryptosporidiosis, we may be looking at products such as halouginone and being very targeted in those ways, but that will be dependent on, what we have found diagnostically. So how do we approach an outbreak of scours?
So an scour outbreak is gonna be associated with many different factors, and it's gonna be that overlap between the immunity of the calf, the the the pathogen. What the pathogen is, the pathogen load, the level that it's there at in in that case, and also the impact of the environment, and that environment can impact in a number of different ways. That could be down to it causing stress on the individual calf, so therefore negatively impacting on the immunity.
It could be the fact that actually the environment is the source of that pathogen for that calf. If we think about all of the diseases that we're talking about here. In terms of, neonatal diarrhoea, the root of infection is the faecal oral route.
So it is all about how do we minimise that, the sort of the pathogens going via that route into the calf, and so the environment will play a key role to that. So. As we now move forward and we start thinking about how are we going to approach an outbreak of scours, so we've triaged our individual animal, we've provided therapy, but we're then gonna look at, right, how do we take a step forward?
How do we investigate this? How do we identify risk factors, and how do we, instigate preventative measures. We're gonna sort of look at these kind of things.
So we'll look primarily at the sort of the immu immunity when we consider . The colostrum, and then we'll also sort of think about the roots at which that pathogen is gonna get, get to that animal, so be that via the the environment or by feeding practises. So, There's always the question when we think about scours, and I think if we're considering that pathogen, does the timing tell you anything about the likely cause, .
There are Sort of various bits of dogma out there in terms of, well we see E. Coli early on, along with the rotavirus and coronavirus with . Other, other bacteria coming in slightly later and then sort of the crypto and the coccidia even later than that.
And yes, there is some patterns there . And this sort of table summarises sort of some of the general thinking around this, but I think it's really important that we do not rule in or rule out pathogens solely based on the timing that they, they are. There are so many factors at, at, at play, and some of that will be down to.
The level of challenge that we're dealing with, the stresses the animals are dealing with, we also have to bear in mind, especially on farms where we don't necessarily have a consistent population, so if you're dealing with a farm that is buying in calves, then actually, Some of this will go really out the window because we could be introducing calves to new pathogens that they've never seen at slightly different ages and, and when they are stressed out themselves post transport. So actually, you may well see some of the sort of diseases that we see very early on that little bit later. So, have it in the back of your mind.
It is a useful guide, but I, I would encourage. Caution around it and there is a huge amount of overlap and probably what does this highlight that actually there is a real importance to the diagnostics. And It is impossible to tell the exact cause of scars based on the clinical signs and the nature of the scar alone.
It's, it's often the case that you'll go on to farm and the farmers will, they will believe that they've got a certain type of scar based on the characteristics of it, but I would discourage that. We are in a position where we have a number of rapid diagnostic kits now available for that on-farm diagnostic, so, . Similar to the one in the photo on the right hand side, and these can provide rapid, rapid results for a number of the pathogens, so rotavirus, coronavirus, E.
Coli, crypto, within, About 1015 minutes, so it can be really useful for that. For salmonella, we are still reliant on culture as the, the really sort of way forward, so that will take further diagnostics and will take a little bit longer to get the results. And similarly for sort of things like coccidiosis, we are more dependent on microscopy for that, but.
Having those rapid diagnostic kits are, it's a good way of engaging with clients in this, it allows us to get a quick access relatively cheaply, to some diagnostics that really can help illustrate what the pathogens are. And it may well be that actually those pathogens aren't gonna change what we do specifically. So actually we've got an outbreak of scars and it's caused by rotavirus, coronavirus, and to some degrees sort of the colis, actually.
The mainstay of those treatments is going to be around that fluid therapy and that management of those individual animals, and sort of doing everything we can to support them. Antimicrobials if appropriate, and that may be introduced as a way to either manage a bacterial cause or if we've got a bacterial causes a secondary infection. But the information about that diagnostics will potentially help us make a decision or guide further control measures in the future.
So, when we consider things like rotavirus and coronavirus, it will be about whether or not we can look at potentially using vaccination programmes to, facilitate control and boost the immunity that those young calves are receiving from their dam's colostrum. So We've got a diagnosis potentially. We're, we're faced with this outbreak of scours, we've managed the clinical cases.
Where do we go next and how do we approach the problem? And I think it's really important that we take a step back and do not just focus on the calf in front of us, look at the process that the calf has been through. So, where does that calf come from?
We may be on a situation with a car where ultimately it's brought in, so we don't have access to information about the colostrum and that's not being controlled by the farmer that we're working with. In those circumstances, it will be much more about, we know that we can't control that, we can look at how we take the stress out of the process of those animals arriving onto the unit, but. We aren't gonna be able to delve too deeply into the colostrum management on those farms or what went on in the dry period of the cows.
