Animal Nutrition, Feeds, and Feeding Practices
Animal Nutrition, Feeds, and Feeding Practices tests feed classification, nutrient functions and ration formulation. You must distinguish roughage from concentrate, maintenance from production needs, and a balanced ration from a random mixture.
Core rules
- Water is the most limiting nutrient; a dairy cow may drink 60–100 litres daily depending on milk yield and weather.
- Energy is usually first-limiting; protein supplies amino acids. Minerals and vitamins are needed in small amounts but cause serious disease when deficient.
- Roughages are bulky, high-fibre feeds such as grass, straw and silage. Concentrates are low-fibre, nutrient-dense feeds such as maize, soybean meal and oil cakes.
- A balanced ration supplies energy, protein, minerals and vitamins in the right proportion for maintenance and production.
- Urea can be fed to ruminants as a non-protein nitrogen source, but never to pigs or poultry. Untreated straw is low in protein and digestibility; urea treatment improves it.
Worked example
Make a 16% crude protein concentrate from maize (9% CP) and soybean meal (45% CP). Using Pearson square: soybean meal parts = 16 − 9 = 7; maize parts = 45 − 16 = 29; total = 36. Therefore soybean meal = 7/36 = 19.4% and maize = 80.6%. The result is a protein mix, not a complete ration; minerals and roughage must still be added.
Traps
Do not treat crude protein (CP) as digestible crude protein (DCP). Do not feed urea to monogastrics. Do not increase concentrate suddenly; it can cause rumen acidosis. Do not ignore water and mineral mixture.