Agricultural Science (AS)·Animal science · NSSCAS 4.2a
Animal nutrition: feed components, nutrients & food tests
Narrated lesson · press play
On one farm near Gobabis, beef cattle stand at a feedlot trough eating a carefully mixed ration; on the next farm, cattle roam the open veld grazing whatever grass they find. Which animals grow faster, and why? To answer that we must open up animal feed itself — the water, carbohydrates, proteins, fats, vitamins, minerals and fibre inside it, the tiny trace elements that keep an animal healthy, and the simple lab tests that tell a farmer exactly what a feed contains.
What you'll learn in this lesson
By the end you should be able to (NSSCAS Agricultural Science (AS) 4.2a):
- Describe the main components in animal feed: water, carbohydrates, proteins, lipids, vitamins, minerals and fibre (roughage), and the role of each
- Describe the structure of carbohydrates (monosaccharides, disaccharides and polysaccharides), proteins (amino-acid chains) and lipids (glycerol and fatty acids)
- Describe the roles of the trace elements cobalt, copper and selenium, and of vitamin E, in an animal's diet
- Describe the consequences of cobalt, copper, selenium and vitamin E deficiency, and how each is treated
- Discuss and compare feedlot and pasture feeding regimes and their effect on farm-animal productivity
- Explain what is meant by the digestibility of animal feed
- Explain the tests for reducing sugars, non-reducing sugars, proteins and fats in animal feeds
Loading your lesson…
You're watching a free 3-minute preview — create a free account to keep going.
Quick revision
Revise this in 5 minutes
Miss Elina and Mike talk through the whole topic — with the figure and working drawn live.