So in those circumstances, the discussions probably are going to be limited to about what we're. What we're getting our clients to do and think about when they're sourcing animals, so what questions are they asking about colostrum management, what questions are they asking about disease status of the, the calves that they're buying in. On a dairy farm, however, what we actually have the option of is sort of taking a step back and sort of going further back in that sort of the life cycle of that calf.
And really it's important that we go right back to that beginning. So go and have a look at the dry cows, look at the calving pens, look at the calf equipment, and in those circumstances, we're looking A for the sort of the management of those animals in that situation. So what's the health status like for them?
Are they in good condition? But we're also gonna be looking at that hygiene piece, so if we again if we're thinking that route of infection is coming through the faecal oral route, if we are looking at calving pens which are filthy dirty, which are leading to other contamination, and the calf is then going and being left to suckle on the udder. In those circumstances, what are we gonna get?
We are going to get that first meal, that first intake that that calf takes is gonna be potentially of scour causing organisms. So again, it's looking at potential control measures around that and. Above all else, when we consider that that step at that point, we are gonna be looking at the colostrum and what goes on with colostrum management and how that sets the calf up for its future performance and its future health and productivity.
There are a number of cues around Caloster management and I think they've come about as a way of really driving farmer engagement with the importance of this topic, and we'll use this as a, as a stepping stone so that we can sort of look at the key areas. And probably. The three cues that if we asked anyone to think about would be the sort of the quality, the quantity and the quickly.
So focusing on the quality of the colostrum, how much colostrum those calves are then getting and how rapidly we get that colostrum into the calf. But increasingly we are seeing additional cues, added into the sort of the things to to consider and actually from a veterinary point of view, I think these offer a great way of us engaging. Especially around the quantify, so what are we doing, either as vets to look at failure of passive transfer and monitoring whether or not we have that there on farm as a challenge, but also thinking about how we can work with our clients to monitor colost quality and.
As we promote higher standards of welfare and that there is that greater understanding of the impact of stress. It's us looking at the process the calf goes through and making sure that actually as we are asking our clients to ensure that they are getting sufficient quality colostrum into that calf quickly enough. Are they doing it in a stress-free way?
What's going on in terms of that management of that calf? Because ultimately stress and the cortisol associated with it will have a negative impact on, on the sort of the development of the immune system for the calf. So, if we consider those 5 Qs, what are we looking for around the quality, .
We're looking for that to be, have sufficient immunoglobulins in it. So, we want good quality to have greater than 50 grammes per litre. We also want to make sure that that colostrum isn't contaminated.
So, we do not want bacterial contamination of that because that will act as a source of infection for the calf, or B, interfere with the absorptions of the immunoglobulins. So. If we were to quantify that, we want to look at that being less than 100,000 colony forming units per mil when we consider their total bacterial count.
When we consider quantity, we're aiming to get 10 to 12% of a calf's body weight of Calostra into that animal, so . That then equates if we're taking good quality colostrum into about 150 to 200 grammes of IgG. So that's the target, that's what we're wanting to do.
And because of the nature of the calf's gut and how it develops immediately after birth, that we, because we have that change in the sort of the, the, the ability of immunoglobulins to pass through the gut. Starting from the very moment they're born, where actually we have the channels where the the immunoglobulins can pass from the, from the intestines and from the stomach into the bloodstream, but those rapidly close off and so we, we have a very finite window whereby the, the calf can absorb the immunoglobulins. We need to get that colostrum into the calf quickly.
And that, so we're looking at getting that ideally in the 1st 6 hours of life. It's also important to remember that when we're talking about quickly, it's about when are we harvesting that colostrum from, from the, from the dam, because that first milk immediately post calving is when it's going to be at that sort of the highest quality point. So it is about getting the best quality colostrum from the dam and getting into that calf as quickly as possible.
When we're talking about the immunoglobulins, what is it in Colostrum? So colostrum is primarily made up of sort of IGG with in terms of immunoglobulins, so that probably equates to about 80% of the immunoglobulins there. And of that, IgG 1 is pretty much the dominant one, so it makes up about 95% of the IGG and that's gonna be transferred.
From the dam's blood by the mammary epithelial cells. It's quite a small molecule, so it can move in and out of the blood pool. We then also have IGM and IGA and these are sort of their slightly smaller percentages, so IGM about 10 to 15% and will remain in the bloodstream.
And then we also have about 10% of the total immunoglobulin made up of IGG and that's going to be responsible for a lot of the surface immunity that we see. Traditionally, the focus with Colostrum has always been about the immunoglobulins, and that's, rightly so, a key driver of the immunity of the calf and it's something that, farmers are increasingly aware of. We've seen some great campaigns, through the farming press and through farming bodies around things like colostrum is gold, and really instilling the importance of getting that colostrum into the calf very rapidly right off from the start.
But it's important to believe and to remember that ultimately colostrum is not just about the immunoglobulins, it's a source of a number of other key things that can help . Promote that early stage development of the calf and that sort of development of the of the gut and the and sort of are key to the long term performance and so we have insulin and insulin like growth factors, cytokines and hormones, vitamins and minerals, we also have neutrophils and macrophages and a new modulating factors. So a number of different components there that all go and sort of work as part of that .
