well over 32°C. Seven days after arrival, bird weights were registered. At the end
of the production period, at day of delivery to the processing plant, mortality, ...
Feed conversion (at 1500 grams)
Figure 1: The relationship between floor temperature on day of arrival and feed conversion
Floor temperature on day of arrival in °C
Heating a broiler house prior to stocking improves bird performance, especially when using air heaters
Broilers get a better start on a warm floor, grow faster and have improved feed conversion than on a cold floor. That is the outcome of a Dutch field trial.
Daily gain in grams per day
Figure 2 - The relationship between floor temperature on day of arrival and daily gain
Floor temperature on day of arrival in °C
By Wiebe van der Sluis
B
roilers grow faster and require less feed when placed on a warm, preheated floor compared to those that start on a cold floor. That was the conclusion of the Dutch cooperative feed manufacturer ABCTA and its associated hatchery Cobroed, from a trial involving over 4.5 million broilers in 200 houses. The concrete floor temperature was measured in different areas using an infra-red thermometer during delivery of the day-old chicks. The results of the measurements were surprisingly different between the various farms. Some houses had a floor temperature below 20°C and others were well over 32°C. Seven days after arrival, bird weights were registered. At the end of the production period, at day of delivery to the processing plant, mortality, daily gain and feed conversion data were calculated and compared to the floor temperature data. From the data collected it became clear that a low floor temperature at start has a negative effect on final flock uniformity. This could be seen during the grow-out period and again at the processing company. In addition, flocks raised in an environ-
Figure 3 - The relationship between floor temperature on day of arrival and mortality ment with low floor temperatures showed depressed daily gains and increased feed conversion. The graphs show that the graphs (Figure 1 and 2) within the 25 and 30°C floor temperature range every degree increase affects daily gain by 0.3 gram and feed conversion by about 0.5 points. This means that with a floor temperature Floor temperature on day of arrival in °C of 25°C, the feed conversion for a bird of 1500 grams is 0.025 higher than that for a bird spread more evenly over the whole house; reared at a floor temperature of 30°C. The in addition one can save quite a bit on endifference in daily gain within this time ergy costs during rearing. These savings frame is about 1.5 grams or about 60 balance out the extra cost of pre-heating. grams over 40 days. Interestingly, mortaliWhen using combustion systems, proper ty is barely affected by the initial floor pre-heating prior to arrival of the birds is temperature (Figure 3). even more important. These systems proIt is often thought that heating up the duce fumes (especially carbon dioxide) house prior to the day the chicks arrive is and have a negative effect on the in-house rather costly. The fact is that saving on air quality. They may therefore decrease these costs is counter-productive. Pre-heatbird performance during the first weeks ing gives the birds a better start and they of life. ■
