Monitoring broiler growth is one of the simplest ways to determine whether a flock is developing as expected.

Farmers often look at the size of birds and assume that growth is satisfactory. However, visual inspection alone can be misleading. Regular weighing provides objective information that can be compared with the farm's target growth programme.

There is no single target weight that applies to every broiler flock. Breed, sex, feed programme, management, environment, and market requirements all influence growth.

Why Monitor Broiler Weight?

Weight monitoring helps farmers answer important questions:

  • Are birds growing as expected?
  • Is the flock reasonably uniform?
  • Is feed producing the expected growth?
  • Are birds ready for market?
  • Should the production cycle continue?
  • Is there a possible management problem?

What Is a Target Weight?

A target weight is an expected weight for birds at a particular age under a specified production programme.

Targets are not guarantees. A farmer may create a programme specifying expected weights at Day 1, Day 7, Day 14, Day 21, Day 28, Day 35, and Day 42.

Example Growth Programme

Age Target Weight
Day 1 Record hatchery/chick weight
Day 7 Farm target
Day 14 Farm target
Day 21 Farm target
Day 28 Farm target
Day 35 Farm target
Day 42 Farm target

The farmer should enter targets appropriate for the specific strain and production system being used.

How to Weigh Birds

Use a reliable weighing scale. A common approach is to weigh a representative sample rather than every bird.

  1. Select birds from different areas of the house.
  2. Avoid selecting only the largest or smallest birds.
  3. Use the same weighing scale.
  4. Record the number of birds weighed.
  5. Calculate the average weight.
  6. Compare the result with the target.

Calculating Average Weight

Suppose five birds weigh 1.80 kg, 1.95 kg, 1.75 kg, 1.90 kg, and 1.85 kg.

Total weight:

1.80 + 1.95 + 1.75 + 1.90 + 1.85 = 9.25 kg

Average:

9.25 ÷ 5 = 1.85 kg

The recorded average weight is therefore 1.85 kg.

Understanding Growth Trends

One measurement is less useful than a series of measurements.

Week Average Weight
Week 1 0.18 kg
Week 2 0.45 kg
Week 3 0.80 kg
Week 4 1.25 kg
Week 5 1.70 kg
Week 6 2.10 kg

The figures above are an example of a growth record rather than a universal breed standard.

Causes of Poor Growth

Feed Problems

  • Poor-quality feed
  • Incorrect feed formulation
  • Feed shortage
  • Feed wastage
  • Poor storage

Water Problems

  • Empty drinkers
  • Blocked drinkers
  • Poor water quality
  • Insufficient water access

Environmental Problems

  • Excessive heat
  • Excessive cold
  • Poor ventilation
  • Excessive stocking density
  • Wet litter

Health Problems

Disease and other health issues can reduce feed intake and growth. When disease is suspected, seek appropriate veterinary or poultry-health advice.

Flock Uniformity

Average weight alone does not tell the entire story.

Two flocks could have the same average weight while having very different levels of uniformity. A flock in which most birds are close to the average is generally more uniform than a flock containing very large differences between individual birds.

Target Weight vs Actual Weight

A target should be used as a management reference, not as an absolute guarantee.

If actual weight is below target:

  1. Confirm the weighing method.
  2. Review feed availability.
  3. Check water.
  4. Review environmental conditions.
  5. Check mortality.
  6. Review health records.
  7. Investigate feed quality.
  8. Examine stocking density.

Do not immediately assume that simply providing more feed will solve the problem.

Growth and Feed Efficiency

Growth should be evaluated alongside feed consumption.

For example:

Batch A Batch B
Feed consumed 180 kg 220 kg
Weight gain 90 kg 100 kg
FCR 2.0 2.2

Batch B produced more total weight, but it used more feed for each unit of weight gain. The economic result depends on feed price, selling price, mortality, and other costs.

Growth and Mortality

Mortality also affects the economics of growth. If a farmer starts with 100 birds but sells 90, final revenue comes from 90 birds.

Growth monitoring and mortality monitoring should therefore be considered together.

Using a Growth Chart

A growth chart can display target and actual weight. A visual chart makes it easier to identify when actual performance begins to diverge from the target.

This can be particularly useful for farms managing multiple batches.

When Should Broilers Be Sold?

There is no universal market day for every farm.

The best selling point depends on:

  • Target weight
  • Feed price
  • Market price
  • Bird health
  • Customer requirements
  • Housing capacity
  • Cost of keeping birds longer

A farmer should calculate whether additional days of feeding are likely to produce enough additional revenue to justify the additional costs.

Record Growth Consistently

Date Bird Age Sample Size Average Weight Target
Date Day 7 10 Actual Target
Date Day 14 10 Actual Target
Date Day 21 10 Actual Target
Date Day 28 10 Actual Target
Date Day 35 10 Actual Target
Date Day 42 10 Actual Target

Final Thoughts

Growth monitoring gives farmers a practical way to understand flock performance.

Rather than relying on appearance alone, weigh representative birds regularly, compare actual results with realistic targets, and investigate unexpected changes.

When weight records are combined with feed, mortality, and expense records, the farmer gets a much clearer picture of the biological and financial performance of the flock.