Sort of key drive in terms of improving the. The sort of health and welfare of that calf. And the table here really illustrates that the difference that there is between milk and colostrum.
So if we look at the first milking on the sort of the left hand side of that table, that's what we're talking about when we've got that colostrum. So that 1st, 1st collection there, and you can see when we compare that to the right hand column which is milk. The sort of how much thicker sort of the percentage of solids that there is in that colostrum.
And that's made up of a large amount of protein, so, and be that sort of immunoglobulins, but also other proteins. We've got a higher fat content, we've sort of, all those kind of things that ultimately really demonstrate that colostrum is this really important start off in that calf life and when we're considering a disease outbreak in something like neonatal scours, which we're talking about happening in the first couple of months of life. Colostrum and it's the ensuring that that if they've got that is often one of the key areas to consider because if we do not get this right, we are gonna be fighting against it when it comes to disease control later.
So how can we monitor it? And I suppose we can look at Colostrum and the monitoring of failure of passive transfer in a number of different ways. So we can look at the calf itself, so we can take blood samples from the calves, and ultimately at that stage, what we're doing is we are assessing the end user of the Clostrumm, and so that's gonna be.
A, an indicator of how well we have achieved that colostrum feeding and our targets around that. So have we got the right quantity of the right quality colostrum into that calf quickly enough? So it really is that sort of assessing whether or not we've got that transfer of passive immunity going on.
We can also measure colostrum and look at colostrum quality, that is. Practical tool, easily done on farm either with a refractometer or a colostrometer as shown in the picture here, and I think that is there as a way of assessing the quality of colostrum. So it's only gonna give us an idea of one of the cues.
It doesn't nece it's not gonna give us an idea of whether or not we have successfully delivered that colostrum into the calves. But, it's still a useful tool, so it, it can form part of management procedures, so people will be, measuring the quality of the colostrum to ensure that they are, what they feed to calves is hitting the right, right level of quality. We also have people that will measure the quality of the colostrum if they're going through processes such as, pasteurisation, so.
Pre and post pasteurisation samples can be a, a useful tool of making sure that we are not having any adverse effects on, on the immunoglobulin content of those, . So it is a useful tool, and it can sort of help drive that problem, but it doesn't necessarily give us sort of that indicator of how successfully we delivered those immunoglobulins to the calf. When we're considering it on farm at a farm-based level, it is important to sort of understand some of the challenges around it, so colostrometer's a quick and easy tool, very fragile, but all we're doing is measuring a, an indicator of the sort of specific gravity of that colostrum and using that as a surrogate for the immunoglobulin concentration.
But when we're doing that, it's important to remember that. Things such as temperature can have a really big impact. And so if we're measuring outside in the calf shed in the middle of winter, we can actually get to a stage where we would see colostrum reading a much better than it should be because that low temperature means that we will overestimate the amount of inogos in there because of the impact of the temperature, on the, on the liquid.
For the next few slides we're gonna focus on passive transfer and. I think from that point of view, what we're sort of really gonna be looking at is sort of what's what's going on. With how we've successfully delivered our colostrum to the calf.
So we can do direct measurements of IgG, or, or a total immunoglobulins, and that's possible on blood samples, so they can be sent off to labs and if you read papers around that, there are various different, . Laboratory testing techniques, . For that, we are, we are at a stage where actually there are commercially available testing for RID, so radio immunodeficient, diffusion testing of colossum for IGG.
So it is possible to, to use these commercially and sort of get a proper reading of calves and see what we're getting in terms of the IGG. That said, probably what we've got to within sort of the, the monitoring failure of passer transfer is that we are focused now a lot on . The sort of the use of indirect measures, so things like serum total proteins, so we're using those as an indicator because they can be done cheap and easily on farms.
So it's important to understand that we are presented with lots of different testing techniques, . And it's picking the right one for what you're wanting to do. In depth, in-depth investigation of specific cholesteral issues, so that might be to do with concerns about the efficacy of pasteurizers, or what's going and those kind of things will require lab testing, whereas actually it is possible to use things like .
ZSTs, total proteins as a way of sort of doing a much broader check on the the sort of, Immunoglobulin status of the calves and give a sort of herd level picture, which is probably sufficient for a number of the disease investigations that we're gonna be involved with. So what are we doing with total proteins? Ultimately it's used as an indirect assessment of colostrum intakes.
It is highly correlated with serum IgG levels, but it is important for us to remember that there are a few key caveats that ensure that we get that correlation. It can be done on both serum or plasma samples, and ultimately it is cheaper and quicker than sending off to a lab, so this is something that can be done. Effectively on farm or certainly just on straight away back in the practise, results can be within a few minutes and we can, we're talking about a few pounds just to get it done.
and this can be either done through specific gra gravity, and looking at the sort of total proteins through, refractometers, and that can either say, either reading in total protein and and specific gravity or looking at the, the bricks reading as well. And there are. Well published recommendations around this, so this is table summarises the results from a, Expert opinion forum, a few years back in the US where they considered what should we be aiming for in terms of colostrum feeding.
