Animal Production and Livestock Husbandry
This domain tests your knowledge of how farm animals digest feed, how rations and breeding are managed, and how housing, health and records keep a livestock enterprise productive.
Digestive systems
Ruminants (cattle, sheep, goats) have four stomach compartments - rumen, reticulum, omasum and abomasum - and rumen microbes digest cellulose, so they use roughage. Non-ruminants (pigs, poultry) have a simple stomach and need concentrates; they cannot use much fibre. Horses and rabbits use hind-gut fermentation.
Feeding, breeding and health
Distinguish a maintenance ration (keeps the animal alive, no gain) from a production ration (growth, milk, eggs, pregnancy). Rations supply energy, protein, minerals, vitamins and water. Breeding relies on detecting oestrus and serving at the right time; know the oestrus cycle length and gestation - about 283 days for cattle, 114 for pigs and 147 for sheep, with 21-day incubation for hens. Health management means vaccination, quarantine, parasite control (ticks, worms), clean water and biosecurity.
Worked example
A pen of broilers consumes 180 kg of feed and gains 90 kg liveweight. Feed conversion ratio = feed eaten ÷ liveweight gain = 180 ÷ 90 = 2.0. A second pen achieves 2.3. The first flock is more efficient because a lower FCR means less feed per kilogram of meat; with feed being the largest cost, that is the more profitable flock, all else equal.
Traps that cost marks
Lower FCR is better - do not treat it like a growth figure. Feed efficiency is the reciprocal (gain ÷ feed). Roughage suits ruminants, not poultry. Do not describe a maintenance ration as 'poor feed'. Confusing oestrus (heat) with gestation is a common error.