dc.description.abstract | An unwanted byproduct of commercial broiler chicken grow out is thousands of
tons of litter. This litter is the material on which the broiler chicken spends its entire life.
Litter consists of a starting material, in the southeast United States normally pine shavings, plus
excreta, feathers, feed, litter beetles, parasites and bacteria. While some litter is used for
other applications, such as plant fertilizer or livestock feed, most of it is reused from one flock
to the next. With proper management, the litter can be maintained in good condition for several
years. A problem associated with litter is the high number of bacteria that survive in the litter
environment. Most of these bacteria are not harmful, but some such as Salmonella enterica, can
cause serious illness in humans through contaminated meat. Other bacteria, such as Clostridium
perfringens, can cause illness in both chickens and humans. In both instances, the economical
impact of such illness is substantial, reaching into the millions of dollars in losses.
The majority of previous research into litter bacterial makeup has utilized the hand grab method of
sampling that simply removes the top inch or two of litter. From this sampling, researchers have
extrapolated the bacterial makeup of the entire litter bed. However, most commercial broiler houses
have more than two inches of litter. It is the author’s belief that previous findings concerning
the amount of bacteria present in litter could be erroneous. Therefore the first phase of this
dissertation is to identify the
concentrations of several pathogenic bacteria, their stratification from top to bottom of
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the litter and location of the bacteria within the house. Sampling would include the entire
depth of the litter bed, including the hard dirt pad underneath. This would be achieved utilizing
traditional culture and second generation high throughput sequencing methods.
The second phase aims to discover any litter management techniques that would reduce the pathogenic
bacteria load in litter, specifically Salmonella. In recent years, the emphasis on controlling this
pathogen has switched from processing plant to more on
farm control methods. The methodology to be examined will be the application of several commercial
and novel litter amendments that would normally be used for ammonia reduction on a commercial
poultry farm. These amendments consist of several acid salts, a liquid acid and several
nonpathogenic bacteria. The acidic amendments function by lowering the pH of litter from its
normal basic pH, around 8 to 9, to an acidic pH of 5 or less. This reduction in litter pH not only
traps ammonia, but could reduce the
concentration of pathogenic bacteria present in litter. | en_US |