And if we were to assess the colostrum feeding practises on farm, what is achievable, and, what should be aspirational for people to achieve. And so this sort of . Table sort of summarises what we have in terms of that serum level, so what we're trying to get to with the serum IgG, so grammes per litre, so excellent being above 25 and then going down to being less than 10 as a sort of indicator of poor and absolute failure of passive transfer.
And then they tallied to that with to what that equates to in terms of serum total proteins, so. Above 6.2 for excellent and then going down to below 5.1 for poor, and then alongside that we have what that equates to in terms of the BRICS percentage and.
They've then came up with sort of guidelines as to what percentage of calves we should see in each of those categories. So, ideally we're looking for greater than 40%, in the excellent category, and ultimately, I suppose we're sort of, we should be striving to keep that number ever increasing, and I suppose that's one of the things when we start putting guidelines on sort of excellent, good, fair, and poor, is that it's important that we make our clients are sort of aware that we really should be striving to. To get as many as possible into the excellent and it's not about just hitting 20% in fair, 30% in good, and 40% above that, we should always be striving to get as many as we possibly can into excellent and avoiding as many, avoiding having any in the poor, and.
The right hand column there gives an idea of what the sort of percentage of calves they found into on-farm surveys is. And so probably the key thing there to look at is that 12% figure in the sort of the bottom row where we've got 12% of calves coming in as being very poor in terms of colostrum quality. As I I highlighted previously, there are issues with total protein.
Yes, it has the benefit of being cheap, and it can be rapidly done. The cheapness means that it is, is easily adoptable as one of those tools that we can do on a large population of animals, we can do frequently. But it does assess all of the proteins in the bloodstream and so 35 to 50% of that will be .
Albumin, and that level will be relatively stable. It does give us an indicator of the IGG but also the IGM and the IGA so there will be a little bit of a variation there because of the IGG but we know from previous slides, when we're talking about the IGG it's making up about 80 to 85% of that that figure anyway, and there are other immunological proteins there. I think the key things to remember is it is affected by dehydration, also inflammation in the age of the calf, so we have to be very targeted about which calves we're sampling.
And if we've got a dehydrated animal, or a sick animal where. Ultimately, we will see this, the, the total protein rise, and so that will give us an abnormally high reading which is almost sort of counter what has actually gone on because I say we, we, we could actually see an animal that had truly had failure of passive transfer. We take samples of it when it is in a situation where it's dehydrated, and sick, and actually the total protein result would come back as showing that we didn't have any failure of passive transfer there.
So it is important that we, we are selective about what, what we're sampling. So Make sure you're choosing the right calves, so calves under one week of age. We don't want to be going too early, so we want about 6 hours after the colostrum feed for the absorption to have taken place.
And so in an ideal situation, we would be aiming for 24 to 36 hours of age. Realistically, that's not always going to be possible, but it is, if we're looking at taking samples, we are needing to be doing almost on a weekly basis on a herd if we are doing it so that we are capturing calves at the right ages. We should be able to say, avoiding.
Any sick animals, so there should be no evidence of clinical disease or dehydration. Calves need to be representative of the group, and so potentially it is thinking about excluding animals that are twins or calving difficulties or making sure that that we know that those complicating factors are there for those animals so that we're aware of, anything that potentially could have an impact on the readings and results. And Because it's a herd level indicator, we're not using total protein as an assessment of an individual calf.
We're using it as a way of monitoring failure of passive transfer on that farm and work has been done extensively in this area and. A lot of it gets done in the US and Canada where we're potentially doing, dealing with larger herds, and I think sometimes that can present a challenge in UK systems where. We may only have one or two animals calving a week or we might, because of the age limitations we we only have a limited number of calves to sample at each sampling point.
And ideally you're looking sort of for that sort of 20 calves sample to give you a good number, but probably a minimum of 12, and it may be a case that actually this is going to take a number of sampling, . Time points to get that on, on some dairy farms in the UK so don't be afraid of taking samples over multiple time points. And this is where having that sort of background information, setting up programmes where it's being monitored regularly can really help.
But it is, it's a useful tool, and despite all the work that we see done, encouraging people, the fact that. Colostrum is constantly being talked about in farmer meetings, in the, in the farming press. We see, industry initiatives around it.
It still remains a significant challenge on farm and the sort of data is there, in the right hand table about the sort of the failure of passive transfer prevalence. So if we think back to what was put up in the, the table from the US, which was probably about the sort of 12 to 14%, which sort of, equals what was found by Hagerty atal in 2021, . There, there has still, in other studies shown anything around 20 to 25% of animals with failure of passive transfer.
