Social and structural environment

Floor Spacing

Floor spacing for swine production will be for essential sustainability:

• The total of pigs kept per floor spacing unit has an important influence on the cost of housing.  It is the tendency to keep more pigs on a smaller floor space, but this is bringing more problems regarding environmental control, disease and hygiene, dung and waste removal as well as the adaptability of the pigs. 
• You are also by now aware of how the production performance is influenced by the above factors.
• A high-density use of floor space requires a very well planned building and facilities inside.  It also requires a very highly skilled manager.
• From an economical point of view, it is better to utilize the floor space to its maximum whilst achieving the highest production levels.

 

Floor space specifications for pigs in different stages of production:

Weaned sows

• 1.8m² / sow

Pregnant sows

• In groups

• Sleeping space                 –           1.3 – 1.8m² / sow
• During removal space      –           1.3 – 1.8m² / sow
• Individual feeding space –           1.3m² / sow
• TOTAL                                      3.9 – 4.9m² / sow

• Individual sow in a crate –           0.75m² / sow

Sow with piglets

• Weaner pen with crate, only used for 3 weeks: 3.5m² / sow / litter
• Weaner pen with crate, piglets weaned after 6-weeks: 5-4-65m² / sow / litter
• Conventional weaner pen also being used as a weaner pen after 3(a): 7.9 – 10.7m² / sow / litter

Weaner pigs

• Age 2 – 8 weeks:                          0.21 – 0.27m² / piglet
• Age 8 – 12 weeks:                        0.33m² / piglet

Growing pigs

• 20 – 50kg live mass:          0.35 – 0.46m² / pig     

Finisher pigs

• Floor space will vary according to the types of system: 0.60 – 0.82m² / pig. Increase for bigger (heavier) pigs (90 – 100kg’s) up to 1.0m² / pig, or in case of extremely high temperatures.

Boars

• Including mating deck:                  9.3m² / boar

 

Lightning conditions

According to all research, the length or lack of lightning and or darkness has no influence on the growth or production of pigs.  Some darkness in fact do help to prevent fighting, cannibalism and stress.  Always remember the importance of Vitamin D that is mostly produced by sunlight.

The importance of windows must also be considered, for example for heating in winter and for sufficient airflow in summer.  Windows must be placed as high as possible to the roof of the building.  Sunlight is further important to dry the floors and waste.

 

Various type of pig housing

The most modern direction of piggeries is to build in complete closed structure.

The biggest advantage is that one can control the inside environment completely in an artificial way, for example, electrical heaters, fans, lights, etc.  This type of housing is very expensive.

 

Half closed house:

This is when the walls are not builds completely up to the roof, and the walls facing the wind direction are higher than the opposite wall.  It is practical to build the openings up to the size that a bale of Lucerne can exactly fit in.  The advantage is that in winter, the temperature or cold winds can be controlled this way.  This type of housing is cheaper.  It is still important to isolate the weaner pens.

 

Dung, urine and waste water drainage

Removal and management of dung, urine and waste:

It is very important to plan a pig house in such a way that the waste can be removed as early and cheaply as possible.  The floor must be sloped so that the water can be drained easily.  Try to plan in such a way that the waste can be used in a vegetable garden.  It is important to clean, wash and disinfect the house at least 3 times a week.

Recommended spacing of wooden floors

Pigs	Strip size 3 – 5mm)	Strip size (10 – 12mm)
Newborn piglet	10mm	10 – 25mm
10 – 20kg piglet	12.5mm	20 – 25mm
20 – 100kg pig	Not recommended	25mm
Sow	Not recommended	33mm

 

Note:

It is better to use bigger spacing for newborn pigs (25mm) so that they can’t get stuck between the spacing.  They quickly learn to step on to the strips.

Different types of waste removal systems

 

General revision

In summary:

Good housing is the basic of efficient pig farming therefore it should be effective and planned in such a way that is beneficial for health of the animal.  Good facilities can save labour costs and time.

