INTRODUCTION
Good feeding is the single most important factor in profitable pig production. It has already been stated that 80% of the cost of producing a baconer or porker pig is the cost of food. In any pig unit consisting of breeding and fattening pigs, four fifths of the food used in the unit is consumed by the growing and fattening animals, and one fifth by the breeding pigs; the sows and boars.
The other factor to remember in pig production is that feeding is an exact science. The British company B.O.C.M. began a hybrid pig breeding programme in 1963 because they found that the commercial pigs available on farms in the U.K. at that time, were unable to make the best use of the improved feeds that were being marketed. The science of pig-feeding had advanced faster than the science of pig-breeding. Furthermore, porker and particularly baconer pigs have to comply with very exact standards of grading in order to make the best price; standards cover the weight of the pig and the amount of fat on the carcass. The points to remember about feeding pigs are:
- Pigs are very greedy animals and will eat large amounts of food if they are fed ad lib (as much as they can eat e.g. fed to appetite);
- Pigs will eat almost anything, but for modern bacon and pork production they are fed on meals. These meals are based on cereals, the basic cereal in Africa being maize and in Europe and U.K. being barley. All good pig meals are balanced for carbohydrate, protein, minerals, vitamins and other additives;
- Pigs for pork and bacon are slaughtered before they have reached maturity – before they have finished growing. They have to be fed for growth, lean meat and fat production all at the same time;
- Pork and bacon pigs have to be within the weight and backfat ranges laid down for their respective grades. If, when they are sold for slaughter, they are the wrong weight or too fat they will yield a much lower price; and
- Pig feeding has to be a balance between feeding ad lib (to appetite) in order to get fast growth, and rationing the meal to achieve the best grades and the best price. Rationing also reduces the amount of meal eaten by the pig and the cost of the finished animal.
It has been found by experiment that reducing the food from 8kg to 1,6kg up to porker weight, and from 2,8kg to 2,5kg up to baconer weight will reduce the backfat thickness by 1% and the growth rate of the pig by 10%. Increasing the protein content of the ration, and particularly the lysine content, will increase the amount of lean meat on the carcass.
Pig meals are available from all animal food merchants, and there are two types:
- A meal which provides a completely balanced ration for a particular type of pig e.g. growing-pigs, finishing pigs (between pork and bacon weight), breeding sows etc. These meals provide all the nutrients required by the pig, they are ground to the correct fineness, and properly mixed. The pig man nly has to feed the correct quantity.
- Pig concentrate meals are mixed with maize meal to give a balanced ration for a particular type of pig. By using concentrate meals, the farmer can make use of his home grown maize and this will reduce the cost of the ration fed to his pigs, although the reduction in cost is not great. Very large pig producers can buy in all the ingredients required and mix their own rations on the farm, and this will reduce the cost of the rations, although the farmer must have a sound knowledge of pig nutrition and be able to obtain a regular supply of all the ingredients.
| TABLE 1: THE FOLLOWING IS A LIST OF SOME OF THE PIG FEEDS AVAILABLE IN SOUTHERN AFRICA, TOGETHER WITH AN ANALYSIS OF THE MAJOR NUTRIENTS: | ||||||
| CRUDE PROTEIN % | FAT % | CRUDE FIBRE % | ASH % | CALCIUM% | PHOSPHORUS % | |
| Pig Creep Pellets | 19.0 | 5.5 | 4.0 | 5.7 | 0.9 | 0.8 |
| Pig Growth Meal | 17.0 | 3.4 | 4.1 | 6.4 | 1.0 | 0.7 |
| Pig Finisher Meal | 15.4 | 3.7 | 4.0 | 5.6 | 0.9 | 0.7 |
| Brood Sow Meal | 15.0 | 4.0 | 4.0 | 7.0 | 1.0 | 0.8 |
| Brood Sow Concentrate | 25.5 | 3.0 | 6.7 | 15.0 | 2.7 | 1.5 |
| High Protein Pig Concentrate | 38.0 | 3.0 | 5.5 | 16.5 | 3.8 | 1.4 |
| CRUDE PROTEIN % | FAT % | CRUDE FIBRE % | ASH % | CALCIUM% | PHOSPHORUS % | |
| Pig Growth/Finisher Concentrate | 30.5 | 2.6 | 7.0 | 14.0 | 2.7 | 1.3 |
| Pig Creep Concentrate | 36.0 | 6.5 | 6.5 | 11.8 | 2.3 | 1.2 |
One can tell that the concentrate meals are high in protein. These meals are designed to be mixed with maize meals at the rate of 2 parts of maize meal (by volume) to 1 part of concentrate meal e.g. 2 bags of maize meal and 1 bag of concentrate mixed together. Mixing should be done in a proper mixer attached to a hammer mill, or it can be done by turning the mixture several, times with a shovel on a cement floor.