So this remains a big area that there is potential for improvement on, on, on farms, so engaging in this topic, especially when you're dealing with outbreaks of things like scours is gonna be key to its success. And why are we focusing so much on Colostrum? We've come into it within this presentation as one of the key reasons why we see outbreaks of scours because of that, it's important in terms of the, the neonatal calf's immunity and the protection that it provides that calf against disease in the first few weeks of its life.
But the long term ramifications of poor coloster and feeding are also well documented, so. This table summarises some of the key pieces of research around the long term effects of colostrum, so low in here is sort of poorer quality colostrum, so equivalent to sort of failure of passive transfer, high is where we've got good quality colostrum, we've achieved a good level of immunoglobulins going into those animals, and we can instantly see the positive benefits that colostrum feeding brings. So that increase in the weight difference, so we've got.
If we get sufficient colostrum into those animals, we're gonna have nearly 30 kilogrammes of extra weight by 205 days. Live weight gain is, is greater. We're reducing that age of slaughter if we're dealing with beef animals.
The veterinary costs per calf are decreased significantly if we make sure that we are getting good quality colostrum in and. All those factors, especially when we're talking about growth rates, when we've talked about the resistance and resilience to disease equate to really significant . Differences when it, when we start looking at the lactation yields for these animals.
So if an animal has had failure of passive transfer and we've failed to get sufficient immunoglobulins into it, we are potentially looking at 1000 kg deficit in milk yield in the first lactation, and that is never actually properly recovered, so those animals are much more likely to end up as lower yielding animals, longer term. We then see also issues around this sort of long term survivability in the herd, and in a state that we are now in where we are looking for efficiencies, we are looking to drive the performance of our stock, minimise disease, promote health and welfare without having to intervene. Closter management still remains a core core aspect and something that we should be really focusing on and ensuring, as we highlighted within that sort of circle with those five cusqua, that it is something that is regularly being assessed.
So thinking about how are we quantifying it and how are we looking at it on a regular basis. So We can look at the calf, we can look, as we said, we can look at looking at a group of animals to look at what's going on in terms of failure of passive transfer. And so if we're faced with an outbreak of scours, we may have treated and managed a group of animals with some scours there.
We then may be ending up having to look at some younger animals so that we are then assessing what is going on with the colostrum feeding practises, and so the success of, of how well. The, the colostrum feeding programme is, is, is being followed, and so that will be us looking at younger animals, seeing what level of failure passive transfer we get through those animals and using that as a marker of the sort of colostrum feeding. It's also important that we look at the techniques around that sort of colostrum harvesting and storage.
So there is risk at this point of introduction of bacteria. So if the other is not being properly prepared, as we said before, if we've got the cows being kept in a dirty calving environment. There is that potential for bringing in bacterial contamination into the colostrum.
And Moving on from there, if we get that bacterial contamination, if that colostrum is not being stored properly, so it's not being quickly chilled, it's not being refrigerated, it is staying longer in a fridge in a fridge than it should do, so maximum should be, we shouldn't be having colostrum in the fridge for more than about 5 to 7 days. If it's, we then run the risk of. That bacteria growing within that lostrum, and we said before, that bacteria represents a challenge to those animals, either as a pathogen in itself causing disease, or as something that is gonna interfere with the immunoglobulin absorption, .
Through the gut of those cars, so. Always check the Colostrum harvesting and storage. Don't just ask the questions, go through, look at the equipment, look at the process, ideally observe it.
You can take samples, so actually in the same way as that you would take a bulk milk sample to check for TBCs or. Coli counts, you can send a sample off, from the colostrum to, to measure bacterial contamination, and that can give a good indicator. But look at the procedures for collection.
Look at how it's being stored, but also look at how it's being administered. So how is that colostrum getting into the calves? So what's going on in terms of how rapidly that's happening, but also look at what's going on with the feeding equipment and how well kept and how clean that is.
Because Colostrum is. An ideal medium for growth, you can see there . On the, on the sort of slides on the right hand side, how rapidly we see an increase in bacteria.
Over the space of 6 hours, and that's just colostrum left out at room temperature. And so it is a great medium for bacteria to grow in, so we do need to be making sure that we are doing everything we possibly can to minimise contamination in the first place, but then also put it in an environment where it is not going to provide the sort of the. The correct sort of temperature for, for bacterial growth.
Yeah. Moving on for Colostrum, I think it's important that we then look at other aspects where we potentially are seeing. Contamination or we are seeing ways in which the pathogens that can cause scour are gonna get into that calf, because if we approach any disease investigation, what are we trying to do?
We need to look at. What disease causing pathogen we're dealing with? Having done that, it's then going right, where's that coming from?
How is that pathogen getting access to the animals that we're dealing with, how is it getting access to that population? We've also already alluded to that ultimately with scour pathogens, it's all about the fecal-oral router transmission. So if we've got an outbreak of scours, and we're dealing with milk fed calves, it's going right, how are we getting?
