Why Are My Broilers Not Growing?

Posted by: Samuel Ezenwankwo 2 years, 2 months ago/ (3 comments)

The reasons why your broilers are not growing could involve more than one reason. The two basic causes of stunted or slow growth in broilers are poor welfare, which may result in a disease outbreak, feed poisoning, accident, high temperature, etc, and genetic make- up of the broiler chicken, which sometimes may not be corrected easily. All these factors are capable of causing stunted growth in your broilers. 

However, every broiler farmer expects to attain uniformity in growth and weight in his or her flock. The farm becomes depressed when these expectations are not met. Which in turn will hurt his return of investment, especially when the number of runts increases- runts are animals, especially birds smaller than their mates, caused by poor health or poor nutrition, but could grow to full size as his mate if given special care.

Also read:  How to Stop watery whitish, greenish, brownish-yellow and blood stain in your Chickens poops for full Recovery

Fortunately, this condition could be prevented or minimized if you follow my tips and suggestions. Moreover, I have researched 10 reasons why your broilers are not growing.

1. Genetic makeup of the Broiler Chicken

Broilers are known for their fast growth rate, and this trait is embedded in their gene. However, some events may occur during development that may affect this particular gene from developing properly, and as such the resulting broiler chick may not attain its full genetic potentials, which includes a fast growth rate. And in most cases this condition is untreatable, e.g Runting and stunting syndrome

Runting and stunting syndrome (RSS) is a condition in which a number of the birds in a flock are considerably smaller owing to delayed growth, and RSS chickens are easily observed in sex-linked dwarf (SLD) chickens. It is known that the SLD chickens are caused by the mutation of growth hormone receptor (GHR) gene and characterized by shorter shanks, and lower body weight

Also read: 10 ways to sell and market your broiler chickens fast that are proven to work

What to do: 

Ensure to get your chicks from a reputable hatchery that knows what they are doing. The hatchery should have a good track record for producing high-quality chicks. If you do 

the hatching yourself, you should ensure your breeders is well selected and given the right medication that will help them to produce healthy broiler chicks.

2.  Getting your Chicks from a Substandard Hatchery

This is similar to the first point, and is one of the common mistakes poultry farmers make. Apart from genetic defects, they are other growth problems that could result from poor hatcheries; this includes diseases, deformities like paralysis, or lameness due to high temperature in the incubator. Some hatcheries are not disciplined enough to complete the necessary medication on their breeder stock, which will result in poor growth in the offsprings.

What to do:

 Same as point one above.

3.  Overcrowding: 

Overcrowding is a hub for many vices and diseases in poultry, which can affect the growth of your birds negatively. For instance, overcrowding can lead to cannibalism where birds feed (peck) on each other due to limited space and feeder. The result is that the smaller birds will sustain injuries and will be scared to eat, and as such will remain starved most of the time.

And again, overcrowding increases the litter density and invariably increases the population of disease-causing organisms in the pen. This can also cause poor ventilation, heat stress which in turn increases feed conversion ration, and mortality. All these put together will drastically reduce the growth rate of your broiler chickens.

What to do:

Provide enough feeders and drinkers for your broiler chickens. Make sure there is enough space in a well-ventilated pen. The standard floor space requirement for broiler chicks is 0.09sqm. For 100 chicks is 9sqm for the first week alone. The floor space should be increased by 0.09sqm weekly till week 4.

Also read: 40 Facts about chickens that will blow your mind !

4.Poor Brooding method

Brooding, and the first 7 days are critical stages in the life of a chick. The method of brooding broiler in the first week will determine how well your broiler chicks will grow. This is because within the first 7 days the chick spends 80% of its energy on growth while 20 % on maintenance, the reverse is the case as the chick ages.

Therefore, you must maximize these first days for optimal growth. Any mistake made in terms of feed, vaccination, and temperature will not only affect its growth but also will threaten its life.

Day old chicks in the brooder

What to do

In brooding broiler, you must maintain a specific range of temperature for optimal growth. Any deviation from this temperature range will hurt the life of the chick. Any temperature higher than 33 and 35 °C will induce hyperthermia,  while a lower temperature will induce hypothermia.

Also, make sure their medication and vaccination are up to date. 

Also read:Blog post: 8 Best poultry feeds in Nigeria with their prices for optimal birds' growth

5. Malabsorption Syndrome in Chickens (MAS) Or Runting Stunting Syndrome (RSS)

MAS and RSS are a severe health condition that adversely affect the growth performance of your broiler chickens.Signs of MAS and RSS are mainly underweight and smallish stature. RSS is common among “meat-type” chicken breeds or broilers and is associated with a rotavirus infection. 

Viruses invade the intestinal mucosal cell at the edges of the intestinal villi which aid digestion. The replication of the virus causes the disintegration of a cell by rupture of the cell wall or membrane of the bird’s cells by impairing absorption.

