90-Day Lamb Fattening Plan: Phases, Rations and Weighing

A 90-day lamb fattening plan works in four steps: receive and check the lambs, adapt them slowly to the ration over about two weeks, feed a balanced growth ration with more concentrate, then finish them and sell at the target weight. Weigh at the start and every two to four weeks, follow your vet's health plan, and track feed per group to know your real cost.

Fattening is where many farms make or lose their margin. Lambs bought or weaned at the right weight can add value quickly, but only if they stay healthy, eat well and leave the barn on time. A written plan, even a simple one, keeps everybody on the same page and makes the results measurable.

Before day 1: choose and receive the lambs

Good fattening starts with the animals you put in:

• Choose healthy, active lambs with bright eyes, clean noses and no lameness or diarrhoea. Avoid animals that look stunted for their age.
• Prefer similar weights and ages in one group. A mixed group eats unevenly and is harder to manage.
• Isolate new arrivals. Lambs bought from markets or other farms should be kept apart and observed before joining your other animals.
• Health plan with your vet. Vaccination against clostridial diseases such as enterotoxemia, parasite control and any other treatments should follow your vet's advice and the local schedule.
• Record each lamb: number and tag colour, sex, breed, source and starting weight. Without a starting weight, you cannot measure anything.

On arrival, give clean water and good hay first. Stressed, hungry lambs that gorge on concentrate are at high risk of digestive problems.

The four phases at a glance

The table below shows an illustrative plan for lambs starting at about 20 to 25 kg. Quantities are examples to adapt with a nutritionist to your breed, feed quality and climate.

Daily gain depends heavily on breed, sex, starting weight and ration. Many farms see gains of roughly 150 to 300 g per day in good conditions, but your own weighings are the only reliable figure for your flock.

Phase by phase: what to do

Adaptation (days 1 to 14)

The rumen needs time to adjust to grain. Increase the concentrate in small steps every two or three days, split into at least two meals, and keep hay always available. Check dung and appetite daily. If lambs go off feed, have loose dung or look bloated, slow down and call your vet.

Growth (days 15 to 60)

This is the most efficient part of the period. Keep the ration stable, give enough trough space so every lamb can eat at once, and make sure water is clean and plentiful. Weigh at about day 30: lambs that are clearly behind should be checked for health problems and, if needed, separated.

Finishing (days 61 to 90)

As lambs get heavier, they usually need more feed for each extra kilo. Weigh again around day 60 and day 90, and look at condition by hand along the back and ribs. When a group reaches the weight and finish your market wants, plan the sale. Keeping them longer "for a better price" often adds more feed cost than value.

Health and welfare during fattening

Fattening lambs eat a rich diet in close quarters, so a few risks need constant attention:

• Digestive problems from sudden ration changes or overeating. Gradual changes and regular feeding times help.
• Respiratory problems in dusty or poorly ventilated barns, especially with large temperature swings.
• Urinary stones in male lambs on high-grain diets. Plenty of water, enough roughage and a balanced mineral supply reduce the risk; discuss prevention with your vet.
• Heat stress in summer: provide shade, airflow and cool water, and feed more in the cooler hours.

Any sudden death, lameness or group of animals off feed is a reason to call the vet quickly, not to wait.

Running the plan with records

A plan only helps if it is followed and measured. In practice:

1. Put all lambs of the batch in one group, with a start date.
2. Record each lamb's starting weight, then weigh on about days 30, 60 and 90.
3. Record what the group eats every day and every feed purchase.
4. Record vaccinations and treatments with dates.
5. At the end, compare total feed with total gain and with the sale price.

In Throf, you can place the lambs in the fattening stage and in one group (pen), record meals that are deducted from your feed stock, enter weights per animal and log vaccinations and treatments with reminders. With feed and weights in the same place, you can calculate the feed conversion ratio of the batch and its cost per head, then compare it with your next batch. For the ration itself, our guide to barley and alfalfa rations explains how the two ingredients work together.

The short version

Start with healthy, uniform lambs and a starting weight. Spend two weeks on a careful transition, then feed a stable, balanced growth ration with enough roughage and water. Weigh regularly, follow your vet's plan, and sell when the group reaches target weight. Write it down, measure it, and each batch will teach you how to make the next one more profitable.