That pathogen into those calves, where did it come from in the first place? Was it picked up from the calving environment? Was it picked up from the calf shed and one another animal, and moving on from that, it's then going, how is it being spread and what are we doing to reduce the chance of that spread, so.
Looking at anything that goes in the calf's mouth is really important, so considering feeding equipment, looking at how that is maintained, looking at how that is regularly cleaned, where it's stored between feeds, so thinking about, like, if we look at the picture on the right hand side, we can instantly see that there's potentially faecal contamination on that feeding unit. Big bugbear of mine is when we sort of see calf feeders washed out and then left on the ground to dry. You can imagine that we're doing something right, we are cleaning those, but then we are potentially getting to the stage where we then get contamination being picked up from, from the environment again, so.
Consider what is going into the calves mouths, what is the potential for bacteria, viruses, protozoa, a get on there, and then also sort of stay on there, so what are we doing to minimise the chances of spread? And. It's drilling into clients about maintaining the high standard of hygiene, and I think.
It's very easy for people to to look at this in a way that they, this is how we've always done it, we've always just rinsed out the buckets and then just put them on the floor. I think a good way of engaging with, especially with dairy clients around the importance of hygiene is thinking about what they do for, for milk production, what they do around the parlour. The parlour is that key piece of kit and that key thing they're doing twice daily where they are very .
Bought into the importance of hygiene, what chemicals are we using at what time and at what temperature to achieve that sort of proper level of cleaning. And then if you compare that to often what goes on with the calf feeding equipment, there's this big gulf between them, and actually, they should be viewed in the same, same way. We should be having a.
A a process there for our feeding equipment, be that preparation or be that sort of actually feeding itself, that is very similar to what we would be doing for washing down the parlour. So what are we doing around rinsing it? What are we doing around detergents, allowing it, and then rinsing off again and then allowing it to dry properly, and having a protocol there, getting them engaged with it and getting people to think about it as in the, in the sort of.
In the same way that they look at their milking equipment can really help, because I think all too often on farms we come across sort of things that we're then we're presented with that actually are not up to standard and actually need to be scrubbed better, and so in spending time working through clients and having a, a, a cleaning protocol in place is key. Alongside the cleaning of the feeding equipment, it's important that we also think about what we're doing around the milk feeding. We alluded to, at the start that actually scours can be associated with nutritional issues and that sort of change in diets can be one of those things, but.
If we consider what we're doing around stressing an animal out, and the potential for disrupting, it's digestive system, it is important that we have, Consistency and attention to detail. And if we're looking at feeding practises, what does that boil down to? We've mentioned already the importance of cleanliness, but we should also extend that to look at what is going on around the temperature and how that milk is being fed, what's going on around the volume and availability, when is it fed, so the time of feeding.
But also thinking about how that milk is prepared, and ideally what we should have is a, a very consistent feeding regime. Following the guidelines given on the packaging of what should be a very, a high quality milk powder, and we don't have time within this sort of session to go through the quality of the milk powder, but I think when we're looking at. Disease outbreaks and things, the starting point before you do anything else or even start criticising the quality of the powder is look at the human factors around it.
What is going on in terms of the the way it is being fed? How is it prepared? What is being done in terms of the temperature?
One of the big variations we often see is the challenges around concentration, with people not necessarily weighing out the correct amount of milk powder to water, and so that can lead to variation between feeds, can lead to variation between operators in terms of what goes on. So think about that and look at what goes on that and sort of an area that you can be easily focused on and walk through with the client. And There should be a feeding protocol.
And the way to look at this, it should be a set of instructions that means that anyone could walk into that calf shed, prepare the the milk feed appropriately, correctly, and feed it out to the calves. So it needs to give details about the concentration. How is that prepared?
What . What temperature, how much water is being added to how much powder. What we then, and then also thinking about temperatures and how it's being fed, but then thinking about also any other things that we need to be covered by the protocols, so things like cleaning, and having something there that people can check up on is really important.
So having it written down, cos that really can help reduce the challenges around consistency between team members. So one person is doing the same thing as another, then. That sort of because there is a recipe there for them to follow, and so it can be a very good exercise to to walk through that process.
And actually, in the, when we're considering this sort of investigation of calf scours. Going, again, going back to walking through the process of everything that is a risk factor for scours can be incredibly enlightening for you as a clinician. It's a great way to engage with the farmer on growth rates in terms of what they're doing, in terms of their feeding practises, but it's a really good way of sort of digging into finding out exactly what happens, so.
What's going on in terms of mixing, what's going on in terms of measuring temperatures, what's, how are things actually cleaned? Because if you stand around and ask all those questions in the space of 10 minutes, people will give you the answers that they think you need and you want. If you just ask a very closed question, are, are the feeders regularly cleaned, you'll get a yes.
What we're actually interested in is what's that cleaning process look like? What are we doing? Are we properly rinsing with warm water so that we're not getting a sort of build up of biofilms?
