In this chapter of the report there will be a few share questions answered all related with feed. First the digestion of the pig is explained, after that the diet of a pig in different stages of production is elaborated, and as last there is told what and how much a pig produces, and what the relation with quality of feed/feed ingredients it has.
2.1 How does digestion work for a pig?
The digestion system from a pig is about the same as the digestion system from us humans. In the first chapter of this report the digestion system will be explained by short explanation for each part of the digestive system of the pig. In figure 1 the digestive system of a pig is shown with all the different parts named.
Mouth
The entire digestive process begins in the mouth cavity. The teeth in the mouth reduce the size of the feed parts. The tongue of the pig mixes the food with saliva. The saliva contains an enzyme that can split starch and thus has an important function. The saliva will also ensures that swallowing the feed will go easier.
Esophagus
Through the esophagus the food is transported to the stomach with the help of the Peristaltic movement. This act should happen very smoothly, this may be due to the mucus that is produced in the esophageal wall.
Stomach
Once arrived at the stomach, food is further digested. The stomach has multiple functions. Such as food storage, mixing different acids and enzymes with the food. Enzymes need to start the digestion of protein and fat in the stomach. And the last function of the stomach is to guide the feed to the small intestine.
The stomach wall contains cells that produce mucus and bicarbonate. This ensures protection of the stomach wall against the acid which is used within the digestion. The stomach has a low pH in many places because of the acid, this encourages the killing of bacteria.
Duodenum
The duodenum is the part that comes after the stomach. The feed can only enter the duodenum when it is neutralized. This means that the pH value should be neutral first. Neutralizing the pH happens in the stomach. The lower the pH of the stomach content, the longer it takes for the feed to be transported to the duodenum.
Pancreas
The pancreas helps with the neutralization of the pH. It also helps with the production of enzymes for the digestion of proteins, fats and starches. The pancreas produces many juices and separates these within the duodenum. These juices contain sodium carbonate and digestive enzymes like trypsin and chymotrypsin. These are needed for the digestion of protein. Also the enzyme Lipase is present, this enzyme is necessary for the digestion of fat. Then there is amylase which is useful for the digestion of starch.
Gallbladder
Bile is produced in the liver, and stored in the gallbladder. Bile allows for the digestion of fats. It serves as an emulsifier, which Lipase can digest the fats completely.
Small intestine
The small intestine provides the degradation of feed, including water and nutrients. The small intestine is the immune barrier between the feed and the body. The small intestine consists of 3 parts, the duodenum, the jejunum and the ileum. The duodenum is already explained earlier under the heading “duodenum”. After the duodenum there is the jejunum. In the jejunum the acidity is increased so that the pH value is optimal for the digestive enzymes. The absorption surface of the intestine is enhanced by folds in the intestinal wall.
Large Intestine
After the small intestine the leftover feed is transported to the large intestine. Here are intestinal contents, mucus and bacteria mixed by the Peristaltic movement. The main function of the large intestine is the absorption of water.
The large intestine consists of four main sections. First, mass from the small intestine passes into the caecum. The caecum has two sections, the first section has a blind end, material can’t pass this. The caecum has a second section where it connects to the colon, in this part the mass is passed to the rectum and anus where the remaining mass is excreted.
(VARKENSOPDRACHT, 2017) (dvw, 2011) (site, 2009)
2.2 What is the diet of a pig in different stages of production?
A pig is not picky. It eats just about anything. But from begin to the end of the process the pig has not the same diet. A pig needs different feed in the different stages of production to have the best growth.
