Imagine living somewhere in the country where thugs and vandalism is common but your home has no fence! You are vulnerable to attacks, aren’t you? In chicken rearing, the egg shell plays a very crucial role in holding the egg content and generally protect the egg from damage. It also allows for gaseous exchange, a critical function especially during embryonic development.
Weak Shells In Layers
Often, we find some eggs with weak shell in the laying nest as we collect the eggs and we feel bad about the situation. This egg cannot be incubated, neither does it have any economic value in the market. Sometimes we end up cursing the hen that laid such egg without realizing that we have may have a blame to take as well. Temperature regulation should be the first consideration for any chicken farmer even before starting the venture. We all know that extremes of temperatures (both low and high) are detrimental as far as chickens’ productivity is concerned. But from egg-shell’s perspective, I will pay attention to high temperature.
Chicken body temperature
Chickens are better adapted to keeping warm than keeping cool. Normal internal body temperature is 41.3ºC which is just a few degrees centigrade below the temperature at which enzyme inactivation and tissue death begins. The ideal environmental temperature for hens is 12.8ºC, a long way short of the typical daytime temperatures in tropical Asia where heat stress is a huge potential problem. Hens actively maintain their body temperature by:
• Reducing heat absorption by staying in the shade
• Reducing heat production by reducing feed intake and activity
• Increasing heat loss through evaporative cooling
Do Chicken Have Sweat glads?
Birds do not have sweat glands and therefore rely on PANTING (passing air over the moist surfaces of the respiratory tract) to dissipate heat. This causes excessive loss of carbon dioxide, needed to make calcium carbonate in the uterus. The net result is lower egg shell quality with soft shelled eggs a common occurrence. Failure to maintain body temperature leads to a general fall in egg production.
Having said this, the farmer should therefore help their layers to keep cool by:
• Locate hen houses in the shade
• Using open-sided houses orientated east-west to avoid sun shining directly inside
• Constructing wide roof overhangs and placing the roof angle north and south to avoid the direct rays of the sun
• Providing air movement and evaporative cooling.
Try this and you will not only relieve your birds from heat stress but also get eggs with quality egg-shell.
Alongside the suggested approach, you are also advised to ensure adequate supply of important minerals like calcium and phosphorus for layers.