Effect of Air Quality on Broiler Growth Performance

Recent tests in Mississippi found that carbon dioxide concentrations in chicken houses did not affect the growth performance of broilers aged 28-49 days. The researchers explained that in order to control moisture in the house, it is usually necessary to use a ventilation fan for ventilation, which usually causes the carbon dioxide concentration in the house to be lower than a reasonable level.

Modern broiler houses have continued to improve in terms of air leakage. This ensures the proper operation of the ventilation system and maintains a suitable housing environment, according to Joseph L. Purswell of the USDA-AR Poultry Institute of Mississippi and its Mississippi State University. Partners have published their most recent paper in the International Journal of Poultry Science. They also said that rising fuel prices in recent years have led farmers to reduce the minimum ventilation to save fuel, and this has led to an increase in carbon dioxide concentrations in the houses.

Previously, researchers have found that high concentrations of carbon dioxide have some negative effects on the growth performance or mortality of broilers aged 14-28 days.

Scientists from Mississippi conducted four trials to assess the effect of increased carbon dioxide concentration on broilers aged 28-49 days. 300 straight-run broilers were used in each experiment and housed in a controlled environment house. Carbon dioxide concentrations were maintained at 0, 2500 ppm (all days), 2500 ppm (daytime) and 4500 ppm (night) during 28-42 days of age. Or 2500ppm (daylight) and 6500ppm (night).

The results of the study found no difference in the performance of each treatment - body weight, body weight gain, feed intake and feed conversion - and processing yield. However, they did find that broilers tend to have higher body weights, body weight gains, and feed intakes during temperature changes. In addition, although there was no significant difference in processing and production data, there was a significant difference in chicken breast weight, but the ratio of chicken breast meat production to carcass weight was not affected by treatment.

Purswell and his collaborators concluded that by using the ventilation rate to maintain the commercial broiler house under test conditions, the results showed that although the heating demand decreased correspondingly when the carbon dioxide was maintained at 4500 or 6500 ppm by reducing the ventilation rate, such ventilation rate It is not enough to remove excess moisture from the house.

Therefore, the authors believe that using the current engineering design guidelines, the ventilation rate used to control the moisture often makes the carbon dioxide concentration in the house below a reasonable concentration level.