An assessment of the effectiveness of four in-house treatments to reduce the bacterial levels in poultry litter.

Although the use of quicklime (CaO) and tarping are common handling practices aimed at the reuse of litter in the Brazilian poultry industry, few scientific studies have proven the effectiveness of these methods in reducing the pathogenic microbial load during fallowing. The objective of this study was to evaluate the following litter treatments: T1 no treatment (control), T2 quicklime (300 g m(-2)), T3 tarping, T4 tarping+quicklime (300 g m(-2)). The litter samples were collected on day zero and on the sixth and twelfth days after the start of fallowing. The use of quicklime alone or quicklime+tarping was more effective (P<0.05) in reducing bacteria when compared to litter tarping. Except for the control group, all treatments resulted in a more than 84% reduction in the count of colony-forming units (CFUs) at the end of fallowing. It is concluded that the use of quicklime alone in practical terms is the most indicated treatment for the reduction of the bacterial load of poultry litter.

Quicklime treatment and stirring of different poultry litter substrates for reducing pathogenic bacteria counts.

Testing different management practices can help to identify conditions that decrease or even eliminate pathogenic bacteria in poultry litter. A trial was conducted to evaluate the effects of daily manual stirring (rotation of the litter with a pitchfork) for the first 14 d of a bird's life (WDR), in 3 types of poultry litter substrates and quicklime treatment (CaO) during layout time between flocks on pathogenic bacteria occurrence (cfu). A total of 216 male Cobb broilers were randomly allotted to 18 pens with new litter (experimental unit). A split-plot design, with 6 treatments allotted to the main plots, was used: 1) wood shavings (WS) + WDR, 2) WS without stirring up to 14 d (WODR), 3) rice hulls (RIH) + WDR, 4) RIH + WODR, 5) mixture of 50% RIH and WS + WDR, and 6) mixture of 50% RIH and WS + WODR. Two treatments were allotted to the subplots: 0 and 300 g of CaO•m(-2) litter. After depopulation, litter samples were collected, and CaO was incorporated into the litter in the designated half of each pen. The cfu from litter samples after 7 d of the quicklime treatment were counted on Chapman agar, brain heart infusion media, and MacConkey agar. The data were analyzed using ANOVA, and the means were compared by least squares means (P < 0.05). Neither the type of substrate nor the act of stirring affected the cfu. The incorporation of 300 g of CaO•m(-2) litter efficiently reduced the cfu observed on brain heart infusion, Chapman agar, and MacConkey agar media by 57.2, 66.9, and 92.1%, respectively, compared with control (6.4, 17.9, and 46.1%; P < 0.001). In conclusion, the incorporation of 300 g/m(-2) of quicklime in poultry litter reduces the cfu, regardless of the substrate and stirring performed.