We're then going in with a detergent, because definition of. Cleaning will vary between individuals, so take the time, walk through the process, and then actually what that will allow you to do is come up with a number of protocols that you can then look at implementing as we take onto that step of how do we prevent future outbreaks. So we've talked about immunity.
We've talked about colostrum and the importance that that has in terms of giving that. Calf the correct start, providing it with the immunoglobulins it needs to fight off disease. Alongside that, we've talked a bit about feeding, we can, and that sort of feeding practise is there.
We need to make sure that the calves are getting enough nutrition to enable them to maintain the immune status that we've given them, but also we need to look at feeding as a potential route of infection. The scours The other thing to consider is always gonna be around cleansing and disinfection. And this will be at a number of touch points, so this will start with the carving pens, and everywhere that that calf comes into contact from that point.
So it's carving pens, it's how the calf is then transported from the carving pen. To the calf housing, so is that in a wheelbarrow, is that, in the back of a, in the back of a truck, is that just carried? Is it in a sort of calf trolley?
What's going on with that and how is that cleaned, but then it's also how well the the calf, the calf housing is cleaned as well, because cars will explore with their mouths and so if we have. Severe contamination of the environment that we're putting them in, we will get disease transmission. And so we need to also then be looking at the cleansing and disinfection of the buildings, and this is gonna require time, effort and commitment and those protocols need to be carried out, regularly to prevent that build up and.
Ideally we have buildings that are gonna be easy to cleanse and disinfect, but challenges we're often dealing with sheds that aren't necessarily purpose built for this in the starting point so aren't necessarily of . As easy to clean as we would like them to be, but. What we do need to do is make sure that we are following the correct steps.
So we are making sure that we are getting people to take out the faecal matter, all the sort of biological matter before we disinfect, so we understand the difference between cleaning and cleaning and disinfection, . We then need to think about what products we're choosing, we've identified that there are key, key pathogens such as crypto, such as Coccidia, which are, Going to be very robust in the environment, so they, they survive very well, so it is important that if we're dealing with outbreaks of those, that actually we're picking the correct disinfectants that are going to be effective against them and that we're then giving. Using those disinfectants at the correct concentration, and we're giving enough time for them to be active before we put animals back into it.
And some of the challenges around cleansing and disinfecting, especially when it comes to neonatal calf diarrhoea, is on an all year round calving herd, it can be that we just never have time for those sheds to rest. And so it may be that as we approach the management of this disease. Outbreaks, we're having to work with our clients to think, right, what is the alternative here?
Is there any anywhere else we can alternatively house some animals whilst they are, we cleanse and disinfect this shed. When can we give buildings a rest so that we can go through this process? Because if we're dealing with a ongoing scour problem, if we cannot get those buildings properly cleaned and disinfected, it's gonna be very difficult to put into place any other management, tools that are gonna be effective if we're gonna constantly have that environmental contamination that the calves are fed with.
Mentioned before that the importance of control of coxy and crypto and thinking about what we we have there in terms of . Products that we can use, number of different products there listed, this is what all work that's come out of them or done on what's actually effective against the US assists . It is so choosing one of those products, giving it enough time for them to be, be able to work, and to be effective, and making sure and stressing that point we need to get rid of the biological material first, because ultimately if we've got, if the eurocysts are there in a lot of faecal matter, that's gonna protect them from those disinfectants as well.
And remembering that disinfectants are best used when they're made up fresh, so they're gonna lose their efficacy over time when they're kept up in their working concentration. So make them fresh, use them at the appropriate concentration, and build this sort of cleansing and disinfecting into that sort of protocol is gonna be key. So In the last section, I just want to take a couple of minutes and sort of talk about.
How do we pull this together to think about where do we, we go from here and how do we prevent scours in cars? It starts at the beginning if we think back to that susceptibility triangle we put forward with immunity, the pathogen, and the environment on it. When we're talking about calf scours, a number of those pathogens are always going to be in the environment.
We're not dealing with pathogens that we are able to eliminate. We are dealing with pathogens that we must prepare a a calf. To face, and also that we can control the level of which, at which those pathogens are being exposed to the calf.
So we can't eliminate them completely, but we can reduce the exposure. So if we think about it from a point of view of enabling the calf to protect itself, so how are we gonna give that calf the suit of armour? That's gonna start with colostrum feeding.
And the colostrum feeding, as we've said. We will come from getting our dry period right. We need our our cows to produce good quality colostrum.
We then need to look at how do we get that good quality colostrum in enough quantity into the calf quickly enough. There is opportunity around that for us as vets to engage with our clients and when we're looking at sort of ongoing preventative cycles and. How do we .
Maintain the sort of forward progression on farm, monitoring failure of passive transfer, monitoring colostrum quality, there are tools there and these are things that we can get ahead of the curve and sort of right, if we're doing these on a regular basis, we can maintain that focus on colostrum and the benefits of it and sort of make sure that we are constantly striving to maximise the number of animals that get sufficient colostrum quickly enough. We can look at vaccination for some of the pathogens, so we're in a position now where we have vaccines there for rotavirus, coronavirus, E. Coli, and more recently also with crypto, and these are vaccines that.