In order to give you an idea of the different ingredients used in pig meals, the following mixtures were used to feed pigs.
| TABLE 2: INGREDIENTS USED IN PIG FEED | ||||
| Ingredient | Creep Feed % | Sow Meal % | Grower Meal % | Finisher Meal % |
| Maize Meal | 56.5 | 71.25 | 61.5 | 58.5 |
| Wheat Feed | 9 | 8 | 15 | 24 |
| Meat and Bone Meal * | 3 | 1 | 2 | 1 |
| Extracted Soybean Meal | 22. | 9 | 16.5 | 12 |
| Heated Soybean Meal | 5 | – | – | – |
| Blood Meal | – | 1 | 1 | – |
| Cottonseed Meal | – | – | 2 | |
| Sunflower Seed Meal | – | 6 | – | – |
| Limestone Flour | 0.5 | 1.5 | 1.5 | 1 |
| Monocalcium Phosphate | – | 0.75 | 0.5 | 0.5 |
| Mineral and Vitamins | 4 | 1.5 | 2 | 1 |
| 100 | 100 | 100 | 100 | |
| * Meat and Bone Meal can be replaced by extra Extracted Soybean Meal. |
In contrast, the following ingredients are used in pig meals in the UK:
| TABLE 3: INGREDIENTS USED IN PIG FEEDS IN THE UK | |||
| Ingredient | Creep Feed % | Sow and Weaner Meal % | Finisher Meal % |
| Barley Meal | 20 | 55 | 60 |
| Wheat Meal | 10 | 20 | 35 |
| Wheat Bran | 20 | 10 | – |
| Flaked Maize | 20 | – | – |
| White Fish Meal | 10 | 7.5 | 2.5 |
| Soybean Meal | 10 | 7.5 | 2.5 |
| Dried Grass | 5 | – | – |
| Dried Skim Milk | 5 | – | – |
| 100 | 100 | 100 |
VITAMIN E AND SELENIUM DEFICIENCY
Pigs need vitamin E for growth and reproduction and the vitamin is usually supplied by the cereal part of the ration. However, in Europe the vitamin can be reduced in cereal crops by bad weather at harvest and artificial drying of the crop. In Zimbabwe it has been found that the level of the vitamin has been reduced in cereals, probably due to more intensive cropping. Vitamin E deficiency causes sudden death due to liver damage, heart damage, jaundice, and muscular degeneration in growing pigs and breeding problems and loss of milk in sows. It has been discovered over the past few years that vitamin E cannot function properly in the food unless selenium is also present. In other words, shortage of selenium causes pigs to die of vitamin E deficiency. It is considered essential in Southern Africa to add both vitamin E and selenium to all pig feeds.
SOYBEAN MEAL
Soybeans have a high biological value and provide an ideal protein for both pigs and poultry. Extracted soybean meal, made from the residues after the oil has been extracted from the beans, is used as a major source of protein in pig meals all over the world. However, raw soybeans contain factors that are toxic to pigs, and they also contain a chemical called a trypsin inhibitor which prevents the action of the enzyme trypsin which is used in the process of digestion. The heat which is used in the process of extracting the oil from the beans destroys the trypsin inhibitor and the other toxic substances which would cause depressed appetite and slow growth in pigs. Due to experiments carried out at the P.I.B. Farm in Zimbabwe, large pig producing farmers can now process their own soybeans using a special processing plant. The equipment involves heating the beans as they move through a rotating cylinder, and allowing them to cool slowly in lagged containers. Heat is supplied by gas jets and the beans are roiled forward above the jets. The temperature of the beans emerging from the cylinder must be at least 1100 °C, and they must be cooled slowly so that they continue to cook after leaving the cylinder. The equipment for treating soybeans is available in the Southern Africa.
