[MUSIC] So one of the most important ways of preventing or minimizing infectious disease is maximizing the immune defense in our hosts. And we have a whole range of management practices, which impact the immune status of those animals. When an animal's immune system responds abnormally to a managemental situation, we call it stress. That's a very broad term, really. The calving period is a time in which we need to manage the stress very, very carefully. It is a natural process and there's a natural stress. There is a normal magnitude in which the difficulty in giving birth helps the calf's adaptation to the new environment. It helps the establishment of a good immune system for the calf. It has them take their first breath. It helps the circulation get established. It helps them adapt to this brand new environment they're in. So monitoring calving, watching calving, observing, making sure that you understand the different signs at different stages of the carving process is very, very important. And not letting any one stage go too long, and intervening in the right stage is an important bit in managing stress. So what we want to do is follow some cows through the calving process to give you some idea about what the signs are of normal calving. So that as you are looking at animals, or you are involved in those kinds of processes perhaps. You might be able to look at the host and know what's going on inside. Let's see if we can get inside the head of this cow and see what she's thinking. This cow is within one to two hours of calving. So what's happening inside of her are the first stages of the preparation for the calf coming out of the vaginal tract. So the mechanical processes are instituted by a number of endocrinological changes, there's hormone changes that are making sure that the uterus is sensitized and ready to move the calf out. One of the first signs of stage one parturition is abdominal pain. So myometrial contractions are taking place. The uterus, the muscle of the uterus is contracting. And so for the cow that's probably quite an unusual feeling. In humans we talk about that as the contractions and that's when things are moving along, that's the time to go to the hospital. But for this cow, she's uncomfortable. She's walking around, she's, making, taking abnormal postures with her back leg spread. She's switching her tail, she's looking at her abdomen. She's salivating, she might think she wants to urinate or defecate. You can see also that the hormone changes, the endocrinological changes are getting the milk production ready. So her udder is quite tense and taut. That's because it's full of milk. And here she is. She might feel I need to urinate, or I need to defecate. But what's happening is the fetus is going, and that is the first sign of fetal fluid. So that wasn't urine that was quite a thick fluid that came out, and that is actually the first fetal fluids. So that means as the muscles of the uterus are contracting, the calf is now coming up into the pelvis, and the fecal water, the first membranes are going to be broken and we are going to see some fecal membranes. Now you can see the stickiness on the back of that udder. Urine normally comes out in a thin stream but that was quite mucusy and sticky, and it's sticking to the back of her udder. So, again, she walks past the water trough. She's looking as though she's holding her legs apart. She's slightly anxious, not know what's going on. She's not eating, not drinking, she'll go up to the water trough several times, but not take a drink. She might go to the hay bale, and here there's ample food, and ample water available at all time. An excellent management system. So, she's in stage one, she's not abdominally pressing at all, she's not forcing anything out. The calf is not yet in the pelvic canal, but the uterus is contracting and that is what is making her uncomfortable and walking around. You can see how the tail is raised. She knows that something is going on. She is flicking her tail and instead of the tail being sitting back and resting, against the perennium, the anus, and the vagina, it's held up high. And that's purposeful, because that's going to minimize some of the contamination that the calf is going to experience as it comes out. You see when they calf, they lift their tail up. If that was covered in feces that might be exposing the calf to too many microbes. So actually, the natural process of lifting the tail up makes sure that the calf doesn't get exposed to too many microbes. Again, you can see her compared to the other cows in the neighboring pen. Some of them have had calves already and they are resting. They're chewing their cud. They are moving around, licking their legs, doing normal processes showing that they are not exhibiting any abdominal pains. So the contrast between cows that have had calves or cows that are a long way off calving, and this cow in which calving is imminent within the next 60 to 120 minutes, if all goes normally. Is something to be noted and that's how you would, in a group pick out a cow that needs close observation. [MUSIC]