Will work by promoting pathogens specific immunity within the Clostrum, so these vaccines are given to the dam during the dry period to promote production of immunoglobulins specific to those diseases. So those offer a good tool for us to provide the calf with the best possible start. We do need to make sure that the clients are fully bought into the importance of colostrum feeding for the delivery of those those immunoglobulins to the calf.
So if we're going to go down the line with vaccines and one of the things to, to keep a focus on is how good is the colostrum feeding, then afterwards to make sure that the calf gets what is required. And so. Again, that feeds into that sort of quantifying colostral feeding, so alongside vaccination programmes, it's thinking about how are we ensuring that the calf is getting what it needs to make sure it has the protection.
We want proper nutrition, and that's gonna be there both to provide the calf with the energy it needs to grow. Provide the energy it needs to mount a defence against any diseases, but then also, making sure that nutrition is delivered in a consistent way that actually we're not disrupting what the, what's going on in the calf's digestive tract about what we're doing. And we want to think about how we minimise stress.
So what are we doing to that calf to sort of make sure that we are. It's not exposed to undue stress which will have a negative impact on its immune system. And we want to make sure the environment is fit for purpose, so again, it's, it's protected, it's warm, it's out of draughts, it's a clean environment.
We then take a step back, it's then going right, OK, I've got that calf. It's set up to protect itself as much as it can be. We've given it the Colostrum, we've boosted the immun immunoglobulins available to it by through .
Through Vaccinating the dams and then feeding that colostrum, but how do we minimise exposure? As I said, we're not going to rule exposure out completely, but we can. Provide that, that calf with extra protection and sort of make sure it's not being exposed to an overwhelming challenge.
And some of that will come down to biosecurity, so thinking about what's going on on the farm as a whole, so diseases such as salmonella, what are we doing to keep those out? But it's also thinking about the calf as a high risk animal on the farm. So what are we doing to.
Reduce the potential spread from. Adult cows to the calves. And so what are we doing around the calving area, but then also what are we doing about the movement of people, movement of machinery between the rest of the herd and the calf rearing areas, because there will be pathogens that, as we said, we acknowledge that most of these pathogens are, they're going to be in the environment or they're going to be carried by healthy cows.
That potentially those calves could pick up and so we need to think about what we're doing to reduce the potential for that spread, so that can be down to biosecurity at those points, foot dips. Different overalls, thinking about that kind of how do we. Reduce that potential spread.
We need to think about what we're doing around management, so how regularly we cleansing and disinfecting our calving pens and the calf accommodation, what are we doing to reduce the environmental challenge. Again, everything. We've talked about through this webinar has been around that sort of faecal oral route of infection, so if we can keep the environments clean, we're gonna reduce the challenge that the calf sees, and so actually, Anything that we can do to reduce that contamination is gonna bring, bring a positive effect.
And that's gonna be really associated with those hygiene practises. So what are we doing around colostrum harvesting and feeding? So from the point it's being collected, so how it's collected, the equipment it's used for that, how it's stored, and then also how it's fed.
And then moving on, what are we doing around milk feeding, and that's gonna be consistency of that milk feeding, be that whole milk, how that's harvested, stored, and then fed, or if we're talking about milk replacer, it's how is that prepared? What are the steps there to make sure that we are preparing it in an accurate and correct way. And then also again the cleansing and disinfection of all the feeding equipment.
Ultimately, it's about us trying to control the controllable and prevent the exposure or at least reduce the exposure of the car to the pathogens that are out there. So I'm gonna wrap up there. Hopefully what we've gone through now is sort of, we've really illustrated the impact that this disease has on health and performance, that's a long term impact on productivity, that cost, the fact that this disease and sort of group of diseases accounts for about 50% of losses and mortalities in young calves.
We've hopefully given you a bit of a framework to investigate scar issues on farm, giving you the key areas to look at. And those will be the same no matter what the pathogen is, it's about walking through those steps and thinking about what we can do. We've really highlighted the role of Colostrum in calf health and that's starts with the immunoglobulins, but it's also all the other factors associated with it.
And we've given some idea about how we can look at failure of passive transfer and the tools that are available for us. To engage with the sort of ongoing monitoring in this area, so that we are ahead of the game when it comes to sort of looking at preventing disease outbreaks, and then. The last little bit we've sort of hopefully given some focus there about how do we really prevent neonatal scours, and it's gonna be, I was sort of as we've done, divide it into two packets, so really looking at what can we do to boost the immunity of that calf, so.
Vaccination, Colostrum, all those kind of things, and then what do we do to reduce the exposure of that calf to the pathogen that's caused gonna cause this disease, so biosecurity, hygiene, cleansing and disinfection. So I will finish there and thank you very much for your attention.