Housing can be made of curved corrugated sheets with one end boarded in, thus forming a draught free warm snug pocket.  A fairly generous amount of straw is used for bedding and at farrowing a retaining board keeps the litter inside the shelter for a few days.

A farrowing crate of frame is now incorporated which gives protection at birth.

Heat and light can be provided by portable gas system.

Optimal results can only be expected if the housing scheme provides for.

• Shelter against cold, rain, heat, sun and wind.
• Hygiene and disease control.
• Efficient handling and management of pigs.
• Minimizing costs.
• Ease and rest for pigs.
• Optimal conditions for the different physiological stadia in the pig’s life.

 

The newborn piglet

The piglets are extremely cold susceptible.  As it grows older, it shows this characteristic to a progressively decreasing degree until by the time it is mature, it exhibits heat susceptibility. 

The reason for this cold susceptibility is the following:

• Hardly any hair or fat.
• Thin skin.
• Low heat production.

 

The growing pig

The animal is bigger, with a smaller metabolic rate per unit body mass.  It has a thicker layer of fat to protect it against cold. Growing pigs are susceptible to excessive heat.  Pigs raised in a hot room develop longer legs, tails and a greater blood supply to the skin.  High temperatures adversely affect reproduction.  At 33ºC feed consumption increases.  Respiratory rate also increases.

 

Porker and baconers

Porkers and baconers, the main difference between the two is the slaughter weight:

• Porkers: 45kg Live mass about 22ºC
• Baconers: 90 – 95kg live mass about 18ºC

At temperatures higher than 37ºC the heavier pigs lose mass.  At temperatures at which the maximum mass gain occurs, the feed is converted at its maximum efficiency.  (Pigs in groups slightly lower temperature).  At temperatures below 4ºC increased feed consumption and decreased feed conversion occurs.  It is clear that heavy pigs are heat susceptible rather than cold susceptible.

 

Temperature and level of feeding

Growing pigs kept at a low feeding level are often most adversely affected by low temperatures (6.1ºC).  At high temperatures there are only small differences.

 

Temperature and body composition

The highest protein decomposition occurs at 15ºC – 23ºC.  At this temperature the fastest growth rate and best conversion are also obtained.  Better carcass length is obtained at 21ºC than at 12ºC.  Protein deposition is less adversely affected by temperature fluctuations than fat depositions.  Pigs are the fattest under thermo-neutral conditions.  A high fat deposition in this case is uneconomical due to poor feed conversion.

 

The effect of light

Light has no influence on mass gain and feed conversion.  Adequate space per pig must be provided.  The best results are obtained with small groups of pigs.  Basically, housing should be provided for:

• The non-productive flock. (Dry and pregnant sows and boars)
• The sow and her litter.
• Growing pigs.

 

Housing and dry sows should provide for

Easy identification of oestrus sign.  After weaning a sow should be housed within hearing and scent distance from a boar.  The accuracy of the immobilization reflex method when determining oestrus in sow by pressing on the sows, back, is increased by the presence of a boar.

Sows should be grouped to ensure the minimum fighting amongst themselves.  Apply individual feeding as far as possible particularly after mating as this has an important influence on the size of the litter.

Research indicates that sows that are mated during the hot summer months do not readily conceive.

It has been also found that sows farrowing during the warm summer months have smaller litter while the birth mass of the piglets are also lower compared with those born during the cooler seasons.

The first two weeks of pregnancy are the most critical because implementation occurs during the second week after fertilization.

High temperatures during the late stage of pregnancy increase the number of stillborn piglets.

Sows should be grouped according to the stage of pregnancy and they can feed in small groups with proper pens to sleep in.  The trees planted around the pens are a great help to avoid high temperatures.

 

The lactating sow

Critical stages in the housing of the lactating sow and litter is during farrowing time and also the first after farrowing.  Housing should provide for desirable temperatures and space in order to reduce the loss of piglets by stepping and lying on to a minimum.

The farrowing pen should have a concrete floor, a fan during the hot season and infrared lamps during the cold season.  Any other type of lamps or store can be used.

