Dairy Animal Nutrition and Feeding Practices
Nutrition carries a large share of marks because feeding is the biggest cost on a dairy farm. Expect questions on dry matter intake, balanced ration, roughage-to-concentrate ratio, water, minerals and cheap local feed resources.
Core rules
- Dry matter intake: about 2.5–3 kg DM per 100 kg body weight; a 400 kg cow eats 10–12 kg DM daily.
- Roughage first: 60–70% of DM from green fodder, hay or straw; concentrate fills the gap for milk production.
- Concentrate rule of thumb: maintenance plus about 1 kg concentrate mixture for every 2.5 litres of milk above the first 5 litres for crossbred cows; buffaloes need slightly more per litre.
- Protein and energy: check DCP and TDN against ICAR or BIS tables; a milch animal ration is commonly 16–18% crude protein.
- Water: 60–100 litres a day, roughly 3–4 litres per litre of milk; clean and available after milking.
- Minerals and salt: 50–100 g mineral mixture and 30–50 g common salt daily; deficiency shows as poor fertility, stiffness and low yield.
- Transition and calves: change feed over 7–10 days; give calves colostrum within the first hour, then whole milk and calf starter.
Cheap local options
Urea-treated straw (4 kg urea in 100 kg straw, sealed for 3 weeks) raises crude protein; silage and hay bridge the lean season; azolla and tree leaves add protein.
Worked example
A 400 kg crossbred cow gives 12 litres. DM need = 12 kg. Roughage at 8 kg DM (green fodder plus straw) leaves 4 kg DM from concentrate. Milk above 5 litres = 7 litres, so concentrate is about 3 kg for milk plus 1 kg maintenance, roughly 4 kg. Add 75 g mineral mixture and free water. Reasoning: roughage covers maintenance, concentrate is costed against marginal milk.
Traps
- Pushing concentrate without roughage, causing acidosis and off-feed.
- Sudden change of green fodder.
- Forgetting minerals and salt.
- Feeding urea to calves, or giving urea without gradual adaptation.