Graded atmospheric oxygen level effects on performance and ascites incidence in broilers.
The effects of graded atmospheric O2 concentration (12, 14, 16, 18, and 20.6%) on chick performance and propensity to develop ascites were investigated using commercial male broilers. Chicks were housed in calorimetry chambers for 2 wk with incoming air diluted with N to provide the desired O2 concentration at thermoneutral (TN) ambient temperature. Day 14 body weight, weight gain, feed consumption, and gain-to-feed ratio increased (P < 0.01) as O2 concentration incrementally rose from 12 to 20.6%. Body weight was 138 g for the lowest atmospheric O2 level compared to 371 g for 20.6% O2. The greatest treatment difference occurred between the 12 and 14% O2 concentrations. Growth depression appeared related to feed consumption. Ascites heart ratio (AHR), ascites score (AS), right ventricular mass (RVM), and hematocrit (HCT) all increased (P < 0.01) as O2 concentration decreased. Blood HCT appeared to be a more sensitive indicator of physiological change attributable to atmospheric O2 than AHR, AS, or RVM. The data reported herein suggests that 19.6% atmospheric O2 is the minimal allowable level for housing birds within a relatively stress-free, TN environment to avoid cardiac and HCT changes related to ascites.
Beker
A
A
Department of Animal Science, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
Vanhooser
S L
SL
Swartzlander
J H
JH
Teeter
R G
RG
D000531:Altitude; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001201:Ascites / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D001835:Body Weight; D002645:Chickens / Q000502:physiology*; D004435:Eating; D006352:Heart Ventricles / Q000473:pathology; D006400:Hematocrit; D008297:Male; D009584:Nitrogen / Q000008:administration & dosage; D010100:Oxygen / Q000008:administration & dosage*; D011201:Poultry Diseases / Q000453:epidemiology* / Q000473:pathology; D015430:Weight Gain
D009584:Nitrogen; D010100:Oxygen