Animal Production and Husbandry
This domain covers feeding, breeding, handling and welfare of Namibian livestock, mainly cattle, sheep and goats. Exam questions ask you to calculate rations or stocking rates and to justify management decisions.
Feeding rules
- Dry matter (DM) intake for ruminants is about 2.5-3% of body weight per day.
- Crude protein needs are roughly 7-8% for maintenance and 12-16% for growth, pregnancy and lactation; energy is usually the first limiting factor on dry Namibian rangeland.
- Always compare feeds on a dry matter basis. Hay at 90% DM contains 0.9 kg DM per kg fresh feed.
- Supplement protein, phosphorus and salt in the dry season; urea is safe only for ruminants and must be introduced gradually.
Stocking and breeding
- One livestock unit (LSU) is about 450 kg live weight. Roughly 6-8 sheep or goats equal 1 LSU.
- Carrying capacity falls as rainfall falls: about 4-5 ha/LSU at 600 mm, 8-10 ha at 450 mm and 25-30 ha at 250 mm.
- Gestation is about 283 days in cattle, 150 days in sheep and 150 days in goats. Time breeding so that lactation and weaning coincide with the best grazing.
- Condition-score animals (1-5 scale) to judge whether supplementary feeding is needed.
Worked example
A farmer has 40 cows averaging 450 kg. Daily DM need is 2.5% x 450 kg = 11.25 kg DM per cow, so 450 kg DM for the herd. If hay is 90% DM, fresh hay needed is 450/0.90 = 500 kg/day. With 10% feeding waste, supply about 550 kg/day. The reasoning converts body weight to DM, herd size to total DM, then DM to fresh feed and allows for wastage.
Traps
- Mixing fresh weight and dry matter.
- Treating LSU as a head count rather than a weight-based unit.
- Feeding urea to pigs or poultry, which can be fatal.
- Breeding all year without matching feed supply to lactation.