Bedding such as sawdust, shavings or grass hay may help to protect the piglets against excessive cold.  Desirable temperature for sows at this stage is 13 – 20ºC and the minimum temperature for piglets should be 32ºC.

Mortality of piglets during farrowing and the first few days after farrowing can be a high 33% and the farrowing pen should therefore be provided with a breeding crate inside.  This reduces the number of piglets’ injury by stepping and lying on, should the sow become nervous.  An iron rod or pipe around the inside wall of the farrowing pen, 20cm above the floor and 20cm from the wall can be help.

 

Growing pigs

Growing pigs represent the largest group that indicates the use of labour-saving system in respect of cleaning pens, feeding and watering.  Considerations of importance for optimum production are floor space per pig, size of the groups and temperature requirements.

 

Housing should provide for:

Water supply

Automatic water supply eliminates one of the most time-consuming tasks, with further advantages of fresh and uncontaminated water, which is important for disease control as well as for the best-feed utilization.

The system requires a lower capital investment than drinking through.

 

Clean lines

In contrast to the general belief pigs are clean animals which keeps their eating and sleeping quarters clean if the facilities are provided.

To ensure the least labour and high level of cleanliness, during passages which can be easily cleaned, and separate sleeping quarters can be installed.

Bedding can be eliminated for the greatest part of the year if the floors are well isolated against moisture and cold in the sleeping quarters.  This can be obtained by putting a layer of plastic 4 – 5 cm beneath the surface of the floor.  Sufficient floor space should be available at all times.

The relative fast physiological development of the pig complicates the continuous supply and optimal utilization of available floor space.

 

Temperature requirements

It is well known that factors such as growth rate, feed conversion carcass composition and general behaviour are influence by temperature.

During cold weather pigs use the energy supplied to keep themselves warm and less energy is available for growth, while in warm weather loss of appetite is evident.  Both too high and too low temperatures are detrimental to growth rate, feed utilization and finally to carcass composition.  Pigs will grow normally at temperatures that vary from 16 – 27ºC.

 

Provision feed

This is one of the times consuming daily tasks and must be carried out with the minimum labour and effort.  Feeding pens should be easily reached and must limit the wastage of feed.

Digestion and feeding

 

Introduction

Feeding costs represent about 70 to 80 % of the total costs in pig production and it is the largest single cost factor.  The pig is a single stomach animal and cannot utilize feeds with a high fibre content and is therefore less dependent on natural feeding resources.

It is important for efficient and profitable pig production that the pig receives correct treatment and feeding throughout the various growth stages.  Efficient feeding has a great effect on factors such as economic feed conversion, fertility, growth rate, and disease control and carcass quality.

 

Nutrients required by the pig

Carbohydrates

About 60 – 80% of pig ration basically consists of grain, rich in starch, which contributes to a large extent to the energy requirements of the pigs.  Growing pigs needs large quantities of energy.  Energy intake to a large extent determines the production rate and degree of fatness obtained.

Maize meal is the most important energy in pig rations in South Africa.  It contains about 80% TDN but is quantitatively and qualitatively low in protein.  Maize is especially deficient in lysine and triptophan.

 

Fibre

In comparison with ruminants, pigs are sensitive to too high fiber intake.  Older pigs can utilize more fiber in the ration than younger ones.  Insufficient fiber however may cause constipation and therefore bad performance.

Creep rations must contain about 3 to 4% fibre growth rations 5 to 7% (18 – 50kg live mass), finishing rations 7 to 9% (50 – 95kg live mass) and sow and boar rations up to 12%.  When grazing is available, attention must be given to this aspect.  Young succulent grazing must preferably be supplied to growing pigs and older quality grazing to non-pregnant sows and boars.

Nitrogen free extracts (NFE)

Products such as maize, barley, potatoes (starch) and whey (sugars) result in a good quality bacon.  Normally the TDN values as estimated for ruminants are used as a basis to compute the energy value of pig rations.  Creep rations should contain about 77.5% TDN and growing and sow rations about 75%.  Dry sow and boar meal must contain about 70% TDN.

