Animal Husbandry and Dairy: Livestock, Poultry and Milk Processing
This domain covers rearing of cattle, buffalo and poultry and the first stages of dairy processing. Questions range from breed identification and reproduction cycles to pasteurization temperatures and milk standardization.
Livestock
Indigenous cattle (Gir, Sahiwal, Red Sindhi) tolerate heat and ticks; exotic breeds (Jersey, Holstein Friesian) yield more milk but demand better feed and management. Murrah is a leading buffalo breed. The oestrus cycle in cattle is about 21 days and gestation about 280-285 days, which is why a missed heat delays calving and the next lactation. A balanced ration combines roughage, concentrate, minerals and clean water.
Poultry
Layers begin laying around 18-20 weeks; broilers are marketed at about 6-7 weeks. Chicken eggs hatch in 21 days (duck and turkey about 28). Brooding supplies heat to chicks. Vaccination and biosecurity (Ranikhet, fowl pox, IBD) prevent losses far more cheaply than treatment.
Dairy processing
Pasteurization (LTLT 63 C for 30 minutes, HTST 72 C for 15 seconds) destroys pathogens without sterilizing milk. Cream is separated by gravity or centrifuge; butter comes from churning cream; ghee from clarifying butter; khoa from continuous stirring and evaporation; curd from controlled lactic fermentation.
Worked example
Standardize milk to 4.5% fat using whole milk at 6.0% fat and skim milk at 0.5% fat. Pearson square: whole milk parts = 4.5 - 0.5 = 4.0; skim parts = 6.0 - 4.5 = 1.5, so the ratio is 4.0 : 1.5, i.e. 8 : 3. For 110 kg, use 80 kg whole milk and 30 kg skim milk; check: (80 x 6.0 + 30 x 0.5) / 110 = 4.5% fat.
Traps that cost marks
- Saying pasteurization sterilizes milk; it does not.
- Confusing layer and broiler production targets.
- Forgetting colostrum for newborn calves.
- Mixing up the 21-day incubation period of chicken with the 21-day oestrus cycle of cattle.