Clinical signs include

  • Stunted or poor growth

  • Underweight




  • Smaller body size



  • Pale skin pigmentation



  • Morbidity

  • Chick’s beak and legs appear as a paler color than normal birds



  • Poor feathering

  • Chicks may have few feathering and usually curled wingtips, and leg weakness


  • Chick may have rickets, with weak or broken legs.

Broiler chicks suffering from RSS

What to do 

  • Practice good brooding method



  • Practise good litter management



  • Practise good biosecurity measures

  • Good poultry house management


  • Give complete vaccination

6. Lack of Adequate Number of Feeders and Drinkers

If you want to prevent or minimize the number of runt in your flock, provide enough feeders and drinkers. The feeders should be closer to the drinkers, and easily accessible. But not so close to causing feed spoilage. Randomly fill the feeders with little feed to avoid rushing and stampeding.

The runts or small size birds should be separated and be fed separately. They should be given special feeding and care to help them catch up with the expected weight with the rest of the  

Also read: 8 Beginner's guide in poultry farming in Nigeria you must follow, If you want to be successful

7. Lack of Quality Feed:

The quality of feed you give to your broiler chickens will determine their growth performance. A feed formulated with low-quality ingredients will give a poor result. For example, feed formulated with spoilt corn grains and a moldy fish meal will cause food poisoning(mycotoxins), will reduce the nutritional composition of the feed.

 Another adverse effect of using such feed is that essential nutrients would have been lost; hence, they are not available for the chickens to use and causing severe undernourishment to the broiler chickens that eat it.

Quality feed in different texture; mash, crumble and pellet feed texture

Some dubious feed millers will purposely prepare the wrong feed for your broiler. For instance, when the miller runs out of raw material for the finisher, he or she will purposely bag starter feed inside a finisher’s bag and you will continue to feed your birds expecting a change in growth that may never come.

Another aspect is when there is a hike in feed ingredients or raw material, the milers will result in a low-quality ingredient. And when you feed it to your broiler chickens they will never attain the expected weight because the nutritional composition is inadequate.

What to do

Make sure your miller uses high-quality feed ingredients. Store your feed in a cool dry place free from moisture. If you are using silos, ensure it is well cleaned and free from heat patches that could trigger spoilage.

Don’t store feed that will not finish with 3 to 4 weeks at maximum, they could become moldy and could be poisonous to your broiler chickens.

Get your feed from a trustworthy miller that will give you the right feed and will be sincere enough to tell you the feed batch and its expiring date.

8. Present of Parasites 

A Parasite is an organism that lives in or another organism (referred to as the host) and gains an advantage at the expense of that organism (host). A parasite can be either an internal or external parasite.  

Examples of Poultry internal parasites that affected poultry are worms:e.g roundworms, cecal worms, tapeworms, and protozoa:e.g coccidian (responsible for coccidiosis), cryptosporidia, and histomonads. While major external parasites are mite and lice. 

These parasites will not only cause poor growth in your broiler chickens but will also reduce their immune system which will make them more susceptible to diseases or worsen a current disease condition.

What to do:

 For worms, visit a veterinarian for a proper prescription. In the absence of a vet, you can buy a dewormer that is effective against that particular worm. Keep your pen clean to prevent your bird from picking these worms from infested poops. Also control intermediate host (vectors) like a housefly, beetles termites, etc

For lice and mite, regularly check birds for signs of mite and lice and check common hiding places such as under perches and in cracks. Keep pen clean and where possible allow your birds to dust bath. Also, keep away rodents and local chickens from your pen, they are a major carrier of mite and lice.

The parasite causes distress in chickens, and when birds are in distress they focus all their energy (include growth energy) on survival.

Also read: 8 Things I wish I’d known About Poultry farming. Don't neglect No 7

9.  Disease

The presence of diseases in your broiler flock is undoubtedly one of the major why your broilers are not growing. A sick bird will not feed and drink and a bird who does not feed will lack energy for normal body functions which include growth. The immunity will be reduced and the bird becomes susceptible to other diseases that may lead to death.

What to do:

Vaccinate your birds against major diseases like Newcastle disease, Marek disease, Infectious Bursal Disease (IBD), and other diseases that may be prevalent in your region. Ensure you use a standard vaccination schedule.

Maintain high biosecurity on your farm. Keep your farm environment clean and free from stagnant water. Make use of a foot bath and control the movement of farm visitors.

In conclusion, ensure you follow these guides whenever your broiler is not growing. However, they are r reasons that may cause your birds not to grow, but the ones mentioned here are among the major causes of stunted or poor growth in broiler chickens. 

Please comment and Share!






Christy 1 year, 10 months ago

Thank you very much for this post. God bless you.

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Ibrahim Isiyaku 1 year, 7 months ago

May broilers are growing slowly and they're 4weeks 2days what am I going to give them some has leg problem

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Comment awaiting approval 8 months, 3 weeks ago

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