The discovery of novel Clostridium perfringens toxins NetB and TpeL has initiated questions regarding their role in the pathogenesis of disease. However, data showing the prevalence of these genes in C. perfringens populations are limited to certain geographical areas. If netB and tpeL are important virulence factors for disease worldwide, one would expect to find these genes in isolates from other regions as well. To address this hypothesis, C. perfringens isolates collected from Alabama broiler farms over 15 yr ago were toxin genotyped using PCR. Each isolate was screened for netB and tpeL; the major lethal toxin genes cpa, cpb, etx, and ia; and the enterotoxin gene cpe. Results of the assay showed all isolates presumed to be C. perfringens were genotypically type A, cpe negative except for one broiler litter isolate, which was genotypically type C. Only two isolates were positive for netB. Similarly, only two isolates were positive for tpeL, one of which was also netB positive. The low incidence observed for netB and tpeL indicates that these genes are not significant virulence factors for the sampled population.Baja Prevalencia de los genes netB y tpeL en aislamientos históricos de Clostridium perfringens de granjas de pollo de engorde en Alabama.El descubrimiento de las nuevas toxinas NetB y TpeL de Clostridium perfringens ha iniciado preguntas con respecto a su papel en la patogénesis de la enfermedad. Sin embargo, los datos muestran que la prevalencia de estos genes en las poblaciones de C. perfringens se limitan a ciertas áreas geográficas. Si netB y tpeL son factores importantes de virulencia de la enfermedad en todo el mundo, se esperaría encontrar estos genes en los aislamientos de otras regiones también. Para evaluar esta hipótesis, se genotipificaron mediante PCR, los genes que codifican las toxinas de aislamientos de C. perfringens que fueron recolectados hace más de quince años atrás de granjas de pollo de engorde de Alabama. Cada cepa se analizó para netB y tpeL; los genes principales de toxinas letales cpa, cpb, etx, e ia y el gene cpe de la enterotoxina. Los resultados del ensayo mostraron que todos los presuntos aislamientos de C. perfringens eran genotípicamente del tipo A, negativos para cpe, con excepción de un aislamiento de la cama de una parvada de pollo de engorde, que era genotípicamente del tipo C. Sólo dos aislamientos fueron positivos para netB. Del mismo modo, sólo dos aislamientos fueron positivos para tpeL, uno de los cuales también fue netB positivo. La baja incidencia observada para netB y tpeL indica que estos genes no son factores de virulencia importantes en la población muestreada.

Campylobacter is an important foodborne pathogen and is naturally found in chickens. During broiler production, litter can become contaminated with Campylobacter when birds defecate, and this litter, in some countries, is typically reused for the next flock, potentially causing cross-contamination. The goal of this experiment was to observe if reusing contaminated litter could spread Campylobacter between flocks and to observe if common litter treatments could prevent this cross-contamination. To determine this, a flock of birds was inoculated with Campylobacter jejuni and allowed to naturally contaminate the litter for 42 days. After grow-out, birds were terminated, and litter was given five treatments: uninoculated fresh litter, untreated re-used litter, composted re-used litter, re-used litter treated with sodium bisulfate (45 kg/305 m²), and re-used litter composted and treated with sodium bisulfate (45 kg/305 m²). A second flock was placed on the litter, grown for 42 days, and tested for C. jejuni prevalence. Following inoculation of the first flock, high prevalence of C. jejuni was observed; however, after a 19-day down-time between flocks, no C. jejuni was detected in any samples from the second flock. These results indicate that re-used litter was not a significant reservoir for cross-contamination of broilers when provided a significant down-time between flocks.

To the poultry industry, ammonia accumulation within poultry houses can be a costly issue, as this can lead to problems with bird performance, damage to economically important parts such as paws, and customer disapproval due to animal welfare concerns. Common management practices for ammonia control can be quite effective; however, these methods are used variably from farm to farm, which necessitates ammonia control measures that poultry companies can more uniformly implement across all contract growers. One possible measure is ammonia control through feed additives, which would allow poultry companies more direct control over the treatment. This project explored the efficacy of elemental sulfur added directly to the feed (feed-through sulfur) in controlling litter ammonia levels, live performance, and paw quality of broilers raised on built-up litter over three successive flocks. Feed-through sulfur on its own showed inconsistent effects on performance or footpad lesions after 38 days of production compared to sodium bisulfate or control treatments. However, combination of feed-through sulfur and sodium bisulfate showed a potential synergistic effect on ammonia levels and litter pH, although there were few differences between treatments and controls; therefore, additional research must be explored to confirm these observations.