Variety traits and selection
A breed is a group of animals of one kind with shared body and production traits. Milk breeds are lean with a big udder. Meat breeds are broad and muscular and put on weight fast. Hardy local breeds give less milk but bear heat, ticks and poor feed. Choose by your goal, your climate and your feed supply. A farm with little green fodder may do better with a hardy breed than a high-yield foreign breed.
Livestock improvement
Improvement means making the next generation better than the last. Two ways: selection (keep calves of the best mothers and fathers, using records of milk or weight) gives steady, small gains each generation. Crossbreeding (mating two breeds) gives a big jump in the first generation, called hybrid vigour, but later generations need careful planning. Keep records of each animal: birth date, parents, milk, weight and illnesses.
Breeding plans and management
A cow is useful only when she gives milk, so she must calve regularly. A good plan: the cow comes on heat about every 21 days; watch for it; breed her in month 3 after calving; pregnancy lasts about 9 months (cow); give a 2-month dry period before the next calving so she can rest; target a calving interval of about 12 months. Use artificial insemination (AI) to use semen from the best bulls safely. Record heat dates, breeding date and expected calving date.
Rearing plans and management
A rearing plan sets how animals are raised from birth to sale: calf stage (give colostrum, the first milk, within hours), heifer or growing stage, adult producer stage and dry stage. For each stage decide feed, housing, space per animal, weighing dates and health checks. Daily management includes feeding at fixed times, clean water all day, cleaning the shed, checking each animal and writing records. A target such as 250 kg at 18 months tells you whether the plan works.
Livestock and feed
Feed is the biggest cost on a livestock farm. A ration mixes roughage (green fodder, silage, dry straw) with concentrate (grain, oilcake, bran) and minerals with clean water. Ruminants like cows need plenty of roughage for a healthy stomach. A little concentrate raises milk, but too much upsets the stomach (acidosis), costs more and lowers milk. Give more feed to high-yielding and pregnant cows. In this lesson's model about 15 to 40 percent concentrate gives a balanced ration.
Livestock diseases and prevention
Prevention is cheaper than cure. Four tools: vaccination on schedule (for example for foot-and-mouth disease), hygiene (clean shed, clean water and feed, clean milking), quarantine (keep new or sick animals apart for two to three weeks) and deworming and tick control. Signs of illness: not eating, dull eyes, fever, less milk, limping. Call a veterinary doctor early. Never give medicines without advice, and respect the milk withdrawal period after treatment.
Marketing and evaluating livestock products
Livestock products include milk, eggs, meat, wool and manure. Product quality is checked: milk by fat and SNF (solids-not-fat), cleanliness and temperature; eggs by size and shell; meat by weight and grade. Chill milk quickly and deliver to a dairy cooperative or direct to customers. Evaluate the farm with simple numbers: yield per animal per day, feed cost per litre, calving interval, death rate, and net income per month. Compare them with your plan and improve the weakest number first.
Using barns, machinery and facilities
A good barn gives shade, airflow, a dry non-slip floor, clean water points, feed troughs and a drain for dung. Plan about 3.5 to 4 square metres of covered space per adult cow and plenty of open space. Machines include chaff cutters, milking machines, bulk milk coolers and dung handling systems (biogas). A milking machine saves time on a bigger herd and keeps the milk cleaner, but it must be cleaned and checked every day. Keep guards on blades and keep children away.
Try it
Visit a dairy or poultry farm, or look at a farm video, and list: the breed, what the animals eat, how the shed is kept clean, and what records are written. Then draw a simple 12-month calendar for one cow with heat, breeding, dry period and calving marked. Compare with the breeding timeline in the 3D.
Key formulas and definitions
- Calving interval (months) = months from one calving to the next; target about 12
- Feed cost per litre = daily feed cost / daily milk yield
- Milking time = number of cows x minutes per cow
- Selection gain: milk = start yield x (1.08) to the power of generations (in this model)
- Death rate (%) = deaths / animals x 100
Worked examples
1. A cow calves in January and is bred in April. How many months after calving is she bred? When is she likely to calve again (9-month pregnancy)?
January to April is 3 months. Calving is about 9 months after April, so about January next year (12 months after the last calving).
2. A herd gives 8 litres per cow per day at start. With selection at 8% gain per generation, what is the yield after 3 generations?
8 x 1.08 x 1.08 x 1.08 = 8 x 1.2597 = about 10.1 litres per day.
3. A ration has 20% concentrate and gives 10 L milk. The feed costs 160 per day. What is the feed cost per litre?
160 / 10 = 16 per litre.
4. Compare: 40% concentrate gives 14 L at 220 per day; 60% gives 9 L at 280 per day. Which is cheaper per litre?
40%: 220 / 14 = 15.7. 60%: 280 / 9 = 31.1. The 40% ration is cheaper per litre and gives more milk.
5. A farm has 12 cows. Hand milking takes 6 minutes per cow. A machine takes about 2 minutes per cow. How much time does each take?
Hand: 12 x 6 = 72 minutes = 1.2 hours. Machine: 12 x 2 = 24 minutes = 0.4 hour. The machine saves 48 minutes.
6. In a herd of 100 cows, 3 die in a year. What is the death rate? After vaccination only 1 dies. By how many percentage points did it fall?
First: 3 / 100 x 100 = 3%. After: 1%. Fall = 2 percentage points.
Common mistakes
- Choosing the highest-yield foreign breed without enough green fodder or shade.
- Feeding lots of grain to get more milk. Too much grain upsets the stomach and raises cost.
- Missing the heat and breeding late, so the calving interval becomes 15 or more months.
- Treating animals only after they fall sick, instead of vaccinating and keeping the shed clean.