 

Protein

The protein content of the ration determines the amount of nitrogen available for maintenance and tissue formation.  Of the 22 different amino acids 10 are considered as essential.  Special attention should be paid to lysine, methionine and triptophan.

Lysing is by far the most important amino acid because it is directly concerned with growth and meat production.  With the provision of amino acids, it must be kept in mind that the daily intake of essential amino acids should be optimal and in the right proportions at the right stage for optimum protein synthesis.

Animal proteins such as fish meal, carcass meal, blood meal and skimmed milk is excellent sources of high-quality proteins and these products is most important for balancing proteins in pig rations.  Due to the changing in biological value, preference is given to combinations rather than separate protein products in rations.

Although plant proteins have a lower quality, it is an important contributor to the total protein supply of a pig.  Maize as the most important energy source, contributes nearly half of the total proteins in pig rations.  Normally about 15% animal proteins are included in creep rations, 7,5% in growth rations and sow meal and 5% in dry sow and boar meal.

 

Fats

Although fats contain 2.25 times as much energy as protein and carbohydrates, it normally does not supply much of the total energy supplementation because the average fat content of pig rations is about 3,5%.  Products rich in fat can only be included in low percentages in the ration.  Oil cake meal and fishmeal with a low-fat content should be used.  Fat and oil in a ration are inclined to produce soft oily bacon.

Piglets (3 weeks and older) can utilize fats and oils as concentrated energy sources very well.  With an increased energy level by additional oils or fats, the protein level of the ration should be raised accordingly.

The feeding of oil cake meal and fishmeal results in the formation of soft bacon.  Where feeds high in fat can be obtained cheaply it should preferably be included in the growth stage.  In finishing rations it should be replaced with feeds that produce firm bacon (barley).  Soft bacon tends to harden in pigs, in other words soft bacon at 50kg can be firm at 95kg live mass.

 

Minerals

Although required in relatively small quantities, minerals are of utmost importance and sufficient quantities must be fed in correct rations.  Animal proteins like fishmeal and carcass meal are also important sources of calcium and phosphorous, while wheat bran and pollard are important sources of phosphorous.  Lucerne meal is an important source of calcium.  Minerals, especially micro-elements, are usually included in rations as chemical compositions.

Vitamins

Vitamin supplementation has lately become critical because pigs are bred and fed for maximum mass gains and most economic feed utilization.  This requires optimum vitamin in the correct balance.

Most feeds used to compile rations contain certain amounts of vitamins.  Some are less stable than others and therefore rations rely heavily on synthetic vitamins.  Special attention must be given to vitamins, A, D, E and some of the B complex for example riboflavin, niacin, pantothenic acid and B12.  Animal proteins are also good sources of vitamins of the B-complex.

Digestion in the non-ruminant

The term digestion includes all processes by which foods in the alimentary canal are prepared for absorption

1. Intake of food

Food is taken into the mouth by the lips, teeth and the tongue.  The upper lip and jaw of the pig are modified to form the snout which the pig to dig into the ground for food.  The lower jaw acts as a “spade” for food intake.

Fluid is obtained by means of suction.  The lips are kept closed except for the part inner the surface of the water, and the tongue is used to create a vacuum in the mouth.  Suckling piglets drink by creating an extensive vacuum in the mouth.  The tongue with its taste buds enables the animal to distinguish between tasty and bad food.  It also helps to rid the mouth to get rid of foreign objects in the feed.

1. Digestion in the mouth

This is mainly mechanical; chewing helps to break up large particles to make mixing and swallowing possible. 

1. Chewing

Teeth, especially the premolar and molar teeth, are utilized to grind the food in order to break it up into small pieces.  During chewing the jaws move up and down and from side to side.  The tongue helps to push in between the teeth.

