Evaluation of Air and Litter Quality with Microbiological Fluctuations in Commercial Broiler Facilities Using a Biological or Chemical Litter Treatment
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Litter Guard (LG) is a recently introduced poultry litter amendment consisting of a blend of different bacteria and soluble humates. LG is believed to reduce the ammonia emission rates and the concentration of bacteria in poultry litter. Poultry Litter Treatment (PLT) is a commonly used chemical litter amendment and is proven to reduce the pH and ammonia emission rates in poultry litter. Thus a comparative field study was conducted to evaluate the efficacy of LG compared to PLT in reducing ammonia and microbial load in poultry litter over three consecutive broiler flocks. Six commercial broiler houses (12.2 × 152.4 m) were screened for three consecutive flocks. Three houses were treated with LG 7 d before bird placement; 18.9L in 378.5 L water throughout the entire house. The other three houses were treated with PLT, 24 h before bird placement; applied in the central brooding area at the rate of 24.4 kg/100m2. For all three flocks litter samples were collected before application of treatments and at approximately 1, 8, 15, 22, 29, 36 and 43 d of age at four equidistant locations in each house. Litter samples were analyzed for pH, water activity, moisture and microbiological analysis. Microbiological analysis included enumeration of total aerobic, anaerobic, enteric, Cl.perfringens and E.coli (cfu/gm). Concurrent with litter sample collection a Drager CMS analyzer was used for ammonia measurements. At the time of each flock’s processing five hundred paws were collected from each house and lesion scored. Results showed that PLT application significantly (P < 0.05) decreased ammonia levels on d 1 compared with LG (37.9 vs. 59.4 ppm), but PLT was unable to maintain low levels after d 8. Litter sample pH levels were significantly reduced (P < 0.10) by PLT on d 1 compared with LG (7.91 vs. 8.43). Whereas LG application gradually decreased pH until d 22, showing a gradual rise thereafter. This delayed affect on pH may be related to the increased bacterial potential of the LG application with time. Aerobic bacterial counts were significantly decreased (P < 0.10) by PLT on d 22 compared with LG application (8.78 vs. 9.22) on all three trials. Anaerobic counts were significantly reduced (P < 0.10) by PLT on d 22 compared with LG (6.76 vs. 6.96) on all three trials. PLT may have contributed to a reduction in the growth potential of these two microorganisms after a given period of exposure. Cl.perfringens, enteric and E.coli counts fluctuated for the duration of the experiment. Footpad dermatitis assessment results indicate no detrimental effects attributed to either litter treatment. Compared to PLT, LG was less effective in maintaining low ammonia levels and both treatments were ineffective in maintaining bacterial levels.
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