Lung volume of meat-type chickens

Area of Science:

• Poultry Science
• Comparative Physiology
• Animal Husbandry

Background:

• Ascites syndrome in meat-type chickens is linked to pulmonary hypertension, often caused by inadequate lung capillary capacity or oxygen exchange.
• Rapid growth rates in modern broilers may exacerbate physiological challenges, including insufficient lung development relative to body mass.

Purpose of the Study:

• To quantify the changes in lung volume (LV) as a percentage of body weight (BW) in meat-type chickens throughout their growth period.
• To assess the potential relationship between declining LV/BW and the incidence of ascites in fast-growing broiler populations.
• To advocate for the inclusion of LV estimation in selection programs for meat-type chickens.

Main Methods:

• Lung volume (LV) was determined in meat-type chickens using the water displacement technique.
• LV was calculated as a percentage of the chicken's body weight (BW).

Main Results:

• The percentage of LV/BW showed a significant decline from 2.02 ± 0.190% at day 1 to 1.38 ± 0.163% by day 144.
• This age-related decrease suggests that lung capacity may not keep pace with rapid body mass increase in broilers.

Conclusions:

• A declining lung volume relative to body weight in meat-type chickens may predispose them to pulmonary hypertension and ascites.
• Integrating methods for estimating lung volume into selection strategies is recommended to improve broiler health and reduce ascites incidence.