2. CREEP FEEDING
This means allowing little pigs access to meal or pellets while they are suckling the sow. The reasons for creep feeding little pigs are:
- To reduce the age of weaning. Pigs on suckling alone are weaned at 8 weeks old, whereas those on suckling plus creep feed can be weaned at 5 – 6 weeks after birth. The sow comes on heat earlier, and produces more litters during her lifetime;
- The sow is kept in better condition because the little pigs are less demanding on her milk. By weaning, the pigs are eating meal or pellets and require less milk from the sow;
- The pigs grow faster and are heavier at weaning than those that have not been creep fed; and
- The digestive system of the little pig is accustomed to solids at weaning, and the change over from milk to solids is carried out gradually rather than abruptly.
| Ad lib: unrestricted supply of feed. |
The creep feed should be introduced to the little pigs at one week old and fed ad lib until they are 8 weeks old, which is 2 – 3 weeks after they have been weaned. At weaning the pigs should weigh about 9kg, and weaning is done by removing the sow and leaving the little pigs with their creep feed. After 8 weeks of age, the pigs can be changed to growers meal, and this should be done gradually over a period of a week. At 8 weeks old the pigs are eating ad lib creep feed and at 9 weeks they are eating ad lib growers meal.
The creep feed pellets or meal should be fed in a trough which is protected by bars so that the sow cannot eat the feed; only the little pigs can have access to the creep feed.
3. FEEDING FATTENERS
Once the little pigs have been weaned, there are two ways of feeding them for pork or bacon production; feeding to appetite (ad lib feeding) or rationing the food intake. The advantages and disadvantages of the two systems were discussed above. The system of feeding which a farmer uses will depend on the market that he is supplying with his pigs. Farmers in the U.K., producing heavy hogs under contract for the Walls Pig Company, feed ad lib, because they are aiming for maximum weight in the shortest possible time, and they do not have to worry about a grading system, as heavy hogs are not graded. Once these pigs are slaughtered, the skin is removed and sold for the manufacture of pig skin shoes. All excess fat is trimmed from the bacon and hams, and the fat is used for the manufacture of ice cream. In other parts of the world, farmers supplying local markets do not have to worry about grading of their pigs, but those farmers supplying pigs for the production of quality pork and bacon, have to comply with very exact grading standards.
Grading is so important in the production of quality pigs, that most farmers use a compromise between ad lib feeding and rationing. Pigs are fed ad lib meal up to a certain age or weight, and then they are rationed until slaughter. This method gives rapid live-mass gains and good food conversion during the early part of the pig’s life, and uses less food and produces good grades when the pigs are slaughtered. A lot of research is being done in developed countries to produce a pig that will grow to bacon weight on ad lib feeding, and at the same time produce good grades, but so far, this has not been achieved. Pigs that are slow to fatten are also slow growers, while those that grow quickly, produce too much backfat for the modern market.
RATIONING ON WEIGHT
Once the little pigs have been weaned, they are fed ad lib on creep feed meal or pellets until they are 8 weeks old, when they are changed gradually over to growers meal with a crude protein of 17%. Once they reach 20kg live-mass, they are put onto a daily ration, fed in two feeds each day, as follows:
| TABLE 4: FEED CONVERSION TO LIVE MASS | |
| Live-mass (kg) | Amount of feed per day (kg) |
| 20 | 1.0 |
| 25 | 1.2 |
| 30 | 1.45 |
| 35 | 1.65 |
| 40 | 1.85 |
| 45 | 2.0 – 2.05 |
| 50 | 2.0 – 2.20 |
| 55 to bacon weight | 2.0 – 2.27 |
When the growing pigs reach 55kg live-mass, they are changed over from growers meal to finisher meal with a crude protein of 15 – 16% and fed on this until slaughter. The change-over of meals should be done gradually over a period of 5 days.
RATIONING ON AGE
This is a simpler system than the one above-mentioned, and of course it must be used in pig units where the pigs are not weighed each week. The little pigs are changed over from creep feed to growers meal at 8 – 9 weeks old and are fed ad lib, until they are 10 weeks old. During the 11th week, feed is restricted to 1,3kg per pig per day. From the 12th week onwards the meal is increased by 110g per pig per week, up to a maximum feeding level of 2kg a day in the summer and 2,3kg a day in winter.
All ad lib feeding should be done using self-feed hoppers, and rationed meal should be fed in troughs, making sure that each pig has enough space to feed at the trough.
4. FEEDING SOWS AND BOARS
There are four distinct periods in the life of a breeding sow, and a good sow producing two litters a year will go through each phase twice every year.
These are:
- The period immediately after weaning when the sow is being dried off to prevent further milk production;
- The period when the sow comes on heat and is served, normally 2 – 5 days after weaning;
- The period when the sow is pregnant; and
- The period when the sow is lactating – producing milk and feeding her litter.