The production of meat consists of 3 stages. The first stage is when the piglets are born. This stage takes about three weeks. In the first 3 weeks the piglets drink milk from the sow. The piglets drink approximately 1 liter milk per day. This milk contains a lot of lactose and fats. In the begin of this it is very important that the piglets get enough colostrum. Colostrum contains antibodies which the piglets need in order to grow properly. (Hendrix, 2014) (Varkess, 2012)
When they are a little bit older they get a small amount of milk powder next to the milk from the sow. This is to be ensured that they will get enough nutrition, but mainly to slowly let them get used to eat solid feed. In the last week before they get weaned, and if the piglets are big enough, it is possible to feed them a little bit of grain so the transition to the nursery where they will only get grain is easier. (Varkess, 2012)
The more feed young piglets get during farrowing and in the first few days after weaning, the better they perform in the rearing and fattening phase. A well-stocked healthy piglet on four days after weaning is able to achieve top results. (Heus, 2017)
The second stage is the nursery, this stage takes about eight till ten weeks. During this eight till ten weeks the piglets are fed grains in combination with water. In this stage the piglets will grow until they are about 25 kg. This transition from farrowing to nursery is not really easy for the piglets. Their diet will change from fluid to solid feed. These grains consists a lot of starch and sugars. (Varkess, 2012)
The last stage in pig production is the fattening stage. In this stage the aim for companies is a rapid growth, low feed consumption and a good slaughter quality. On average these fattening pigs daily have a diet containing 3,300 kcal of ME/kg. The diet of the pigs in this stage is a grain consisting of mostly soy and corn. This makes the feed a protein rich source, which is necessary for the production of muscles on the pig. The feed does not only need to be protein rich but also consisting of other ingredients so you have the correct feed composition with which the pigs can grow rapidly in a healthy way. (Cromwell, 2016)
2.3 What and how much does a pig produce?
The main product that a pig produce is meat. The pigs are about 110 kg when they are slaughtered. Of these 110 kg around 70 kg suitable to eat. On average this is 60% of the pig. Around 28% of a pig’s live weight is inedible product. The remainder consists of bones (18 kg), intestines with content (8 kg), organs, blood (4.5 kg) and hair (1 kg). (ODA, -) (Vlees, 2016) (Voedingscentrum, 2017)
2.4 What is the relation with quality of feed/feed ingredients?
In order to achieve optimal growth, it is important that animals can digest their feed. The animals need a well-developed stomach intestine system to be able to digest the feed. What also influences the passage speed and therefore affects the digestion is the feed composition and the raw material choice. (dvw, 2011)
In various ways there is responded with the feed to get an optimal digestion of the feed. A quick drop of the pH in the stomach (this is especially important with young piglets) is stimulated by adding acids to the feed, and by ensuring there are little buffers present in the feed. These buffers slow down the drop of the pH. Processing raw materials provide a syrupy stomach contents, which drops the flow rate from the stomach to the small intestine. In this way the enzymes in the stomach have more time to work on the feed.
At last the grinding fineness is also of interest. The smaller the feed particles the better and quicker the enzymes can do their work. In being so, the influence of finely ground feed and the risk of stomach ulcers have to be kept in mind. (dvw, 2011)
3. Diseases
In chapter 3 of the report share topics related to diseases are elaborated. First there will be given what diseases there are related to feed. And after that there will be explained what can be done through farm management to prevent these kind of diseases.
3.1 What are feed related diseases for a pig in China?
There are several diseases which occur on pigs that has to do with nutrition. The first one is Colitis. Colitis means inflammation of the large intestine, this disease is very common in many countries. It is recognized by sloppy faeces which looks like it is from a cow. Furthermore the pigs appear normal. There is no blood in it and only a little mucus present but it is possible that the condition progresses to severe diarrhea. If the disease As the disease and its severity progress, a very watery diarrhea, with dehydration, loss of condition and poor growth become evident in the pigs. The pigs that are affected are usually 6 to 12 weeks of age and in a certain group. Up to 50% of the population can be affected. This disease does not occur in adult or young piglets.
