A study was conducted to assess the effects of a dietary yeast cell wall (YCW) with and without a Campylobacter jejuni (CJ) challenge. A total of 2,240-day-old Ross 708 males were randomly assigned within 8 treatments with a 4 × 2 factorial design, with 4 diets (negative control, positive control, YCW constant dose (400 g/ton), and YCW step-down dose (800/400/200 g/ton in the starter/grower/finisher diets, respectively) and with and without d 21 CJ oral gavage challenge at 5.2 × 10⁷ CFU/mL. At d 0, 14, 28, and 41 body weights and feed consumption were measured to determine performance. At d 14, 28, and 42, 8 jejunal and ileal histology samples per treatment were collected for villi morphology measurements. At d 22 and 28 (1- and 7-days postinoculation), 24 ileal tissue samples per treatment were collected for relative gene expression analysis. At d 42, 24 cecal content samples per treatment were collected for CJ enumeration. Finally, on d 44, 96 birds per treatment were processed to determine carcass yield and 16 carcass rinses per treatment were collected to determine CJ prevalence after processing. Diet or inoculation did not impact broiler performance (P > 0.05). Limited differences were observed in intestinal morphology, and villus height and crypt depth were different only in the ileum at d 42 (P = 0.0280 and P = 0.0162, respectively). At d 1 postinoculation, differences between treatments inoculated with CJ and PBS were observed in the expression of avian beta defensin 10 (AvBD10), interleukin 1ß (IL-1ß), and interleukin 10 (IL-10) (P < 0.05). At d 7 postinoculation, expression of AvBD10, IL-1ß, and IL-10 was similar among all treatments (P > 0.05). At d 42, all birds, regardless the inoculation, had similar levels of CJ recovered from cecal contents (P > 0.05). After processing, carcass yield and CJ prevalence postchilling was similar in all treatments (P > 0.05). Overall, under the conditions of this study, the addition of YCW during a CJ challenge did not have an impact in growth performance, innate immune response, cecal colonization, carcass yield, or CJ prevalence after processing.

Some studies have shown that the NetB toxin may be an important virulence factor of Clostridium perfringens associated necrotic enteritis in poultry. Additionally, research has shown that strains of C. perfringens positive for both the netB gene and a second toxin-encoding gene, tpeL, appear to be more virulent than strains with only netB. In the past, detection of these genes has been performed relatively inefficiently using two single locus PCRs. This report describes a novel multiplex PCR developed to detect netB and tpeL simultaneously in C. perfringens strains isolated from cases of necrotic enteritis in broilers, providing a more efficient diagnostic tool in the screening of strains for these genes.

A successful hatch has a considerable economic impact on all poultry companies. The aim of the current study was to describe the possible effects of shell translucency (T score) and coloration lightness (L* value) on shell thickness, hatchability, and chick weight. A total of 4,320 eggs from 4 commercial Ross 708 breeder flocks (50-55-wk old) were used. Eggs were selected for T score and L* value. A 3-point subjective scoring system was used for T score (1 = low, 2 = medium, 3 = high), and an electronic colorimeter for L* value, sorting the eggs as light (avg. L* = 80.7) or dark (avg. L* = 76.0). Data were analyzed using the GLIMMIX procedure of SAS (V9.4) and Tukey's HSD test was performed to separate means, a significant difference was considered when P ≤ 0.05. Results suggest that the color of the eggshell was related to the egg weight on the day of collection (P = 0.0056) and at transfer (P = 0.0211), in both cases dark eggs were 0.6 g heavier than light eggs. Dark eggs had a 3.8% increased hatchability of egg set (P = 0.0481) and yielded 6 µm thicker shells (P = 0.0019) when compared to light eggs. Regarding translucency, egg weight at transfer was 0.8 g heavier for T score 1 eggs compared to T score 3 (P = 0.0358). The translucency score of 1 had a 6.9% higher hatchability of eggs set (P = 0.0127) and 0.7 g heavier chick weight (P = 0.0385) compared to T score 3. However, T score 1 eggs had shells 28 µm thinner than the T score 2 and 34 µm thinner than T score 3 (P < 0.0001). An interaction effect was observed for eggshell thickness, L* value, and T score, where eggs classified as light with T score 1 had thinner eggshells compared to those that were dark with T score 3 (P = 0.0292). These results suggest that eggshell translucency and coloration lightness can be good noninvasive indicators of eggshell thickness, hatchability, and chick weight in broiler breeder flocks.

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.

Antimicrobial resistance is a serious global public health concern that could endanger the efficacy of antibiotics used for the treatment of diseases in humans, animals, and plants. The objective of this study was to characterize the antimicrobial resistance (AMR) pattern of Salmonella strains isolated from different stages of both No-Antibiotics-Ever (NAE) and conventional integrated broiler complexes. ResFinder was used to identify AMR genes from whole genome sequences while the phenotypic resistance of 14 different antibiotics was determined using broth microdilution method. Odds ratio and 95 % confidence limits were calculated using multivariate logistic regression for different complexes and stages of broiler production (α = 0.05). The major AMR genes identified were aac(6')-Iaa, aph(6)-Id, aph(3″)-Ib, blaCARB-2, sul1, tet(A), tet(B), tet(G), floR, fosA7, gyrA, and parC. The phenotypic results showed that 58 % (49/85) of isolates were resistant to at least one antibiotic class (AOR), 24 % (20/85) of isolates were resistant to at least two or more classes of antibiotics (ATR) and 6 % (5/85) of isolates were multi-drug resistant (MDR). In terms of 14 different antibiotics tested, 41 %, 39 %, 6 %, 5 % and 2 % of isolates were resistant to sulfisoxazole, tetracycline, nalidixic acid, ampicillin and ciprofloxacin respectively. Interestingly, 80 % (32/40) of Kentucky isolates showed phenotypic resistance to either tetracycline or sulfisoxazole or both. In addition, the odds of ATR Salmonella detection were 7 times (1.37 - 43.45; 95 % CL) more likely in the isolates from NAE complex as compared to conventional broiler complex (p = 0.0233). Overall, drug-resistant Salmonella were present within and surroundings of poultry production and poultry product that could potentially contaminate the final raw product. It may lead to complicated antimicrobial therapy during foodborne infections in consumers.