Feeding of Livestock: Feeds, Fodder and Nutrient Requirements
Domain 4: Feeding of Livestock: Feeds, Fodder and Nutrient Requirements
This domain tests feed classification, nutrient functions, fodder preservation and simple ration calculation. The exam often gives a milk yield and asks for roughage and concentrate quantities, or asks which feed is deficient in a nutrient.
Feed classes
- Roughages: green fodder, hay, straw and silage; high fibre and low energy per kg. Legume fodders such as berseem and lucerne are richer in protein; cereal fodders such as maize and sorghum are richer in energy.
- Concentrates: energy feeds (maize, rice bran, molasses) and protein feeds (groundnut cake, soybean meal, cottonseed cake, the last used in limited amounts because of gossypol).
- Mineral mixture and common salt are not optional extras in a productive ration.
- Water is the cheapest nutrient and limits milk yield if restricted.
Preservation
Hay is dried fodder, preferably made from leafy legumes before flowering. Silage is fermented green fodder at 60 to 70 percent moisture; maize is the standard crop. Wilting, chopping, rapid filling and airtight sealing are essential.
Worked example
A crossbred cow gives 15 L milk per day. Using the field thumb rule of maintenance plus 1 kg concentrate per 2.5 L milk, concentrate = 15 divided by 2.5 = 6 kg per day, plus about 25 to 30 kg green fodder and 4 to 5 kg dry roughage, with mineral mixture. Reason: the rule covers maintenance in the base allowance; if the cow is pregnant or gaining condition, adjust upward. In an exam, if a table of requirements is given, use the table, not the thumb rule.
Traps
Confusing DCP (digestible crude protein) with TDN (total digestible nutrients); feeding urea to young calves or mixing it carelessly; sudden concentrate increase causing acidosis; and lush legume feeding causing bloat.