However dietary factors also precipitate disease and pelleted feed is much more likely to be associated with the disease than meal. If the incriminating pellets are ground back to meal, demonstrating an effect or ulcerative still results the pelleting process. Certain components in the feed are also implicated including poor quality carbohydrates, oils and specific ones have not been identified but may include anti trypsin factors and oligosaccharides
.
3.2 What can you do through farm-management to prevent these feed related diseases?
4. Protein sources
Soybean meal is a widely available feed for farm animals, rich in protein. It has a high biological value and digestibility, and considerable energy content. The main importer in the world is China. By the increasing prosperity in the last 15 years the amount of soy that is imported is increased sevenfold. In 2011 China imported 54 million tonnes of soy and produced on itself on average 15 million tonnes. (Katrijn Ingels, 2013)
Unfortunately, in recent years, soybean meal has become so expensive that other vegetable feedstuffs are urgently sought after by nutritionists and feed industries. In this chapter there will be looked at alternative protein sources for the feed for pigs.
4.1 What alternative protein sources are available for a pig in China?
Rapeseed
Rapeseed (Brassica napus) belongs to the family of cruciferous. Rapeseed contains 42% of oil. After
oil production there remain interesting rest products. This residual products can be used as a protein source in replacement of soy meal. (Katrijn Ingels, 2013)
In 2012 China was the second biggest producer of rapeseed. (Wikipedia, 2017)
For the pig nutrition are only rapeseed varieties with a low glucosinolate content usable. The feed
should not contain more than 3 mmol Glucosinolates per kg, otherwise this will have a negative effects on the feed intake and growth. (Katrijn Ingels, 2013)
Sunflower seed
For pigs, there should be used sunflower seed scrap with a low fiber content and a higher
protein content. Sunflower seed scrap with a low fiber content can replaced 25-50% of the soy meal in pig nutrition without negatively impact on growth performance and carcass quality. When more than 50% soya meal is replaced by sunflower pit scrap, it is necessary to supplement with pure amino acids or raw materials that are rich in lysine. This is especially important in the beginning of the fattening phase. At higher interference percentages to the total fat content of the ration need to be kept an eye on. High fat content can provide a reduced meat quality. (Hollis, 2002) (Katrijn Ingels, 2013)
China does produce sunflower seeds. They were the 5th biggest producer of sunflower seeds of the whole world with 6,3% of the worldwide production. (Seed, 2015)
In table 1 some values are shown from sunflower and rapeseed in comparison with soybean.
Source: (Florou-Paneri, 2014)
Flaxseed
The use of flaxseed in feed for pigs should be limited for young animals because of the presence of ANF (Anti-nutritional factors). In the start ration of young piglets, the amount should be limited up to a maximum of 5%. If larger amounts are used the animals shows reduced performance. For fattening pigs this amount is up to 10%. Flaxseed included in the feed results without adverse effects on performance. But at higher percentages the slaughter quality can be affected and it can provide soft and yellow bacon. In addition a to high use can lead to abnormal taste or smell of the meat by the breakdown of the fatty acids. (Florou-Paneri, 2014) (Katrijn Ingels, 2013)
Peas
The use of peas for fattening pigs is possible as alternative protein source. There are no significant adverse effects from the use of peas on the performance of finishing pigs. Most studies recommend a maximum intervention percentage of 15-20% to 20-30% in the start feed from fattening pigs. There can be used higher levels of peas in the feed for fattening pigs when they are a bit older because the feed digestibility of peas rises as the animals age. (Florou-Paneri, 2014) (Katrijn Ingels, 2013)
Algae
In addition, algae with high-quality protein are considered a non-conventional source of protein in pig feed, similar to soya meal. The algae has a lot of advantages over other plants such as higher productivity, ability to be grown in different climatic conditions and regions, no need of good arable land for cultivation, power to hold excess atmospheric CO2 and to produce O2 thus helping in the reduction of the greenhouse effect. (Florou-Paneri, 2014)
