So now to move from the gestation period to the next period of the production cycle. So the sow then fallows or gives birth. She then feeds her piglets during the lactation period. Then normally piglets are abruptly weened and milk is no longer provided to the piglets. During the last two days of pregnancy, sows perform a complex nest building behavior. Under well conditions, this would involve the sow isolating herself from the herd. She would find a site, she would dig a hollow, by pawing at the ground. She would collect grasses in which to place into this hollow. Then she would collect a large number of branches. She would then go inside this nest and give birth in there. This behavior is not a learned behavior, it's an instinctive behavior. And this has been shown to be driven by the changes in hormones in late pregnancy. This complex nest building behavior has been filmed in wild boar. And we've provided a link so that you can go to this and observe the behavior. In our commercial pigs, we continue to see this complex nest building in the form of increased activity, pulling at the ground, and moving substrate around as can be seen in this clip of a sow in a farrowing pen. Given that we know commercial sows perform this complex nest building behavior, we should consider the predominate system that is used for sows when they're giving birth the farrowing crate. The farrowing crate was introduced after the second World War and is by far the predominate system used for sows during the final days of pregnancy, during lactation, and up to weaning. As you can see, the sow has her feeder and water at her head and is able to stand up and lie down but is unable to turn around. There are some production advantages compared to more spacious farrowing pens and that the space required per sow is reduced. The stock person can also treat the sow or piglets without being harmed by the sow. And that the sow is less likely to crush piglets when she lies down. However, here is Edinburgh we have done extensive research to consider the welfare consequences of keeping sows in farrowing crates compared to keeping them in a larger farrowing pen. As we already know the commercial sows continue to try to perform nest building. And this clip shows a sow in a crate attempting to nest build. When we consider the levels of a stress hormone called cortisol in the blood in sows kept in crates or pens during nest building, we can see from this graph, that cortisol levels are higher in the sows that are kept in crates rather than open pens. This along with behavioral measures suggests that the welfare of sows kept in crates during this pre-birth period is compromised. Although farrowing crates do compromise the welfare of the sow, they do provide some protection for the piglets from crushing by the sow. However genetic selection, as mentioned earlier, has focused on the number of piglets born alive. Therefore the letter size is ever-increasing, which leads to individual birth rate decreasing, and therefore these piglets are weaker at birth and are more prone to the risk of crushing by the sow. However, in the farrowing crate system of the piglet's born alive, 12% will not make it to winning. And a natural fact, in outdoor systems, and in indoor pen systems, the mortality figures are also comparable. So across all systems, more than one in ten piglets will not survive up until weaning. Perhaps refocusing and genetic selection on the number of piglets weaned rather than the number of piglets born alive would help to produce healthier, stronger, but fewer piglets at birth, which are more likely to survive through to weaning. Another reason why eliminating is beneficial to piglet welfare, is the unusual suckling style that sows have evolved. Sows don't have milk available ad lib. They do what's called a milk let down. And they only let down milk around every hour, and the milk let down itself only lasts for around 20 to 30 seconds. It's really important that all piglets are at the udder and ready for this milk letdown. Sous normally have around 14 teats and therefore this is the maximum number that the sow can actually suckle. So in the next video clip, you'll see this milk letdown. What you'll see is the sow grunting. This communicates to the piglets that milk let down is about to happen. The piglets will assemble at the udder. They'll all suckle on their own teat. And you'll see them nosing the teats, and then eventually the grunting will become more frequent and then eventually you'll see rapid suckling of the piglets' nose. And this is when milk letdown occurs. It only lasts for around, as I said, 20 to 30 seconds. You'll then see the piglets starting to move around. And milk is no longer being let down at this point. Because of this unusual style of suckling, it's really important that every piglet is present for the milk letdown. Interestingly piglets develop what's known as a teat order, in around the first 24 hours of life. This is where they attach to a teat and they repeatedly suckle from that same teat throughout lactation. This development of the teat order, helps to minimize aggression between piglets, so they're not fighting with each other at every suckling. And also minimizes the chance that any piglet will miss a milk let-down. If a piglet in that early period fails to establish a teat, then it can be in some trouble and will potentially miss milk let-downs. And this is where management can step in and common techniques used in this situation would be to cross-foster the piglet or perhaps to remove the piglet and to use artificial milk. During the lactation period, we also have to consider other piglet welfare issues other than piglet mortality. I'm going to talk about mutilations. These are procedures that interfere with sensitive tissues or bone structure for purposes other than medical treatment. These mutilations normally happen in the few days of life and they're generally done without any anaesthetical pain relief. The first mutilation that I want to talk about is teeth clipping. Piglets are born with very sharp eye or needle teeth. Again, if there's an excessive number of piglets in the litter, it can be difficult for them to develop their teat order. If this is happening and there's a lot of aggression and fighting going on within the litter, then the teeth can cause damage to the piglet's faces and also to the udder of the sow. So to prevent this, piglets are generally routinely teeth clipped within the first few days. Another thing to consider is the identification of the piglets. This could be done in a number of ways, including tattooing. But these pictures here on the screen show a picture of an ear tag which has been pierced through the ear of the piglet. And also ear notching, whereby a pattern of notches are removed from the outer part of the ear in a pattern. As male pigs grow and reach sexual maturity, the pheromones that they produce can cause a distinctive taste of the meat called boar taint. To prevent this, male piglets are routinely castrated in the first few days of life by cutting the scrotal sac and removing the testes by peeling. So once these piglets are weaned and enter into the growing phase, if they're kept in suboptimal environments or, particularly, barren environments, they can find each other's tails very interesting and they're very easy to manipulate in their mouth. This can lead to what's known as tail biting. And this can cause the tail to become damaged, become painful for the recipient pig and also can cause some damage in terms of the meat quality. So to prevent this, tail docking is often done within the first few days of life to remove a large proportion of the tail. Within the EU, there is no legislation which prevents the routine tail docking of piglets, however it is still a common practice globally. There are a considerable number of mutilations that happen to these piglets in the first few days of life. We need to think about the consequences for their welfare, including the pain associated with these types of mutilations. We need to consider ways of minimizing the need for these mutilations through thinking about genetic selection the environment, and management. There have already been some efforts on this. For example, there's been somewhat looking at how we can adapt the environment to minimize the incidence of tail biting and also looking at non painful methods of castration. The final issue I'd like to talk about is weaning. In the wild, piglets, during the lactation period, would normally spend more and more time away from the sow. They would be learning about new types of food and weaning would finally happen around 12 to 17 weeks of age. In commercial practice, piglets are normally weaned abruptly, at around three to four weeks of age. The legal minimum in the EU is three weeks old, but in other parts of the world, there's no legislation relating to weaning age. The reason, of course, that piglets are weaned this early is so that the sow can be mated again and produce more litters per year. When abruptly weaned in this way, there are impacts for both the sow and piglets. For the sow, there's separation from her litter, the change of environment back to the pregnancy accommodation and the return to the restricted diet. For the piglet, there's separation from the sow, often mixing with other litters, a change of diet and a new environment. Again, some consideration of the impact of early abrupt weaning needs to be considered and ways in which this can be minimized. Although this presentation may seem a little negative, there is a large amount of research going on here in Edinburgh, and around the world by animal welfare scientists who are trying to address some of these pig welfare issues. For example, here in Edinburgh, we are developing a free farrowing system. We've provided you with a link so that you can find out some more information about that. I hope that this presentation has given you some information about pig welfare issues. If you have any questions or comments, then please free to post on the discuss board, we'll be happy to discuss them with you. Thanks for listening.
