In a warm climate, ventilation, indoor temperature and outdoor relative humidity have significant effects on Campylobacter spp. colonization in chicken broiler farms which can occur in only 2 days.

A longitudinal study was conducted in five conventional broiler farms during a 2-year period to determine the dynamics of Campylobacter infection in a warm climate region (north-eastern Spain). Weekly sampling of 63 flocks was performed upon one-day-old chick placement, including animal and environmental samples. Campylobacter spp. detection was assessed by culture and non-culture methods. Environmental samples were also obtained from cleaned and disinfected houses prior to chick placement. Thirty-nine flocks (61.90%) became colonized during the growing period. First bird excreting Campylobacter was detected in 10-day-old chicks and the earliest a whole flock became positive was at 14 days of age, while the latest was at 39 days. Once Campylobacter was detected in chickens, the whole flock was colonized within 2-13 days. Campylobacter farm prevalence (positive flocks) ranged from 53.85% to 83.33% in four out of five farms, while the remaining farm showed a lower prevalence (38.5%). Logistic regression model showed that Campylobacter infection was more likely under higher minimal indoor temperature as well as at higher minimal outdoor relative humidity, characteristic of warm climates such as those from Mediterranean countries. Ventilation type was also significant (P = 0.021). No clear farm effect or seasonality were observed. Biosecurity improvements, specially at house level, are needed in broiler farms to prevent flock colonization and reduce the current high flock prevalence.

Assessment of two different types of sample for the early detection and isolation of thermophilic Campylobacter in broiler farms.

In order to assess the optimal method for the early detection and isolation of thermophilic Campylobacter in broilers at farm level, two types of samples were compared: caecal contents obtained by necropsy and cloacal swabs transported in charcoal Amies medium. The study was conducted in five batches of broilers from five different farms, where weekly samples (caecal contents and cloacal swabs) from 30 birds were obtained. Samples were plated onto selective agar (modified charcoal cefoperazone desoxycholate agar, mCCDA) for Campylobacter isolation. Four out of five batches were positive for Campylobacter. No marked differences in sensitivity of both sample types were observed. However, a higher percentage of positive birds were detected when cloacal swabs were used. The results show that cloacal swab samples are adequate, and in some cases even better than caecal samples for the early detection of Campylobacter in broiler flocks at farm level. Also, this sample avoids sacrificing birds to test Campylobacter, which not only allows saving time in sample collection, transportation and processing at the laboratory, but also improves bird welfare and cost of sampling.

Efecto de la exclusión competitiva sobre la mortalidad e índices de producción de pollos de engorde / Effect of the competitive exclusion on mortality and productive performance in broilers chicken

El suministro de microflora gastrointestinal de un ave adulta sana a un pollito recién nacido ha demostrado acelerar la maduraciónde la microflora intestinal e incrementar la resistencia a la colonización por Salmonellas en los pollitos tratados. Este concepto conocido como Exclusión Competitiva (EC) está basado en el hecho de que esta flora intestinal madura excluye a ciertos patógenos entéricos, tales como Salmonella, de establecerse en el tracto digestivo. Para evaluar este principio a nivel de campo y su efecto sobre la mortalidad (M), el peso vivo (PV), el consumo de alimento (CA) y la conversión de alimento (CN), se evaluaron 3.500 pollitos de un día de edad (Avian Farm x Peterson) que fueron divididos en dos grupos: Grupo tratado (GT), el cual recibió en la incubadora un producto de EC (comercial, inespecífico en su composición y asociado a oligosacáridos de la manosa, elaborado de bacterias intestinales) y grupo control (GC), al cual no se le aplicó producto alguno. Al día 14 de edad de los pollos, se evaluó la incidencia del patógeno a través de hisopados cloacales, donde el porcentaje de animales infectados fue menor en el GT vs el GC (36 vs 64 por ciento). El efecto de EC sobre M, PV, CA y CN, fue analizado a través del paquete estadístico SAS. Los resultados mostraron que el porcentaje de M fue significativamente mayor (P < 0,05) para GT durante la primera semana de edad, observándose un incremento en el GT con relación al GC (2,11 vs 1,32 por ciento). Por otra parte, PV (0,440 vs 0,415 kg) y CA (42,16 vs 38,92 grs) fueron significativamente (P<0,05) mayor en el GT. La CN (1,072 vs 1,066) fue ligeramente mayor en el GT pero no resultó estadísticamente significativa. Lo evidenciado muestra que la EC resulta eficiente para disminuir la colonización por Salmonella a la vez que ayuda a mejorar los parámetros productivos.

It has been demonstrated that the administration from gastrointestinal microflora of a healthy adult bird to a new born chick accelerates the maturation of the intestinal microflora and increases the resistance to Salmonellas colonization in the treated chicks. This concept known as Competitive Exclusion (EC) based on the fact that this mature intestinal flora excludes certain enteric pathogens, such as Salmonella, from settling down in digestive tract. In order to evaluate this principle at the field level and its effect on mortality (M), body weight (PV), the feed consumption (CA) and the feed conversion rate (CN), 3,500 chicks one day of age (Avian Farm x Peterson) were evaluated. Chickens were divided in two groups: Treated group (GT), received in the hatchery a commercial EC product (with a unspecific composition, associated to oligosacáridos from manosa, elaborated of intestinal bacteria) and untreated control group (GC). At day 14th of age of the chickens, the incidence of Salmonella from cloacal swab was evaluated. The percentage of infected birds was reduced in the GT versus the GC (36% vs 64%) respectively. The effect of EC on M, PV, CA and CN, were analyzed with SAS. The results showed that the percentage of M was significantly increased (P < 0.05) in GT (2.11%) during the first week of age, compared to CG (1.32%). On the other hand, PV (0.440 vs 0.415 kg) and CA (42.16 versus 38.92 grs) were significantly (P < 0.05) greater in the GT compared to GC. The CN was slightly greater in the GT (1.072) versus GC (1.066) but not significant. In this study it was demonstrated that the CE was efficient to diminish the colonization of Salmonella, improving the productive parameters.