Insects
4.2 How will/can alternative protein sources impact production and sustainability for China?
Insects can be a sustainable alternative protein rich raw material, in particular when the insects are grown on substrates of organic waste and secondary flows. Insects are cold blooded and can result in low quality biomass efficiently upgrade to high quality protein. For this study is based on the assumption that an insect chain could consist of different links as shown in the following process diagram
The sources that are named earlier in share question 4.1 seem to be promising materials for pig nutrition, as well as the protection of the environment through the production of carbon footprint reduction. (Florou-Paneri, 2014)
5. Breeding
In this chapter of the report the breeding system of a pig is explained. After that there is looked at how breeding can help to improve the production level of a pig, and how it can help health risks within feed related diseases.
5.1 Breeding-system of pig
Insemination
A female pig is called a sow and is able to breed starting from an age of seven months. A female pig that not has given birth to piglets yet is called a gilt. A sow is on heat every three weeks. To look which sows or gilts are on heat and can be inseminated, a boar is walking in front of the sows and gilts. When a sow or gilt is ready to be inseminated it’s showing on heat behavior when the boar is passing by. An example of on heat behavior is when the sow or gilt is putting up her ears straight up. A boar is able to start breeding from an age of eight months. The cycle time of a sow being on heat is on average 21 days. In this time there should be insemination taking place.
Gestation
The gestation period of a sow is about 115 days. So this is three months, three weeks and three days. A sow can give birth up to twenty piglets, but the average is thirteen. Piglets are weaned when they are between twenty-one and twenty eight days old. When the piglets are weaned this means that the piglets are taken away from their mother. After weaning the piglets are called weaned piglets. Gestation can be controlled by making an ultrasound. This is possible after about 23 days after insemination. During gestation there are hardly any to no behavioral changes visible on the sow.
Development of the piglets
If once a sow is pregnant there must be looked a little deeper in the body to see the processes that take place. What stands out is that the uterus is very small. This is because the piglets are not in there, but in the uterine horns. This makes the surface a lot bigger. This is also needed since they give birth to about thirteen piglets or even more.
In figure 2 the entire schedule of the development is shown. However, this is only till day 32. The embryo grows of course further and gets all the organs in the end. But it makes For everything is a little clearer on schematic.
It all starts with fertilization. Here are the egg and sperm cell merged together. This part happens in the fallopian tube. Once the egg is fertilized it will keep dividing itself. This clump of cells is then called the blastula. The blastula moves towards the uterus horn during dividing. The clump of cells is getting bigger and split itself in half. The outer layer grows to the placenta and the amniotic membranes. The embryo develops in the inner layer.
Once arrived in the uterus horn, it implants. The cells merge with the mucous membrane and the inner part of the 2 layers divide itself again. The outer layer develops into the skin, nerves and senses. The inner layer develops further to the digestive organs and the respiratory organs. Later there will be a third layer formed, which is called the mesoderm. Here are blood, muscles and bones formed. Eventually the embryo is big and strong enough, so the sow can give birth.
Birth
In the most cases a sow can manage giving birth herself. When this is not the case, for example when it’s taking too long, the sow gets an injection with hormones (oxytocin) which stimulates the process or/and is being palpated. Oxytocin is a hormone that the body produces for the contractions to take place.
5.2 How can breeding help to improve production level of a pig?
5.3 How can breeding help to lower health risks within feed and feed related diseases?
11.What are developments in China for pigs/pigs sector looking in two directions; high tech agriculture and organic agriculture? What are sustainable solutions to actual problems?
https://www.your-bizbook.com/en/Club-China-News/chinas-big-leap-in-pig-farming–more-professional–efficient
Conclusion
Consequently, a wide range of protein sources of plant origin have been explored in the effort to find sustainable alternative sources of protein to replace SBM. Nevertheless, these alternative protein supplements must fulfil certain criteria, such as the maintenance of pig health, welfare and performance, the possibility of reduction of the environmental footprint and adequate cost-effectiveness.