Progress 08/01/08 to 07/31/11
Outputs
Progress Report Objectives (from AD-416) 1) To establish a working model of Gangrenous dermatitis (GD) in 4- to 8- wk-old broilers; 2) To determine the effects of GD in vivo; we will challenge parental lines A and B; and 3) To challenge experimental chickens from line C (high vs. low) and monitor for the development of GD. Approach (from AD-416) Our laboratory will collect field isolates from commercial chickens with active GD from 2-3 different geographical locations around the country. Samples will be processed for bacterial isolation under anaerobic conditions. Samples will be tested for purity, and bacterial isolates will be further characterized utilizing the API strip-32A. After we have identified several bacterial candidates (Clostridium septicum, Clostridium perfringens type A, and Staphylococcus aureus), we will combine these bacteria in a chemostat utilizing continuous flow culture methodologies. We will also take birds exhibiting clinical signs of GD and place their intestinal contents into a separate chemostat. Utilizing this in vitro methodology will potentially allow us to re-create the mixed microflora populations of gastrointestinal system of GD birds. There are many influential factors that contribute to GD. As we begin the developmental stages of the model, we will carefully introduce new parameters so that we can re-create a compatible field model. We will utilize the information that we have learned from our previous experience in developing our Necrotic enteritis model and apply these same methodologies to GD. We will carefully evaluate parameters which will include: environment, antibiotic growth promoters, bacterial populations, viruses, protozoa, feed composition, and vaccination programs. Throughout the process of model development, we will continually evaluate data collected to proceed as accurately as possible. After a disease model has been created, we will evaluate several parental lines of Cobb- Vantress, Inc. The goal of this project is to develop a working model of gangrenous dermatitis (GD) in market-age broilers. This disease state in commercial poultry results in carcass condemnation at the poultry processing plant; losses to the U.S. poultry industry average well over $10M each year. In FY 2011, field isolates collected from commercial chickens from several different geographic locations and which contained the Clostridium septicum pathogen were orally administered to broilers. This produced typical GD-like symptoms, showing that GD can be intentionally and reproducibly induced in birds. This knowledge will be of significant value to poultry veterinarians and others in their efforts to develop and evaluate effective intervention/control programs for GD. Success in such efforts will reduce the incidence and severity of GD in commercial poultry production, thus enhancing poultry production efficiency and profitability. Over the life of this project, significant advances were made in the development of a repeatable working model of GD and also of the necrotic enteritis disease that is caused by Clostridium perfringens. This project expired in FY 2011.
Impacts
(N/A)
Publications
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Progress 10/01/09 to 09/30/10
Outputs
Progress Report Objectives (from AD-416) 1) To establish a working model of Gangrenous dermatitis (GD) in 4- to 8- wk-old broilers; 2) To determine the effects of GD in vivo; we will challenge parental lines A and B; and 3) To challenge experimental chickens from line C (high vs. low) and monitor for the development of GD. Approach (from AD-416) Our laboratory will collect field isolates from commercial chickens with active GD from 2-3 different geographical locations around the country. Samples will be processed for bacterial isolation under anaerobic conditions. Samples will be tested for purity, and bacterial isolates will be further characterized utilizing the API strip-32A. After we have identified several bacterial candidates (Clostridium septicum, Clostridium perfringens type A, and Staphylococcus aureus), we will combine these bacteria in a chemostat utilizing continuous flow culture methodologies. We will also take birds exhibiting clinical signs of GD and place their intestinal contents into a separate chemostat. Utilizing this in vitro methodology will potentially allow us to re-create the mixed microflora populations of gastrointestinal system of GD birds. There are many influential factors that contribute to GD. As we begin the developmental stages of the model, we will carefully introduce new parameters so that we can re-create a compatible field model. We will utilize the information that we have learned from our previous experience in developing our Necrotic enteritis model and apply these same methodologies to GD. We will carefully evaluate parameters which will include: environment, antibiotic growth promoters, bacterial populations, viruses, protozoa, feed composition, and vaccination programs. Throughout the process of model development, we will continually evaluate data collected to proceed as accurately as possible. After a disease model has been created, we will evaluate several parental lines of Cobb- Vantress, Inc. The goal of this project is to develop a working model of gangrenous dermatitis (GD) in market-age broilers. This disease state in commercial poultry results in carcass condemnation at the poultry processing plant and results in losses to the U.S. poultry industry of tens of millions of dollars each year. In FY 2010, field isolates collected from commercial chickens from several different geographical locations and which contained the Clostridium septicum pathogen were orally administered to broilers. This produced typical GD-like symptoms. This work, establishing that GD can be intentionally induced in birds, will be of significant value to poultry veterinarians and others in their efforts to develop and evaluate effective intervention/control programs for GD. Success of such efforts will reduce the incidence and severity of GD in commercial poultry production, thus enhancing production efficiency and profitability. Project work thus far has made major advances in the development of a repeatable working model of GD and also of the necrotic enteritis disease which is caused by Clostridium perfringens. This project was scheduled to expire in FY 2010 but was extended through 07/30/2011.
Impacts
(N/A)
Publications
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Progress 10/01/08 to 09/30/09
Outputs
Progress Report Objectives (from AD-416) 1) To establish a working model of Gangrenous dermatitis (GD) in 4- to 8- wk-old broilers; 2) To determine the effects of GD in vivo; we will challenge parental lines 12 and 58; and 3) To challenge experimental chickens from line 59 (high vs. low) and monitor for the development of GD. Approach (from AD-416) Our laboratory will collect field isolates from commercial chickens with active GD from 2-3 different geographical locations around the country. Samples will be processed for bacterial isolation under anaerobic conditions. Samples will be tested for purity, and bacterial isolates will be further characterized utilizing the API strip-32A. After we have identified several bacterial candidates (Clostridium septicum, Clostridium perfringens type A, and Staphylococcus aureus), we will combine these bacteria in a chemostat utilizing continuous flow culture methodologies. We will also take birds exhibiting clinical signs of GD and place their intestinal contents into a separate chemostat. Utilizing this in vitro methodology will potentially allow us to re-create the mixed microflora populations of gastrointestinal system of GD birds. There are many influential factors that contribute to GD. As we begin the developmental stages of the model, we will carefully introduce new parameters so that we can re-create a compatible field model. We will utilize the information that we have learned from our previous experience in developing our Necrotic enteritis model and apply these same methodologies to GD. We will carefully evaluate parameters which will include: environment, antibiotic growth promoters, bacterial populations, viruses, protozoa, feed composition, and vaccination programs. Throughout the process of model development, we will continually evaluate data collected to proceed as accurately as possible. After a disease model has been created, we will evaluate several parental lines of Cobb- Vantress, Inc. Significant Activities that Support Special Target Populations This is a new project, with the goal of establishing a working model of gangrenous dermatitis (GD) in market-age broilers. In FY 2009, field isolates from commercial chickens with active GD were collected from several different geographical locations around the country. Work was initiated on analysis of these samples by continuous-flow culture methodologies. As work under the project progresses, it is expected that technology and protocols will be developed for use by poultry veterinarians in application of effective intervention/control programs for CD. Such programs will reduce the incidence and severity of this disease in commercial poultry production, thus enhancing poultry production efficiency and profitability.
Impacts
(N/A)
Publications
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