Sows are fed on brood sow meal or sow and weaner meal with a crude protein of 15%. At weaning, the sow is starved of feed for 24 hours and given a restricted supply of water. After 24 hours, she should be fed 3,7kg of meal per day until she has been served. This high rate of feeding is to ‘flush’ the sow, so that she will produce the maximum number of eggs at ovulation. These eggs are fertilized by the boar at service, and it is at this period that the size of the litter is determined. Once the sow has been served, the ration should be reduced, and the following levels fed during her pregnant period:
First 12 weeks of pregnancy 1,8 – 2,7kg per day.
From 12 weeks to farrowing 2,3 – 3,2kg per day
The actual amount fed will depend on the size and condition of the sow.
Immediately after farrowing, the sow is given only water and a very small amount of meal. The meal is then increased each day until, at the end of the first week the sow should be getting the following:
| Feed for Sow | Additional Meal per Piglet |
| 1.0 – 2.0kg | 0.45kg per day |
A medium sized sow with 10 piglets would be fed
1.5 + (0.45 X 10) = 1.5 + 4.5 = 6.0kg per day
The maximum amount of meal to feed to a lactating sow is 6,5kg per day.
BOARS
Boars should be kept in a lean, active condition in order to prolong their useful life. Those that are overfat become lazy and either stop serving their sows or take a very long time to do so. Rations for a boar should be 1.8 – 2.3kg of sow meal a day depending on their size, and they should be given plenty of exercise if possible.
5. ALTERNATIVE SYSTEMS OF FEEDING
The exacting standards of grading for quality pork and bacon production can only be met by feeding the correct quantities of a balanced cereal/protein ration. The parts of the world where cereal is a basic human foodstuff, it is doubtful if any increase in quality pig production can be justified. since they have a simple stomach, pigs eat the same kinds of food as humans do, and the protein produced by pig products such as bacon and pork is a luxury which developing countries cannot afford. The expansion of pig meat production, particularly in African agriculture, should come from pigs fed on swill and other by-products – in other words, foods that are not already consumed by human. The pig has the ability to grow on marginal foods and to provide a valuable supply of meat for home consumption. This is particularly so in the case of the indigenous pig, or crosses between it and the more sophisticated breeds.
LEHMANN SYSTEM
With this system, after weaning the pigs, the meal ration is increased up to 1,5kg per pig per day. Once the pig has reached 25kg in weight, the meal is maintained at a daily ration of 1,5kg, and other foods are introduced and fed to appetite. Foods which can be used are as follows:
POTATOES
Either cooked or fed raw. Raw, green potatoes must never be fed to pigs as these contain alkaloids and are poisonous. Small potatoes or chats, which are too small for sale are ideal, and are best fed after being boiled.
SWILL
Which is a mixture of waste foods should be boiled before feeding. Mixed swill can sometimes be obtained from hotels, army camps and other places where large amounts of food are processed every day for human consumption. Swill must be boiled before feeding to pigs in order to prevent any infectious diseases being passed on through infected meat in the swill.
OTHER SUITABLE FOODS
Are maize meal, sweet potatoes, sorghum, stale bread, masese (by-product of opaque beer manufacture), peaches, mangoes, and the by-products from cheese making such as whey and skimmed milk.
Small amounts of the following foods can be fed each day:
Green leaves from cabbages, bamboo and banana plants, cooked meat residues and blood.
In the UK and Europe, fodder beet is grown as a crop on some farms for feeding to pigs, particularly breeding pigs and heavy hogs. Both the tops and the roots of the plant are eaten, and in some cases farmers graze their pigs over the crop in the field.
MEAL EQUIVALENTS
1kg of meal is equivalent to: 1.8kg potatoes
2.3kg fodder beet
5.5 litres of whey
3.7 litres of skimmed milk
Good daily grazing on short, green grass
SKIMMED MILK
Is a very good feed for pigs, and should be fed either fresh or allowed to sour before feeding. Do not feed fresh skim one day and sour skim the next day as this will upset the pigs. If pigs are fed litres of skim daily from weaning to bacon weight, this can be supplemented with maize meal and minerals and vitamins. Skim should be fed regularly rather than just occasionally.
The main essential with pigs is to be very careful in changing their diet. Any changes should be done gradually to give the digestive system of the animal time to adjust to the change.
FOODS THAT ARE OF NO USE TO PIGS:
Banana Skins, Citrus Peel, Tea Leaves, Paper, Feathers, Bones.
FOODS THAT ARE DANGEROUS TO PIGS:
Raw green potatoes, dead flowers, dried senecio, munga containing ergot, salt, and any grain contaminated with diplodia and fusarium moulds.
