Commercial Poultry Production and Hatchery Management

TEMPERATURE

• Temperature is the most critical single factor during incubation. Initially egg takes up the temperature from its surroundings, but as development proceeds, the embryos generate its own body heat.
• Optimum temperature requirement for the development of chicken embryo is 37.5 to 37.7 ⁰C (99.5 to 99.8 ⁰F) for the first 18 days and 36.1 to 37.2 ⁰C (97 to 99⁰F) for the rest three days.
• Keep a temperature of 2⁰F more in still-air incubator to that of forced air incubator to compensate for the temperature layering within the incubator.
• Developing embryos are very sensitive to temperature especially for high temperatures than low temperatures.
• An increase in temperature of 0.5⁰C over the required temperature results in early hatching, increased dehydration and smaller chicks.
• A further increase will lead to rough navels and weak chicks and sharp drop in hatchability.
• Temperature of 46 ⁰C for 3 hours or 50 ⁰C for only one hour will kill all the embryos.
• Low temperatures will delay the hatch, lower the hatchability and the chicks are with unhealed navels, more of culls and early mortality.
• Minor fluctuations (less than ½ degree) above or below the recommended temperatures are tolerated, but do not let the temperatures vary more than a total of 1⁰C.
• The temperature is measured at the level where the embryos develop (at the top of the egg).
• Do not allow the thermometer's bulb to touch the eggs or incubator. Check the thermometer for its accuracy.
• An error of one degree for 21 days can seriously affects the embryonic growth.
• Temperature is the easiest hatching function to regulate, provided the machine has a good set of controls.
• It is better to install a temperature sensitive alarm to warn the persons regarding the potential danger of the developing embryos.
• Temperature alarms are usually constructed with two temperature sensors.
• One is set to activate the alarm if the temperature drops below 97 or 98^oF.
• The other sensor is set to activate the alarm if the temperature goes above 102^oF.