Effect of heating and aging of poultry litter on the persistence of enteric bacteria

Abstract

Food-borne illnesses have rarely been associated with the reuse of poultry litter as an organic fertilizer and soil amendment in agriculture. Yet farming practices in many countries have come under increased scrutiny because of heightened consumer awareness of food safety and environmental issues. This study was conducted to determine whether simple on-farm management practices could improve the microbiological safety of poultry litter. First, the effects of heat and moisture on the survival of Escherichia coli and Salmonella enterica serovar Typhimurium in poultry litter were investigated under laboratory conditions. Second, the persistence and regrowth of enteric bacteria were examined in poultry litter that had been aged for up to 12 wk in either a turned or static (unturned) windrow. Escherichia coli and Salmonella counts in poultry litter were reduced by >99% in 1 h at 55 or 65°C under laboratory conditions. At 35°C, both persisted longer under moist (65% wt/wt, wet basis) than dry (30% wt/wt) conditions. Poultry litter aged for 3 wk in a turned windrow, and up to 6 wk in a static windrow, supported increased E. coli densities when incubated in the laboratory at 37°C for 21 d. Peak temperatures >65°C were observed in both windrows within the first 3 wk of aging; after this point, the turned windrow was more consistently exposed to temperatures >45°C than the static windrow. By 12 wk, however, E. coli counts were very similar (3 to 3.6 log(10)) in the outside edge of both windrows. This study highlights the need for a better understanding of the interrelationship between spontaneous heating in organic waste streams, organic matter stabilization, and pathogen reduction.

DietaryArtemisia ordosicaextract alleviating immune stress in broilers exposed to lipopolysaccharide

“…There are many kinds of stress factors (environment, diseases, psychological factors and feeding management) in broiler breeding, which can directly or indirectly change the immune system, and induce the immune stress. (Mashaly et al 2004;Shini & Kaiser 2009;Wilkinson et al 2011) Previous studies showed that a number of different stressors result in the activation of the Hypothalamic-Pituitary-Adrenal axis (HPA axis) and the release of adrenocorticotropic hormone (ACTH), corticosterone (CORT) and the stressors can also act on immune system to influence organ growth, profiles of inflammatory cytokines and the immune response of antigen to antibody (Marketon & Glaser 2008;Shini & Kaiser 2009;Shini et al 2010). When under immune stress, animal body protein and fat anabolism will be weakened, while catabolism will be enhanced in order to satisfy the requirement of nutrients to synthesise immune effector molecules, and then animal will consume large amount nutrients, resulting in lower feed utilisation and decreased growth performance (Johnson 1997;Jacobi et al 2006).…”

Validating Thermal Inactivation of Salmonella spp. in Fresh and Aged Chicken Litter

“…High temperature is the most frequently studied mechanism involved in the inactivation of human pathogens during organic waste treatment processes (2,4,26,31,38). For example, Wilkinson et al (38) reported that Salmonella Typhimurium in fresh chicken litter containing rice hulls (30, 50, or 65% of moisture) was completely eliminated within 1 h in a water bath at both 55 and 65°C.…”

“…For example, Wilkinson et al (38) reported that Salmonella Typhimurium in fresh chicken litter containing rice hulls (30, 50, or 65% of moisture) was completely eliminated within 1 h in a water bath at both 55 and 65°C. Stringfellow et al (31) used pasteurization, with exposure to steam for 5, 30, or 120 min, to reduce Salmonella Typhimurium in chicken litter with pine shavings and found that Salmonella died off in chicken litter with 30 or 120 min of steaming, whereas a 3-log reduction was observed for 5 min of steaming.…”

Prevalence and resistance of bacterial strains isolated from chicken beddings in rural households

“…Consequently chickens can also be directly infected by water, feeds, rodents, flies and dust [9]. Poultry beddings are considered by some authors [10] as a hostile environment for the persistence of pathogens because it is dry, it has high ammonia content and it readily heats up. Research evidence suggests that bacterial counts decrease sufficiently when beddings are composted [11].…”