Heatstress which is the stress or discomfort brought about by high atmospheric temperature especially in the poultry house has been found to have serious adverse effects on the laying birds. Temperature over 38°C can lead to mortality in birds affected. Birds kept under intensive management system i.e in cages perform better at temperatures between 18 to 24°c ambient temperature but can still cope at slightly higher temperature. This is due to the fact that birds lack sweat glands and are fully covered by feathers which limit their ability to manage heat to panting. As temperature becomes higher, their appetite decrease, they drink more water, start panting, become prostrate and die as temperature becomes higher than 38°C. In laying birds, production automatically reduces with all manner of egg sizes and shell shapes. Just as in humans, heavy and older birds are more adversely affected than lighter and younger birds. So much can be done to help birds adapt better and produce more efficiently during hot weather which include management of several components. They include : 1) Management of their housing. 2) Water management 3) Feed management 4) General management. 5) Therapeutic management For optimal performance of your birds , the construction of the pen must be right. Ie: the direction must be rightly done. The long axis of the pen must be in East -West direction so that the movement of the sun will be on the long ridge of the roof not on the sides. Also, the overhang or the span of the roof at sides be at least 1 to 1.5m long to prevent the rays of sun from directly heating the birds which also provides shade and some level of air flow. The height of the pen must be at least 10 feet at the sides i.e the eaves while the gable be 15 feet. This help limit the heat radiation from the sheets to the birds in the cages. Roofing sheets should be asbestos or sliver aluminum sheets that will reflect rays of sun off is also effective in reducing temperature of the pen. When constructing laying pen, a ridge must be made in the center of the roof to allow hot air be pushed out. Use of palm fronds, straws etc can be placed on the roof to insulate it and thus lowering the temperature of the pen. For big farms, use of sprinklers that will sprinkle cool water on the roof to lower the temperature of the pen or foggers that will create fine cool mist in the pen to reduce the temperature too.
Trees can be planted beside the pen to create shade and cool airflow. When these are done you can effectively reduce the ambient temperature by at least 2-3°c which can mean a lot between production loss or gain.
To help our birds adapt better, these are the things to do: 1)Provision of sufficient cool water throughout the day especially in the heat of the day. If you use open drinker, refill with cool water in the afternoon but if you use nipples, make sure your overhead tank is under shade to prevent the heating up of the water. Also, drain the water in the pipes at least twice during the heat of the day until cool water is flowing out of it. Use of ice blocks into their water to cool it too, can make a lot of difference as birds will not drink warm or hot water. 2) Feed your birds half of the daily ration very early in the day around 5am and the remaining half around 4pm later in the day when temperature will be cooler. Supply only cool water throughout the hot afternoon. This will necessitate that you put on the light till around 10pm to help them finish their ration aside the other good effects of lightning in laying birds. 3) Regular use of multivitamins and electrolytes is advised too, to help them replace those lost due to heat. 4) Cool water could be sprinkled or sprayed into the air using sprayer to bring down the pen temperature. This could reduce the temperature by 3°c which means a lot to the birds. 5) Feed ration higher in protein and other nutrients except energy to prevent fat deposition which can lead to high mortality due to fatty liver hemorrhagic disease. Also high concentration of the birds in a small space or overstocking causes heat stress and you may suffer significant drop in production and slight increase in mortality than usual which can be alleviated but not totally stopped except the atmospheric temperature can be regulated. It is also good to know that heat stress may precipitate some diseases that under normal circumstances won't have occurred leading to spending more on drugs. You will have to spend more on multivitamins that have electrolytes and use of vita c for birds too at this time is highly encouraged.
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