Title: Effects of Escherichia coli Challenge and Transport Stress on Hematology and Serum Chemistry Values of Three Genetic Lines of Turkeys Authors
|Anthony, Nick - UNIV OF ARKANSAS|
|Nestor, K - THE OHIO STATE UNIV|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 17, 2008
Publication Date: September 1, 2008
Citation: Huff, G.R., Huff, W.E., Rath, N.C., Anthony, N.B., Nestor, K.E. 2008. Effects of Escherichia coli Challenge and Transport Stress on Hematology and Serum Chemistry Values of Three Genetic Lines of Turkeys. Poultry Science. 87:1-8. Interpretive Summary: Male and female turkeys from different genetic backgrounds were compared for their response to a respiratory bacterial challenge and transport stress. One turkey line was slow growing and had been selected for increased egg production. The other two lines were fast growing, one an experimental line selected for increased 16 week body weight and the other a commercial line. Birds from each line were challenged at 14 weeks of age by injecting bacteria into the respiratory system. Eight days after the injection they were subjected to a transport stress procedure that included a total of 12 hours holding time in a transport vehicle. At the end of the transport procedure, birds were returned to their pens and provided with feed and water. The following morning all birds were bled. Blood was analyzed for biochemical changes and changes in red blood cell characteristics. The stress of bacterial challenge followed by transport decreased some of these parameters and increased others. An important change was that the levels of creatine kinase, an indicator of muscle growth and damage, were over 6-fold higher in challenged and transported birds from the commercial line compared to non challenged commercial line birds and iron levels of the transported commercial line males were 3-fold lower than non challenged male controls. Also, the levels of both iron and alkaline phosphatase were lower in the fast growing lines as compared to the slow growing line. These two blood chemicals were also the only parameters influenced by gender, with males having higher levels of both compared to females. Previously, birds from the fast growing lines were shown to have white blood cell changes that indicated a greater response to stress and they were also more susceptible to bacterial disease. The highly significant differences seen in the commercial turkey line for these blood parameters suggests that they may be useful for profiling turkeys to determine their response to transport stress.
Technical Abstract: Males and females from 3 genetic lines of turkeys were compared for their response to an Escherichia coli airsac challenge followed by transport stress (Transport). The turkey lines were a slow growing line selected for increased egg production (Egg line), a fast growing line selected for increased 16 wk body weight (F line), and a commercial line (Comm line). Birds from each line were challenged at 14 wk with an air sac injection of 5,000 to 10,000 cfu of E. coli and were subjected to a transport stress procedure 8 d after the challenge that included a total of 12 h holding time in a transport vehicle. At the end of Transport, birds were returned to their pens and provided with feed and water. The following morning all birds (n = 10 to 19 birds/line) were bled, which was 1 d after the start of Transport and 9 d after challenge with E. coli. Whole blood was analyzed using the Cell-Dyn 3500 blood analysis system (Abbott Diagnostics) and serum chemistry was measured using the Express Plus analyzer (Ciba-Corning Diagnostics Corp). Transport significantly decreased hematocrit, hemoglobin, mean cell volume, mean corpuscular hemoglobin, glucose, triglycerides, cholesterol, phosphorus, iron, albumin, and alkaline phosphatase (AP) levels and increased uric acid, blood urea nitrogen, alanine aminotransferase, aspartate aminotransferase, and creatine kinase (CK). Line differences were variable, but the levels of both iron and AP were indirectly correlated with growth rate. Iron and AP were also the only parameters influenced by gender, with males having higher levels of both compared to females. The CK levels were over 6-fold higher in transported Comm line birds and iron levels of transported Comm males were 3-fold lower than controls. Previously, the growth rate of these lines was positively correlated with increased heterophil to lymphocyte ratios and susceptibility to colibacillosis. The highly significant differences seen in the Comm line for these commonly measured blood parameters suggest that they may be useful for profiling flocks to determine their response to transport stress and feed withdrawal.