BGCSE Animal Production 1255 cheat sheet

Monogastric digestion: stomach (HCl, pepsin) → duodenum (bile, pancreatic enzymes) → jejunum/ileum absorption → large intestine water resorption and fermentation.

Ruminant stomach order: reticulum → rumen → omasum → abomasum; rumen pH 6.0–7.0 supports cellulolytic microbes, below 5.5 causes acidosis.

Eructation removes fermentation gases (CO2, CH4); failure to eructate causes bloat, a life-threatening condition.

Mammary gland milk let-down is triggered by oxytocin released on teat stimulation; adrenaline inhibits let-down.

Body temperature regulation: panting and sweating dissipate heat; poultry pant and hold wings away from body to lose heat.

Respiratory rate and pulse are species-specific baselines; deviations indicate fever, pain, stress, or respiratory disease.

Rumen fermentation yields volatile fatty acids (acetate, propionate, butyrate) that supply most ruminant energy.

Kidney function maintains water and electrolyte balance; urine colour and volume are practical hydration indicators.

Nutrient classes: water, carbohydrates, fats, proteins, minerals, vitamins; water is the most critical and cheapest nutrient.

Crude protein (CP) = nitrogen × 6.25; it estimates protein content but not amino acid quality.

Total digestible nutrients (TDN) express energy value; higher TDN means more usable energy per unit feed.

Ration must meet maintenance first, then production (growth, milk, pregnancy, work); deficits reduce output.

Roughage-to-concentrate ratio: high roughage for maintenance, higher concentrate for high milk yield or finishing.

Calcium-to-phosphorus ratio in a ration should be about 1.5:1 to 2:1; imbalance impairs bone growth.

Feed storage: keep dry (<12% moisture), cool, ventilated, and off the floor to prevent mould and aflatoxin.

Water intake is roughly 2–4 litres per litre of milk in dairy cattle; restricted water cuts feed intake and yield.

Feed conversion ratio (FCR) = feed consumed ÷ weight gain or output; lower FCR means more efficient production.

Disease signs to record: appetite loss, temperature change, discharge, lameness, diarrhoea, sudden drop in production.

Infectious vs non-infectious: infectious agents (bacteria, viruses, fungi) spread between animals; non-infectious causes include nutrition, injury, toxins.

External parasites: ticks, mites, lice, fleas; internal parasites: roundworms, tapeworms, flukes.

Tick control reduces tick-borne disease (e.g., anaplasmosis, heartwater); rotate acaricides to slow resistance.

Vaccination builds immunity before exposure; a cold chain must be maintained or vaccine potency is lost.

Withdrawal period is the time after drug administration before milk, meat, or eggs can be sold for human consumption.

Quarantine new or sick animals for at least 21–30 days before mixing with the herd.

Zoonoses (e.g., brucellosis, anthrax, rabies) transmit from animals to humans; handle aborting animals with gloves.

Genotype = genetic makeup; phenotype = genotype + environment; selection acts on phenotype but changes genotype frequency.

Heritability (h²) is the proportion of phenotypic variation due to additive genetic effects; high h² traits respond fast to selection.

Selection differential is the difference between selected parents' mean and herd mean; response = h² × selection differential.

Inbreeding raises homozygosity, exposing recessive defects and reducing fertility; avoid mating close relatives.

Crossbreeding exploits heterosis (hybrid vigour); first-cross offspring often outperform parental breeds.

Breeding value (EBV) estimates genetic merit; records of relatives and own performance improve accuracy.

Sex-limited traits (milk yield, egg number) require progeny or sibling testing for accurate selection.

Linebreeding and outcrossing are tools to manage genetic diversity within a herd or flock.

Extensive system: low stocking density, natural grazing, low inputs, lower output per hectare.

Intensive system: high stocking density, controlled feed and housing, high output but higher disease and stress risk.

Stocking rate is animals per unit area; overstocking degrades pasture and increases parasite load.

Rotational grazing rests paddocks, allowing regrowth and reducing internal parasite exposure.

Identification (ear tag, brand, tattoo) links animals to records; accurate ID is essential for traceability.

