MODERN DAY POULTRY FARMING Akhlaq Ahmad

07-12-2015

Poultry Housing• Hens naturally were wild birds.• Domesticated with passing time to full fill human protein

requirement.• Since ages backyard poultry is part of human civilization.• With rapid increase in human population, the demand for protein

increased enormously which is met by improving birds efficiency genetically.

• To manage large numbers we confined them.• Conventional farms were initially built with less width so that air

may cross through natural air current.• Conventional houses worked a lot in moderate climatic zones

but factors like increase in disease load, noxious gases, improper control of temperature, decreased efficiency were questions to be answered.

• Single answer to all these questions was Modern Environmentally controlled house.

Broiler Farming

• At commercial level Open shedControl Sheds

Open shed vs Control shed

Control shed Open shed

Most of the things are automatic. Every thing manual

Construction cost very much high. Construction cost very low

Production satisfied Production not satisfied

Open Shed• Every thing manually• i.e Feeding , Watering

Vaccination etc.• Tem in open shed difficult

to maintain.• RH also not retain

according to our requirement.

Open shed

DisadvantagesBecause management not under our control so

• Production low• FCR low• Body wt vary from bird to bird• High labour cost• At the end not satisfy farmer

Open shed

Advantages• Low construction &

Running expenses (electricity , diesel etc.)

• Birds are more resistant to diseases then control shed.

Control shedAdvantages• Almost Every thing auto

control

(feeding , watering , may be vaccines, Tem , RH , Ventilation , etc.)• Low labor cost• Wt gain high• FCR high

Control shed

Disadvantages• Construction cost high• Running cost high• Less immune birds then

open shed

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Ventilation System

Poultry house ventilation is necessary because

• Birds need good environment.• We need more fresh air to full fill the needs due to higher

metabolic rate of birds.• We need more fresh air to full fill the needs due to higher

stock densities.• We want to expel excessive heat if any.• We need dry litter despite high density.• We want to expel noxious gases e.g. ammonia. • Ventilation in a poultry house supplies fresh air that is

essential to sustain life. It also helps reduce the extremes of temperature, humidity and air contamination to tolerable limits for confined chickens

Environmental conditions in Pakistan• We are dependant upon the environmental conditions i.e.

climate of the region in which farm is to be constructed.• Due to the location, Pakistan Climate is temperate.

• Pakistan has four seasons:

• A cool, dry winter from December through February.• A hot, dry spring from March through May.• The summer rainy season, from June through September.• The fall is a retreating monsoon period of October and

November.

• The onset and duration of these seasons vary somewhat according to location.

Extreme temperatures and humidity in Pakistan

• Climate of Pakistan has great regional variation. • The difference in temperature between day and night is

immensely substantial.

• The Extremely hot temperature may go up to 45°C to 50+°C in the summers.

• The Extremely low temperature may comes to 0°C or even less in the winters.

• Humidity ranges between 10% to 100%.

• Points of concern are Extreme temperatures and Humidity.

Ventilation systems• Generally divided into two types: • (1) Natural air flow system• Natural air currents are allowed to enter into the house.• Fit for areas where outside temperature does not exceed 33°C.• House width may be maximum around 30 feet for this system.• Conventional farms are built on this principle • Not best fit for our conditions.• (2) Mechanical air movement (fans).• Mechanical air movement is required to ventilate a house in all

climatic conditions. This system suits our climatic conditions.• Mechanical systems use electric fans as principal components to

exchange air in the building. They can be divided into two distinct types(Positive pressure and negative pressure). 

Positive pressure System:

• In the positive pressure system, fans are arranged to push fresh air in to the building.

• Creates air velocity which produces wind chill effect.• For rearing at higher stock densities in extreme climatic

conditions this system is not very much effective.

Negative Pressure system:

• In the negative pressure system, fans are arranged to expel air from the building. In doing so, they create a partial vacuum or negative pressure inside the house. The pressure difference pulls fresh air through inlets into the house.

• The location, distribution and size of the fans and inlets are critical if all areas of the house are to be ventilated.

• We may term this system best fit for our climatic conditions.

Negative pressure system operation in different weathers• To discuss this system in changing climatic conditions we may mainly divide it in to;

• 1-Cold Weather Ventilation (Minimum ventilation)• 2-Hot Weather Ventilation (Tunnel ventilation)

• 3-Optimum weather ventilation (Transitional ventilation)

Minimum Ventilation

• Minimum ventilation is used to provide fresh air inside the house during cold weather. It removes excessive moisture and minimize the heat loss.

• Fans exhaust air out of the house by creating a slight negative pressure inside the house. Due to the negative pressure, fresh air is pulled into the house through some planned air inlets.

• The air inlets are installed either in the ceiling or high on the house side wall. These inlets are designed to direct air across the ceiling allowing it to mix with warmer air located there and to heat up before coming into contact with the birds.

• Check temperature and determine the heating necessity. Doing this will help to minimize heating costs. For large scale commercial production, you can install automatic computer controllers.

Objectives of minimum ventilation

• Provide fresh air containing oxygen and exhaust ammonia, carbon dioxide and other gases.

• Provide an adequate air exchange to control moisture.• Get rid of excessive heat if any.• Provide an in house airflow pattern that avoid chilling

birds.• Reduction in fuel cost by minimizing heat loss.

Modern house: Tools of minimum ventilation

• To achieve the objectives of minimum ventilation, certain tools are required based on scientific principles.

• Most important tools are exhaust fans and air inlets(vents) and other accessories to operate fans and vents properly.

• If we construct a new house we may have the knowledge that how many fans and vents may be installed in that house.

Exhaust fans

Expel air out of the building. In market there are different types of fans available with varying capacity. Normally for minimum ventilation 9000 CFM capacity fans are used but we may also use fans of any capacity.

Calculation: number of fans for a house

• Though this topic belongs to tunnel ventilation but to ensure continuity we have to discuss # of fans to be installed in a house first. Formula to calculate number of fans is as follows.

No Of Fans = Cross Section x Desired velocity CFM of one fan

• (Cross section= width * height of the house)• Desired velocity in our climatic conditions must be more than

length of the house to get less than 1 minute air change. • CFMs of air expelled by a single fan depends upon the size

and efficiency of fan recommended by the manufacturer.

Tools of minimum ventilation

Controllers: It is an electronic device that collect information

from different sensors and execute scheduled tasks. Static

pressure switch provide information to controller and

controller operates power track to open or close vents accordingly.

Inlets(vents): fresh air is pulled into the house through vents. Vents are distributed through out the house in uniform pattern. Number of vents depends upon size of vent and

40% of total capacity of fans installed in house so that air may

pass at a velocity of 700 Feet per minute .

Calculation;Number of vents for a house

• Area for vents=Total no of fans x cfm of one fan x 40% 700 f.p.m

• Total no of vents=total area for vents Area of one vent

• (40% of total ventilation is maximum limit of minimum ventilation).

• (Air should pass across the vent at a speed of 700 fpm).• We can purchase vent of any dimension from market.

Greater the area of vent, Less would be the number of vents and vice versa which are supposed to be installed in house uniformly.

Tools of minimum ventilation

Static pressure sensor: sensor is installed with controller to sense

static pressure and give feed back to controller so that it may

open or close the vent according to static pressure to avoid chilling.

Power track : it is an electrical device attached mechanically to vents and on the information of controller, Operates the vents

according to the static pressure.

Minimum ventilation:Tools working sequence

• Tunnel Fans : Off• Min. Ventilation Fans : on

• Cooling Pad : Closed• Vents : Open

• Evaporative Cooling : Off• Tunnel door : Closed

•Thanks for the Attention