1. Mixing the food with saliva

Before an animal can swallow dry food, it must be mixed and moistened with saliva.  Saliva is secreted by the different salivary glands and has the following functions:    

• It moistens the food so that it ca be swallowed easily
• It lubricates the mucous membranes of the mouth and pharynx, keeping it moist. 
• Saliva is alkaline with a pH of 7.3 and contains about 99 % water, the remaining 1 % consists of mucin, inorganic salts, the enzyme a-amylase and the complex lysozyme.  It is also antiseptic.
•  It serves as a solvent for food in process of tasting.
• It is important as a binding agent during the formation of a food bolus.
• Saliva a digestive enzyme called salivary amylase which changes starch to maltose.  This is not important in the domestic animals as it is in humans.
• Not much digestion occurs in the mouth, since the food is quickly swallowed and passed along the oesophagus to the stomach

1. Swallowing

 

The act of swallowing can be roughly be divided into three stages:

• Formation of a bolus:  After the food is chewed, a bolus is formed with the aid of the tongue.  This is done voluntarily and can be stopped at any time.
• Passage of the bolus through the pharynx.  When the bolus enters the pharynx an in voluntary contraction of the muscles in the pharynx in the pharynx forces the bolus into the oesophagus.
• Peristaltic movement of the oesophagus.  This is initiated by food in the oesophagus.  Peristalsis consists of alternative or rhythmic relaxation and contraction of the muscles in the wall of the oesophagus, forcing the bolus towards the stomach.  Liquids are carried about five times as fast by a squirting action of the mouth and pharynx.  Peristalsis in the opposite direction may also occur as in the as is known as retroperistalsis.
  1. Digestion in the stomach

 

The pig has a simple stomach of about with a capacity of about 8 litres, which functions not only as an organ for the digestion of food but also for storage.  In its food is mixed and moistened with digestive enzymes.  The ingested food enters the stomach through the oesophageal opening and mixing takes place by means of contractions of the stomach wall.

During this period of mixing the pylorus remains closed, but as soon as sufficient digestive juices have been secreted and digestion has advanced far enough, the pylorus opens and small quantities of stomach content, or chime, is forced into the duodenum.

Gastric glands in the mucosal lining of the stomach secrete certain substances collectively called gastric juice.  Gastric juice is a clear fluid which consists of water, mucus, salts, hydrochloric acid (HCl) and two enzymes, renin and pepsinogen.  Gastric glands include:

Cardiac and pyloric glands – They secrete mucus to protect the stomach lining against hydrochloric acid.

Fundic glands secrete – Hydrochloric acid        

                                                        Pepsinogen

                                                         Renin

1.  Functions of hydrochloric acid

• HCl activates pepsinogen to form pepsin
• It neutralizes the alkaline reaction of the saliva
• It supplies the acid medium which is required for the enzyme’s renin and pepsin
• It changes sucrose into glucose
• It has an antiseptic action and therefore prevention putrefaction in the stomach

1. Functions of pepsinogen

Pepsinogen is first changed to pepsin.  It then reacts on the proteins on the proteins in the stomach content and partly digest them into simpler substances called peptones

1. Functions of renin

The enzyme renin causes milk to curdle.  This happens when the soluble caseinogen of milk is changed to insoluble casein.  Renin plays a very important role in the stomachs of young suckling animals.

1.5.4    Digestion in the small intestine

Chyme enters the small intestine through the pylorus.  The chime is mixed by 

rhythmic segmentation of the small intestine.  This is a type of intestinal movement 

that does not move the contents along the intestines, but merely mixes it.  At intervals 

this rhythmic segmentation is interrupted by peristalsis which propels the ingesta

along the intestine, towards the anus.

 

Functions of the intestinal movements                                                  

• To mix ingesta with digestive enzymes
• To bring ingesta into contact with the mucous membrane for absorption
• To move ingesta through the gut
• To assist the flow of lymph and blood through the intestinal wall
• To expel faeces from the rectum.

 

The wall of the duodenum  are responsible by producing the enzymes and hormones necessary for together with its associated glandular structures (pancreas, liver and intestinal glands) are responsible by producing the enzymes and hormones necessary for the conversion of the partly digested products of the stomach into materials that can be absorbed by the body.  After intestinal digestion chime becomes chyle.  Chyle is a milky material that passes through the epithelium (lining) of the gut into the lymphatic vessels in the villi and from there into the bloodstream.

