Lenny Gitonga, a poultry farmer at his farm at Nkoben village in Narok South subcounty. [Robert Kiplagat, Standard]

Dear Dr Messo

My layer chickens are now 16 weeks. Recently, I noticed that they make a lot of noise during the day. I thought there might be a predator in the unit, so I built roosting perches for them. This did not solve the problem. During the day, they are restless and fly all over, is that normal? It’s my first-time rearing layer flock. Raham Abbas, Mombasa.

Dear Raham

Commercial chicken farming requires a high level of expertise, understanding, and commitment to be successful.

While it’s important to always emphasise the need for excellent flock stockmanship, something that comes with experience and aptitude, adopting the correct housing techniques and equipment will set a firm foundation for success.

Going through your social media conversation on this matter, your biggest concern is overstocking density and limited ventilation.

Let me try to explain for the sake of new farmers joining the poultry business.



The ideal poultry shed should provide the birds with a comfortable environment and protect them from the extremities of the prevailing weather (rain, wind, sunshine, heat, chills, etc.).

The unit should provide adequate space for the flock. The ideal stocking density for layers at the point of lay should be two square foot per bird (2sqfoot/bird) in normal tropical weather conditions.

In the coastal regions with high ambient temperatures and high humidity, this can be increased to 3sqfoot/bird.

It is good practice in our type of weather to build open-sided walls to allow natural ventilation and have an east-west orientation to minimise the amount of sunlight entering the house directly.

It is important that the house be rectangular in shape and have perimeter wall not higher than three feet (3) on the longer side and making the total height of not less than 7 feet from the floor.



The wall can be made from, stones, iron sheets, timber, silver board, or bricks.

The rest of the side of the wall should have a chicken wire mesh. The roof of the house should have a reflecting surface and be pitched with overlaps to aid in ensuring that the house is comfortable and well-ventilated.

Cemented floors are the best finishing as they are easier to clean. There should be a foot -bath at the entrance of the house for those entering the house to disinfect their footwear.

To reduce the risk of rodents gaining entrance into the flock unit, clear all the vegetation in area 3-5 metres around the flock house.

The feed store should also be separate from the house. The flock house should be constructed in isolated areas to minimise the risk of contamination.

The flock house should be fenced to exclude stray animals and visitors. The doors should always be locked.

The wire mesh on the sides of the house should be of a small gauge to prevent wild birds, cats, dogs, and rodents from accessing the units.

In poultry farms, an all-in-all-out system is the best management practice as it prevents the buildup of disease-causing organisms and disease outbreaks.

In case the farmer wants to keep flocks of different ages, then each flock must be housed on its own with a minimum distance of 100 feet between them.

Ventilation

Ventilation can be described as the circulation of fresh air through the flock house and exhaustion of stale air out of the flock units.

This is achieved by the air passing from one side of the house and exhausting through the opposite side.

Ventilation of poultry houses serves several functions including, removing excess heat and moisture, providing oxygen while removing harmful gases, and finally reducing dust hence improving the air quality.

In the tropics, where houses are open-sided, ventilation is managed by opening the curtains from the top when it gets warm. This allows air from outside into the house.

When it gets cold the curtains are raised up and closed to restrict the flow of air. You must always allow minimum ventilation to avoid chicks getting suffocated.

Curtains are normally made from empty clean and disinfected feed sacks stitched together.

The curtain should be fastened to the sidewall at the bottom and opened from the top.

This will minimize wind or drafts blowing directly on the birds. To ensure effective ventilation, every effort should be made to open the curtain on both sides of the building to the same level unless the wind is consistently from one side of the flock house then the curtain on the side should be opened less than the other side.

Houses should be constructed to take advantage of the prevailing winds to improve the efficiency of natural ventilation.

Narrow houses (10 metre/33 feet or less) with higher-pitched roofs provide more natural air movement.

An east-west orientation of the flock house on its long axis reduces the solar heat level in the house.