Livestock Products
Senior 1 · Agriculture
Livestock Products
Lesson 3 of 4
20 min
Let's begin
Every morning, trays of eggs leave small farms around Kigali, Bugesera and Musanze for shops, schools and hotels. A laying hen can produce an egg on most days, so a flock of a few hundred hens gives its owner something to sell every single day, which is why many young farmers start with poultry.
Eggs are only one output. In this lesson you will identify all the products of poultry, learn the parts of an egg, and measure how well a flock is laying.
| Product | From | Notes |
|---|---|---|
| Table eggs | Layers, village hens, ducks, quails | Eggs for eating. They do not need to be fertile: a hen lays eggs whether or not a cock is present. |
| Hatching (fertile) eggs | Breeding flocks that include cocks | Sold to hatcheries or set under a broody hen; they hatch into chicks in about 21 days. |
| Day-old chicks | Hatcheries | Sold to farmers to start new flocks of layers or broilers. |
| Poultry meat | Broilers, cockerels, spent hens (layers at the end of their laying life), ducks, turkeys | Sold live or dressed (slaughtered, plucked and cleaned). Lean, high-protein meat. |
Knowing the parts of an egg helps you judge its quality and explains how it is protected.
| By-product | Uses |
|---|---|
| Poultry manure (droppings mixed with bedding, called litter) | A very rich fertiliser, higher in nitrogen than cattle manure. Fresh droppings are strong enough to scorch young plants, so compost them first. Also used in biogas digesters. |
| Feathers | Filling for pillows and mattresses, decorations and crafts; processed under heat and pressure into feather meal, a protein ingredient for feed. |
| Edible offal | Gizzards, livers, hearts, necks and feet, sold cheaply and widely eaten. |
| Blood and inedible offal | Processed into meals for animal feed or fertiliser. |
| Eggshells | Crushed and fed back to laying hens as a calcium supplement, or added to compost. |
| Cracked and dirty eggs | Cannot be sold as table eggs; used at home or by bakeries if still fresh. |
A farmer judges a laying flock by its hen-day egg production, the percentage of hens that laid on a given day:
Hen-day egg production (%) = eggs collected in a day ÷ number of hens in the flock that day × 100
Worked example
A cooperative in Bugesera has 250 layers and collects 205 eggs today.
A sudden drop in hen-day production warns the farmer of a problem: disease, poor feed, too little water, stress, or old hens that should be sold as spent hens.
Birds are dressed with the skin on but without feathers, head, feet and guts. Their dressing percentage is about 75%, higher than that of cattle. A broiler of 2.2 kg live gives about 0.75 × 2.2 = 1.65 kg of dressed carcass.
Tip
Memory hook for the egg, from outside in: "Can Some Mothers Always Find Chicks' Yellow Germs?" Cuticle, Shell, Membranes, Air cell, Fluid white (albumen), Chalazae, Yolk, Germinal disc.
Exam technique: in production calculations, check your answer makes sense: hen-day production can never be more than 100%, because a hen lays at most one egg a day.
Distinguish between a table egg and a hatching egg.
Solution: A table egg is for eating and need not be fertile; hens lay without a cock. A hatching egg is fertile (from a flock with cocks) and is incubated to produce a chick.
What is the function of the chalazae?
Solution: They are twisted cords of albumen that hold the yolk in the centre of the egg.
A farmer has 400 hens and collects 312 eggs in one day. Calculate the hen-day egg production.
Solution: 312 ÷ 400 × 100 = 78%.
Why should fresh poultry manure be composted before it is put on a vegetable bed?
Solution: Fresh droppings are so rich in nitrogen that they can scorch (burn) young plants; composting makes the nutrients gentler and kills germs.
What is a spent hen, and what is done with it?
Solution: A layer at the end of its productive laying life. It is sold for meat.
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.
