[SOUND] Welcome, this is the lactation biology course. My name is Walt Hurley, I am a Professor in the Department of Animal Sciences at the University of Illinois in Urbana-Champagne, Illinois. This course is going to be a survey course about this topic called lactation biology. Our goal is to try to give you some background, kind of hitting on the surface of a lot of different kinds of areas that relate to lactate biology. So that hopefully, you can go out and look more deeply or understand more deeply topics that might be of particular interest to you. So, I want to kind of share with you for a moment the way we've organized this course and different kinds of modules. Let's go to the first slide here. Again, lactation biology, a very, very broad topic and we've kind of broken this down and helped you kind of organize it into different areas. Introduction, we'll kind of introduce some of the background and perspectives of lactation biology. So we can kind of start thinking, how do we think about this field of lactation? Mammary structure, mammary gland structure. Milk composition, milk synthesis. So, what is milk and what is the composition? And a little bit on how it's synthesized. Mammary gland development. How's the mammary gland develop at different stages of development of this tissue called the mammary gland. Mother and neonate. This is one where I've kind of put together some things where at birth of the young, we have the mother, we have the mammary gland and we also have the neonate. So we start putting those things together and they start impacting each other, and we'll talk a little bit about that here. Lactation. Obviously, the namesake of the course, but this is really only one component of lactation biology. Mastitis, major disease in animals, particularly in dairy cattle, but also in all other animals who lactate. So usually caused by a bacteria, but it's technically called an inflammation of the mammary gland and then comparative lactation where we're going to examine a little bit more detail and certain other kinds of species. Dairy cattle will be one of our key species, but we'll also talk about pigs. We'll talk about goats. We'll talk about a variety of kinds of species and all of these, but especially in that in the comparative lactation module. So, that's kind of give you an over view of what we're going to do in this course. But to get started, what I'd like to do is to, again, start offering some perspectives on this topic. To start out, let's consider kind of what we think we might know about this topic of lactation. So I've been teaching a course for a very long time on the University of Illinois campus, lactation biology, undergraduates. Very few of them are from a farm, very few of them have had any experience to do with this topic at all. You might have had a little bit of background information, but very, very little. And typically, I go through this series of questions, who, what, so on and so forth and I want to do that with you. And I think you probably will come up similar kinds of things, similar kinds of responses to these questions that my students would here on campus. So, who lactates? Let's go to the next slide. Female mammal, this is very typical response. And so, two things to recognize is this preference for female. That is to say that most people would say, yeah, females are the ones that lactate. That's fine and that it's a peculiarity or characteristic of mammals. So, other non-mammal animals do not lactate. So, we're talking about a group of animals called mammals and there's over 5,000 species of mammals. What it lactates? So, that is what is the structure that lactates? We go to the next slide, mammary gland. So in humans, a lot of times, we call this the breast. In cows, we call it an udder, but mammary gland is a word that works for all species of mammals. So that's the structure that actually is producing the product, which is the next question. What is produced? Milk. Most people would say, yeah, milk is produced and we'll come back to that here in a moment and try to expand. We're actually going to expand over a lot of these topics. Where does lactation happen? Ventral surface. So what you'll find is that the mammary gland, the breast and so on is always on the ventral surface of the animal. So, you don't find it up here in the head. You don't find them on the back. You don't find them on the legs. They're a long line on either side of the midline on the ventral surface of the animals. And again, a lot of variation on where they are in terms of different species. When does lactation start? And again, most people will recognize that there's a relationship between this process of lactation, the physiological process of lactation and birth of the young, birth of the offspring that there's some kind of relationship there. Why does lactation happen? And again, most people would say, well, it has to do the neonate. So we're somehow providing nutrients, etc., etc., for the neonate and that's certainly true. How does lactation happen? Well, that's what you have to do. That's what this course is about. We're going to explore various components of the why part. Before we leave this and again, these are fairly standard responses. I think most people would come up with similar responses to this. Let's go back, an example just a little bit further. So, a couple of assumptions here. Mammals. Who lactates? Mammals, yes. Other species do not lactate, but female, do males lactate? The answer is yeah and we'll talk about that some later on, and kind of think about how that might happen. What lactates? Mammary gland. Yes, that's the tissue. It's a skin gland. It's outside the body. It is the tissue that's going to produce milk. What is produced? Milk. Is that the only secretion that's produced by the mammary gland? The answer is no. Colostrum would be probably the easiest example to think about. The first milk out of the, first mammary secretion out of the mammary gland when the young are born. So actually, mammary secretion might be an even better way of a broader term for this, even after the animal has done lactating and the mammary gland regresses. In some species, there's still some secretion that can be obtained from that gland. So, milk is a term that we will define more carefully and look at more carefully as we go into other modules. Where does lactation occur? In the ventral surface. But again, a lot of difference in our species here in the thoracic region. Cows are in the inguinal region, pigs and other litter bearing species will have them all the way up down the line. So, a lot of variation there. Let's get down to this one, when does lactation start? At the birth of the offspring. Again, this idea that there's a close relationship between the process of giving birth and the process of causing that mammary gland to undergo, the term is like to genesis. Initiation of lactation which results in synthesis and secretion of milk, but it can happen at other times as well and under other circumstances. So this one again is the major ways it occurs, the relationship between both the offspring and starting of lactation, but the process can also occur under other conditions as well and we'll explore some of those in other modules as well. And again, to provide for the neonate. And again, this idea is not just providing nutrients, providing protective factors, antimicrobial factors, growth factors, hormones, etc., etc., that are always produced as part of this thing that we call milk. And again, we'll explore some of those, especially in the milk composition module. And again, so what is a process? Examining these things. Expanding upon these ideas. We'll expand upon those as we go through the course in other modules. [SOUND]