1. Digestion in the large intestine

Owing to the fact most digestion and absorption of food takes place in the small intestine, the contents of the large intestine consist mainly of indigestible waste products such as cellulose, hemicellulose and lignin.

No digestive juices are secreted in the large intestine, only mucus to lubricate the intestinal wall.  The large intestine acts as a reservoir of undigested material.  a further function is water absorption and concentration of the liquid content of the large intestine.  In pigs and other animals with simple stomachs digestion is continued in the large intestine by the action of bacterial enzymes.

The bacterial fermentation in the large intestine leads to the formation of substances which are waste products for the bacteria but are of value to the animal.  In this way animals with single stomachs are capable of utilizing some of the cellulose ingested.  Cellulose is digested to fatty acids and the bacteria is also responsible for the synthesis of the vitamin B-complex.

1. Accessory digestive glands and their functions

1. The liver

 

The liver is the largest gland in the body and is essential to life.  It performs several functions:

• It stores glycogen.  Glucose absorbed by the gut is changed to glycogen by the liver and stored there,
• It detoxifies poisons absorbed in the bloodstream
• It stores vitamins A, D, E & K.
• It stores copper and iron.
• The liver helps in forming blood especially in young animals.
• The liver secretes heparin, a substance that prevents blood from clotting.
• It is responsible for the synthesis of certain proteins such as plasma albumin, fibrinogen and prothrombin.
• It secretes bile which is collected and stored in the gallbladder until it is required in the small intestine.  Bile is a brownish-green viscous fluid containing bile salts and various organic substances.

 

Functions of bile

• Bile emulsifies fat – breaks up fat particles into small droplets
• It neutralizes the acid coming from the stomach
• It helps to create an alkaline medium in the duodenum, which is necessary for the absorption of fatty acids from the intestines.
• Bile salts help with the absorption of fat-soluble vitamins A, D, E & K.
• Bile has a binding effect on the chime, which slows down the passage of ingesta through the alimentary canal, thereby therefore ensuring sufficient digestion by the enzymes.
• Bile transports certain bile pigments to be broken down in the intestines and excreted.

 

After the bile salts have acted on the chime they are reabsorbed in the last part of the alimentary canal.  They enter the bloodstream and are transported via the liver to be excreted in the bile again.

1. The pancreas

The pancreas has two functions and a double structure:

• The exocrine portion; secretes pancreatic juice
• The endocrine portion (Islets of Langerhans); secretes hormones such as insulin.

Pancreatic juice is a clear, distinctly alkaline fluid which contains many enzymes.  The secretion of pancreatic juice is controlled by the hormone secretin.

 

Functions of pancreatic juice

• The high sodium bicarbonate content of pancreatic juice neutralizes the acid chime from the stomach.
• The proteolytic enzymes in pancreatic juice namely, trypsin, chymotrypsin and carboxypeptidase changes proteins to peptones and peptides.
• Pancreatic lipase changes emulsified fats to glycerol and fatty acids.
• Pancreatic amylase has a similar action to that of ptyalin in the saliva and converts starch to maltose

1. The intestinal glands

Intestinal juice, or succus entericus, is the name given to the specific secretions of a number of small glands which is widely distributed in the lining of the small intestines.

The most important of these glands are the crypts of Lieberkühn and Brunner’s glands.  Secretion takes place as a result of food intake and the mechanical stimulation of the intestinal lining of food.  The hormone enterocrynin secreted by the liver also stimulates the secretion of intestinal juice.

 

Functions of the intestinal juice (succus entericus)

• Enterokinase, which activates trypsinogen to trypsin
• Maltase which converts maltose to two molecules of glucose.
• Sucrase which converts sucrose to glucose and fructose.
• Lactase which converts lactose to glucose and galactose
• Lipase which digests fats by changing them into glycerol and fatty acids
• Peptidase which peptones down to amino acids