[SOUND] [MUSIC] So Brian Aldridge from the University of Illinois, College of Veterinary Medicine. We've been talking about how the microbial populations in the body were established. So we talked a lot about that perinatal period, that period around calving, or around birth. And we've understood that the in utero environment, the environment in the uterus is essentially sterile, so the new born animal would have no microbes on its skin, in its respiratory tract, in its mouth, or its intestine if it didn't acquire it from it's environment. We looked at how the birth process was important in that. In how as the calf emerged, it picked up microbial populations from the mother's reproductive tract, from the birth canal and from the vagina. And then in the calving area, we saw how the calf and the cow would lick the calf. And how the calf was spent quite a lot of time on the ground. And how it would acquire some of the microbes from the immediate environment into which it was born. We then thought about how the calf would get its microbial populations from its first milk from its colostrum. And managementally how we handle that colostrum is really important in making sure that the correct microbes in quantity and quality are required by the newborn animal. Now this animal has been born, has received its colostrum has been in that both environment for a few hours. And now, it's been transported to this large unit where it will spend the next eight weeks of its life. Now in this unit, there's probably 5,000 to 8,000 calves around us, but this calf is isolated from the other animals even in this row, which contains several hundred calf pens by this unit in which it will live. And this outside unit, and this outside fence, which really stops it from having direct contact with other calves. So you can imagine a calf in isolation like this will have a different microbial population that's one that put directly into a large group of calves. But this is a good welfare environment because if the calf comes out, it can see many other calves. As you can hear, it can hear many other calves. So it doesn't have the stress of separation and isolation, even though there is some physical isolation, which will in some way help us manage its microbial environment. So this calf just came on a trailer, so the trailer itself would be a source of some microbes. As you can it was handled well, handled carefully, handled gently, and placed in here. But this now becomes its new ecosystem, this becomes where it acquires new microbes, you can see here, the bedding used here is sand. It's fresh sand, hasn't been used for anything else. Now the previous calves that were in here have no direct or indirect contact with this calf, because none of the manure from the previous calves is left here, none of the saliva that the previous calves had is left here. These units have been cleaned, they've been hoofed, they've been sterilized, so none of those previous microbes are minimal amount of microbes will reach this calf. That's true of pathogens and ones that will give them disease. And why is that important? This calf is exquisitely sensitive to pathogens, to the bad microbes, the disease causing microbes. So this kind of system allows us to control the microbes that can become established in this calf's body. But the calf now as it adapts to this environment, at the moment you can see the calf is just been transported and is will be waiting to rest, hasn't been fed yet. But this direct environment, and the feed that it receives through milk, through grain and concentrate, through water, will control what microbes become established in its body. So we've looked at ideal calving environments where the calf is exposed to an environment of the right temperature, the right humidity, and also of the right hygiene and so it's dry and there's not excessive exposure to feces. If we just show you a calf just for a moment, where that might not be an ideal situation and where a calf is likely to develop a different microbiome because they've been calve into a different environment. So if you look at this calf here, this calf is covered in still the wet fluids, and knows the carving fluids. But also there's a lot of manure of cow feces on this calf as well. You can see the calf is shivering. And is using some of it's nutrients and some of it's energy resources to maintain it's body temperature as well by the shivering process. Now shivering is good, so that's good to see the calf that's having a thermoregulatory response. But the microbiome of this calf will be very, very different than a calf that's born into a dry, and environment with low fecal exposure. As we think about the microbial ecology on any of our farm premises and our production systems, those microbes are really important as we know in establishing the normal commensal populations of the different organs systems in the animal, the microbiome. But also in the circulation of pathogens around a premises or between animals on a premises. Now when we think about that microbiome and the pathogens, we have to think about the ecosystem of the microbes in that farm, and one important aspect of that is that actually the feces of the animals that are already in place. The feces become a huge source of microbes to all of the other animals. So really, animals on a premises are exchanging microbes by being exposed to each other's feces. So how do you control that? Manegementally, it's a very, very important part of an efficient and sustainable production system. And you could think of any means, any different ways of dealing with that manure load. We want a normal, clean, hygienic environment, not no manure exposure. Because that microbiome is also stimulating the immune system. We want a low level of exposure, but we don't want the immune system to be overwhelmed. And we don't want too many pathogens. And we don't want an unbalanced microbiome. So taking care of the manure is very, very important from a microbiological standpoint. So you can think about a situation with a small herd or a small flock but you might just be using a bucket and a shovel and you're just collecting those feces and removing them from the animal environment at a regular interval. But in a farm like these where there are thousands and thousands of cows, how do you cope with the hundreds of thousands of gallons of manure produced each day. This is one way in which this enterprise copes with that and that's by using which is in essence a vacuum cleaner. This is one of many that go around the farm and clear the manure from the cow passages three times a day. And you'll see from looking at the housing that the manure exposure is tightly controlled because of this vacuuming up. It's removed, it's put into this tank and it's taken to a manure processing facility. So, the cows, you'll see, the results of that are very, very clean. They're not exposed to excessive amounts of manure and the microbes in that manure. Again, probably giving them a very balanced microbiome, and reducing their exposure to potential pathogens. But for your system, you have to find the right system to control the microbe exposure so that the microbiome is healthy and the pathogen exposure is minimal. [MUSIC]