Animals

Animal nutrition

Animal nutrition at this grade is the ruminant gut in detail, and a ration that matches maintenance and production.

CAPS

Grade 12 · Agricultural Sciences · Animals

Agricultural Sciences splits animals from plants, soil and management.

The papers
Paper 1 is animal nutrition, animal production, reproduction and protection. Paper 2 is soil science, plant studies, and agricultural management. Each paper is 150 marks.
How to write it
Use the farming term, then the reason: a deficient mineral, a symptom, a management practice, and why it changes the yield or the health of the animal. A list with no cause does not explain.
How a marker reads it
A common mix-up is to feed a high-producing cow on maintenance veld alone, or to drop roughage because concentrate looks modern.

Data-response questions want you to read the table first. A general paragraph about farming that ignores the numbers scores as if you did not see them.

Diagram

Worked theory

Worked theory. A dairy cow in early lactation. She is producing milk and, if the ration is only veld, she pulls calcium and energy out of her own body and loses condition. A production ration adds energy and protein on top of roughage, so the microbes still have fibre and the udder has the extra. All concentrate and no roughage makes the rumen too acid. All roughage and no concentrate makes a thin cow and a small milk cheque. The ration is two jobs, maintenance and production, served to a four-part stomach.

More worked examples

A cow in the first month of milk
She is producing 20 litres a day on veld that only covers maintenance. She loses condition because the litres come off her back. Add 4 kg of a production concentrate and keep the roughage, and the litres come from the ration instead. Drop the roughage and feed concentrate only, and the rumen goes acid and she goes off her feed. The 20 litres needed both parts: fibre for the microbes, extra energy for the milk.
A dry cow and a cow in milk
A farmer’s plan feeds a dry cow about 80 percent roughage and 20 percent concentrate. She is not making milk, and the rumen needs fibre. When she calves, the plan shifts toward 60 percent roughage and 40 percent concentrate so the litres have energy behind them. Those ratios are this farmer’s plan, not a law of nature. Dropping the roughage to chase more litres makes the rumen acid. The milk then falls anyway.

In ordinary words

A cow’s stomach has a rumen, where microbes ferment fibre, a reticulum, an omasum that absorbs water, and an abomasum that works like a true stomach with acid and enzymes. The microbes need a steady supply of roughage. A ration has a maintenance part, to keep the animal alive, and a production part, for milk, growth or pregnancy. Protein, energy and minerals have to be in the production part or the product simply does not appear. A monogastric animal still cannot be fed as if it had a rumen.

In South Africa

A dairy ration card, roughage plus concentrate, is the worked theory written as kilograms.

Part 1 / 4

What it is

Animal nutrition at this grade is the ruminant gut in detail, and a ration that matches maintenance and production.

Ruminant and monogastric digestion — Diagram

More worked examples

Board walkthroughs on this topic. Open one, copy the working, then try the next.

Example 1 / 20

Use the Pearson square to mix maize (8% CP) and soybean meal (44% CP) to get a 16% CP ration.

4. Step-by-step working

01
Subtract
Maize parts=44−16=28; soybean parts=16−8=8.
02
Divide
Total 36 parts: maize 2836=77,8%; soybean 836=22,2%.

How we got there

Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

Explain in another language · 11

1. What is the question asking?

Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Use the Pearson square to mix maize (8% CP) and soybean meal (44% CP) to get a 16% CP ration.

In other words — as if you have never seen this before

If you have never seen this before: Subtract diagonally. We will name a method in words, write the formula with no numbers, then substitute one line at a time.

2. What do we already know?

8% and 44% → 16%.

3. Which method — and why this one?

Subtract diagonally.

4. Step-by-step working

01 / 05
Subtract
Maize parts=44−16=28; soybean parts=16−8=8.
Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.
02 / 05
Divide
Total 36 parts: maize 2836=77,8%; soybean 836=22,2%.
Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.
03 / 05
Step G — Sense-check the size
Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.
Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.
04 / 05
Step F — Box the answer with its unit
77,8% maize, 22,2% soybean meal.
Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.
05 / 05
Step H — What the marker is looking for
On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.
Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

5. The answer

77,8% maize, 22,2% soybean meal.

Copy onto your answer sheet — in this order

Answer: 77,8% maize, 22,2% soybean meal.

6. Check it like a marker

Check: 0,778×8+0,222×44=6,22+9,78=16% ✓

7. A trap first-timers fall into

First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

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Animal production

Agricultural Sciences

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