Livestock Products
Senior 1 · Agriculture
Livestock Products
Lesson 2 of 4
20 min
Let's begin
Roasted pork, known across Rwanda as akabenzi, has become one of the country's most popular meats, and pig keeping has grown to supply it. Pigs are efficient: a sow can give birth to about ten piglets at a time, twice a year, and pigs turn feeds that people do not eat, such as maize bran, brewery waste grain and kitchen leftovers, into meat within months.
There is an old saying among pig farmers that "everything is used except the squeal". In this lesson you will see why: you will identify the products and by-products of the pig and their uses, and calculate how much meat a pig gives.
It depends on the kind of pig farm:
| Product | Description and use |
|---|---|
| Pork | Fresh pig meat. High in protein and B vitamins; fattier than beef, depending on the cut. |
| Processed pork | Ham, bacon and sausages: pork that has been salted, smoked or minced so that it keeps longer and sells for more. |
| Lard | Pig fat melted down and strained; a cooking fat. |
| Weaners and breeding stock | Live young pigs, gilts and boars sold to other farmers. |
| By-product | Uses |
|---|---|
| Skin | Unlike cattle, pigs are usually dressed with the skin left on, so much of it is eaten (roasted pork rind, crackling). It can also be tanned into a soft leather for gloves and linings, or boiled to make gelatin. |
| Bristles | The stiff hairs make brushes, including paint brushes. |
| Blood | Blood sausage; dried into blood meal for feed and fertiliser. |
| Bones | Bone meal (calcium and phosphorus); gelatin; soup. |
| Intestines | Cleaned and used as natural casings for sausages. |
| Offal | Liver, kidneys, heart; the feet (trotters) and head are also eaten in many places. |
| Manure and urine | A rich fertiliser once composted; an excellent feed for a biogas digester, which gives cooking gas and a slurry for the fields. |
Pork must always be cooked right through. Undercooked pork can carry the cysts of the pork tapeworm, which can infect people and cause serious illness. Buy pork that has been inspected at a proper slaughterhouse.
Because a pig has no large rumen and is dressed with its skin on, it has a higher dressing percentage than cattle, typically around 70–75%.
Worked example
A fattened pig weighs 90 kg live and dresses at 72%.
A sow in Rwamagana has 2 litters a year and weans 9 piglets per litter. The farmer fattens all of them to 90 kg live (72% dressing).
(These figures are illustrative: real litters, survival and growth vary from farm to farm.)
Tip
Memory hook, pig by-products "Some Butchers Buy Big Intestines Mostly": Skin, Bristles, Blood, Bones, Intestines, Manure.
Exam technique: in percentage questions, turn the percentage into a decimal first (72% = 0.72), then multiply. Always give the unit (kg) in the final answer.
What is the main product of a pig breeding farm, and how does it differ from that of a fattening farm?
Solution: A breeding farm's main product is weaners (young pigs) sold to other farmers. A fattening farm's main product is pork, from pigs grown to slaughter weight.
State one use of each: (a) pig bristles; (b) pig intestines; (c) pig manure.
Solution: (a) making brushes; (b) natural sausage casings; (c) fertiliser after composting, or feed for a biogas digester.
Explain why pigs usually have a higher dressing percentage than cattle.
Solution: Pigs have a simple stomach, so their gut and its contents are a smaller share of body weight than a ruminant's, and pigs are dressed with the skin left on, so the skin counts as part of the carcass.
A pig weighing 110 kg live has a dressing percentage of 75%. What is its carcass weight?
Solution: 0.75 × 110 = 82.5 kg.
Why must pork always be cooked thoroughly?
Solution: Undercooked pork may contain the cysts of the pork tapeworm, which can infect people and cause serious disease; thorough cooking kills them.
Summary
Sources and credits
The Rwandan examples, worked examples and practice questions are written by Ganzaa.
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