Castration, dehorning, and hoof trimming are routine management tasks; timing depends on species and age.

Culling removes unproductive or diseased animals; selection criteria include fertility, health, and production records.

Record key dates: mating, expected calving/farrowing, weaning, vaccination, deworming, and market weight.

Incubation: chicken 21 days, duck 28 days, turkey 28 days; temperature about 37.5°C, humidity 55–65%.

Candling around day 7–10 identifies infertile eggs and dead embryos; remove clear eggs to prevent spoilage.

Brooding temperature: start around 32–35°C and reduce about 3°C weekly; chicks huddle when cold, pant when hot.

Layer diets require calcium for shell formation; shell quality declines with age, heat stress, and calcium deficiency.

Broiler production targets high feed conversion and rapid growth; FCR around 1.6–2.0 is typical for good flocks.

Ventilation removes ammonia and moisture; high litter moisture causes coccidiosis and footpad problems.

Lighting programme controls sexual maturity and egg production; pullets need controlled day length before lay.

Biosecurity essentials: all-in/all-out, footbaths, restricted visitors, rodent control, and clean water lines.

Gestation length: goat about 150 days, sheep about 147 days, pig about 114 days (3 months, 3 weeks, 3 days).

Sheep and goats are small ruminants with a four-compartment stomach; they require roughage for rumen health.

Pig is monogastric; diet needs balanced amino acids, especially lysine, and cannot use roughage efficiently.

Farrowing management: provide a warm creep area and farrowing rails to reduce piglet crushing.

Weaning ages: lambs/kids around 8–12 weeks; piglets around 21–28 days in intensive systems.

Swine heat detection: sows show standing heat; mating or AI is timed about 12–24 hours after standing onset.

Shearing, foot trimming, and drenching are routine small-ruminant tasks; record dates for parasite control.

Iron injection for piglets prevents anaemia because sow milk is low in iron.

Flooring must be dry, non-slip, and easy to clean; wet floors increase mastitis, foot rot, and ammonia.

Space allowance per animal affects growth, feed intake, and aggression; crowding reduces performance.

Ventilation design: inlet high, outlet low or ridge outlet, to remove warm moist air without draughts on animals.

Feed trough space must allow all animals to eat at once or competition reduces intake of weaker animals.

Water troughs should be cleaned regularly and placed to avoid contamination by manure.

Milking equipment: clean and sanitise before and after use; check teat cup liners and vacuum level.

Handling facilities: crush, race, and head bail reduce injury to animals and handlers during treatment.

Poultry house: litter depth, nest boxes, perches, and feeders must match bird type (layer, broiler, breeder).

Gross margin = gross output (sales + inventory change) − variable costs; fixed costs are excluded.

Profit = total revenue − total costs (variable + fixed); enterprise budgets compare options.

Break-even output = fixed costs ÷ (unit price − variable cost per unit).

Key records: breeding, health/vaccination, feed consumption, production (milk, eggs, weight), and financial ledgers.

Stock inventory records track births, deaths, purchases, sales, and transfers; reconcile with physical counts.

Cost of production per litre of milk or per kg of meat guides pricing decisions and culling.

Marketing channels: farm gate, auction, cooperative, processor contract; each has different price and risk.

Value addition (processing, packaging, grading) can raise income but adds capital and compliance costs.

Five freedoms: from hunger/thirst, discomfort, pain/injury/disease, fear/distress, and freedom to express normal behaviour.

Biosecurity layers: perimeter control, visitor and vehicle protocols, all-in/all-out, and pest control.

Manure management: composting or lagoon storage reduces pathogens; spread only at rates matching crop needs.

Ammonia and odour control through ventilation, dry litter, and frequent manure removal protects animals and neighbours.

Water source protection prevents contamination of streams and groundwater by runoff from pens.

Dead animal disposal: incineration, burial, or approved rendering; never leave carcasses accessible to scavengers.

Antimicrobial stewardship: use only when indicated, follow dose and withdrawal, and record all treatments.

Stress reduction during handling: use flight zone, avoid yelling and hitting, and move animals calmly.