ST. PAUL, Minn. -- Overall, the condition of the egg industry throughout the southeastern U.S., from a disease standpoint, is quite good. That is not to imply that there are not areas that need improvement, such as biosecurity and vaccination administration.
The major disease or syndrome that I encounter throughout my travels continues to be peritonitis in layer flocks that are reaching peak production. This is normally diagnosed as an E. coli infection. The root cause of this problem is likely multi-faceted and I do not think that E. coli alone is the primary pathogen. In many instances, the complexes and/or farms that are having the peritonitis problems are seeing mixed Mycoplasma gallinepticum results on serology when submitted to a laboratory.
These mixed results consist of plate test positives and occasional positive hemagglutination inhibition (HI), but the flocks rarely become 100 percent plate or HI positive. Occasionally, I will see these flocks go from positive to negative in a few months time. There are also potential infectious bronchitis problems in many of these locations that may be complicating the situation. Air quality, water quality, possible cloacal tears from excessive early egg size or early onset of production all may be contributing factors.
Laryngotracheitis continues to rear its ugly head in the fall and winter in areas like Georgia and Florida. The use of the chicken embryo origin vaccines in many areas may help contribute to the viral load in the area and poor administration of these vaccines can lead to rolling of the virus through the flocks. Poor vaccine administration of the Vectored infectious laryngotracheitis product has also led to some breaks in one area that I am aware of. Likewise, there are a few cases of fowl pox in the Southeast that again is likely due to poor vaccine administration or lack of administration of the vaccine.
One flock in particular also has about 20 percent of the flock with cataracts leading me to think that the flock was not vaccinated or very poorly vaccinated. In my travels, I find fewer and fewer operations that are checking for pox takes after administering this vaccine. This needs to be addressed as I feel that the administration of this vaccine has gotten worse and worse as the industry has consolidated and the flock size has increased.
Infectious bronchitis virus variants (GA98) are getting a lot of attention in some areas and may, in fact, be causing some production drops and shell quality issues being seen in North Georgia. Time will tell on that particular issue, as there may be a GA98 vaccine produced soon.
Marek's disease has not been an issue at any of the locations that I visit and likewise from the diagnostic laboratories that I contacted. There are some flocks that will experience a low level of leg paralysis during grow, but the amount of mortality associated with this is very low (0.25 percent to 0.5 percent).
Management problems associated with ventilation, feeding, lighting programs, etc., continue to occur here and there.
Unfortunately, there are still many layers in parts of the Southeast that are raised on the floor in old broiler houses. This creates problems with body weight gains in the summertime and parasite problems year round. I am concerned that throughout our industry, much less time and money is spent attending to pullet issues than layer issues and that is backwards from what it should be. If the pullets are grown well and are in good condition and on target, the layer flocks really have it easy. Certainly they can mess up good pullets with poor management, but they are never going to be able to correct a poorly grown pullet.
Overall, the industry in the Southeast remains in good shape from a disease standpoint.
Dr. John G. Brown is with Centurion Poultry Inc. in Lexington, Ga. This article is drawn from one Brown presented at the 2005 Midwest Poultry Federation Convention in St. Paul, Minn.
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