Presence of inoculated Campylobacter and Salmonella in unabsorbed yolks of male breeders raised as broilers.

Day-old male broiler breeder chicks were obtained from a commercial hatchery and raised as broilers. For Experiment 1, at 5 wk of age, the broilers were orally inoculated with a 10(6) cfu/ml of a characterized strain of Campylobacter jejuni and a cocktail (three naladixic acid-resistant strains) of Salmonella serovars. One week after inoculation, the birds were euthanatized and defeathered. The abdominal cavity was examined and any unabsorbed yolk material (and remaining yolk stalk) and ceca were aseptically removed for microbiological analyses. For each pooled sample (two birds per pool), an aerobic plate count (APC), an Enterobacteriaceae (ENT) count, and a test for the presence of Campylobacter and Salmonella was performed. For Experiment 2, at 5 wk of age, the broilers were orally inoculated with 10(5) cfu/ml of a characterized strain of Campylobacter jejuni. One week after inoculation, the birds (n = 20) were killed, defeathered, and the yolk stalk, attached yolk, or free-floating yolk and ceca were individually analyzed for presence of Campylobacter. For Experiment 1, the Salmonella-inoculated birds had 2/12 ceca and 0/12 unabsorbed yolk samples positive for Salmonella. The average yolk APC was log10 3.4 cfu/g and the average ENT was log10 1.9 cfu/g. For the Campylobacter-inoculated birds, 12/12 ceca and 9/12 unabsorbed yolk samples were positive for Campylobacter. The average yolk APC was log10 3.5 cfu/g and the average ENT was log10 3.1 cfu/g. For Experiment 2, the inoculated Campylobacter birds had 19/20 ceca, 5/20 free floating yolks, and 19/20 yolk stalks positive. In Experiment 1, the inoculated Campylobacter colonized the ceca in every instance and were present in 75% of the unabsorbed yolks. Alternatively, the inoculated Salmonella were not found in any of the unabsorbed yolks and only rarely in the ceca. In Experiment 2, the inoculated Campylobacter was found in very high numbers in the yolk and internal body samples. Determining to what extent these internal bodies and unabsorbed yolks play in bacterial colonization and contamination of the birds at processing has not been determined. The next step will be to determine the incidence of unabsorbed yolks and presence of Campylobacter and Salmonella in these bodies of commercial broilers at processing.

Prevalence of Clostridium perfringens in commercial broiler hatcheries.

Clostridium perfringens, a cause of human foodborne and poultry disease, has been isolated from the intestinal tract of poultry and from the processed carcass. Little is known about the incidence and sources of this pathogen in the poultry production environment. To determine if the broiler hatchery is a possible source of C. perfringens, we collected samples from three hatcheries, each operated by a different poultry integrator, and the presence of C. perfringens in these samples was determined. For each sampling period, eggshell fragments, chick fluff from the hatcher, and paper pads stored in the hatchery before use with chicks and after placement beneath chicks for 1 hr were evaluated. Clostridium perfringens was found in eggshell fragments, fluff, and paper pads in each of the three hatcheries. The percentages of C. perfringens-positive samples from the three hatcheries ranged from 13% to 23%, with an overall incidence of 20%. Positive samples were consistently found, i.e., detected on each of the nine sampling days (three sampling days for each of three hatcheries). These results suggest that the hatchery is a potential source/reservoir for C. perfringens in the integrated poultry operation.

Establishing a protocol to quantify leaflet fibroblast responses to physiologic flow through a viable heart valve.

Mechanical stresses are thought to affect the metabolism of a variety of cell types. Little quantitative data exist regarding heart valve leaflet fibroblast activity after dynamic loading. The goal of this study was to examine leaflet fibroblast function and differentiation in response to flow through an intact valve. This requires the development of a flow system capable of reproducing the valve's native environment, as well as assay protocols to analyze cellular viability and protein and collagen synthesis. As a tool to expose viable tissue valves to physiologic flow, a sterilizable pulsatile flow system has been developed to recreate the dynamic flow environment of the aortic valve while preventing contamination from room air. Physiologic flow conditions [frequency 70 bpm, aortic pressure 129/82 mmHg (systolic/diastolic), cardiac output 2.3 L/min] were sustained for 71 hr without microbiologic contamination. Analytic tools for assessment of fibroblast function include a viability assay, which demonstrated that leaflet viability decreases after prolonged exposure to antibiotics. Proline incorporation studies revealed that 11 times more protein is retained by leaflet tissue than is released into the medium, and 27% of this protein is collagen. Polyacrylamide gel electrophoresis clearly resolved collagen Types I and III from both prepared standards as well as leaflet extracts. In ongoing work, the sterile flow loop will be used to expose fresh porcine aortic valves to defined flow conditions, and the viability and protein/collagen biosynthetic activity of leaflet fibroblasts in response to flow will be quantified. These experiments will provide a baseline by which to design and evaluate future tissue engineered substitutes.

Applications of behavior to poultry management.

The application of poultry behavior to management is discussed with examples of behavior-management interactions relating to commercial poultry husbandry practices. Behaviors that are important for the adaptation of poultry to husbandry include: social behavior, aggression, sexual behavior, feeding, broodiness, cannibalism, nest site selection, and comfort behaviors.

Extent of salmonellae contamination in breeder hatcheries.

Egg fragments, paper pads from chick boxes, and fluff samples were obtained from six commercial broiler breeder hatcheries and analyzed for the presence and level of salmonellae. Overall, 42 of 380 samples (11.1%) from those hatcheries were contaminated with salmonellae. Salmonellae organisms were detected in 22 of 145 (15.2%), 5 of 100 (4.6%), and 15 of 125 (12%) samples of egg fragments, fluff, and paper pads, respectively. The percentage salmonellae-positive samples from each of the six hatcheries were 1.3, 5.0, 22.5, 11.4, 36.0, and 4.3% respectively. Of the 140 samples randomly selected for enumeration, salmonellae were found in 11 samples. Four of these 11 samples had greater than 10(3) salmonellae per sample, 3 others had greater than 10(2) but less than 10(3), and the remaining 4 had less than 10(2). Salmonella serotypes isolated were S. berta, S. california, S. give, S. hadar, S. mbandaka, S. senftenberg, and S. typhimurium, all of which have previously been isolated from poultry. The incidence and extent of salmonellae-positive samples found in the breeder hatcheries were much less than that previously found in broiler hatcheries. Many factors contribute to the lower incidence and level of salmonellae found in the breeder hatcheries; however both the breeder and broiler hatcheries present critical control points in the prevention of salmonellae contamination during commercial poultry production. The cycle of salmonellae contamination will not likely be broken until contamination at these critical points is eliminated.

Presence and impact of Salmonella contamination in commercial broiler hatcheries.

Egg fragments from hatching trays, swabs of belting material, and paper pads from three broiler hatcheries were sampled for the presence and level of salmonellae. Salmonella serotypes were recovered from 71, 80, and 74% of the egg fragments, belting material, and paper pads, respectively. Overall, salmonellae were found in 75, 91, and 67% of the samples taken at Hatchery 1,2, and 3, respectively. Thirty-eight of 40 randomly selected samples contained greater than 10(3) salmonellae cells per sample. All of the Salmonella serotypes encountered in the present study had previously been isolated from poultry. The presence and persistence of salmonellae contamination in the hatchery suggests that the vulnerable day-of-hatch chick may be at a greater colonization risk in the hatchery than during grow-out. Contamination and penetration of the shell of hatching eggs may constitute the most important link (or critical control point) in the transmission of salmonellae to young birds and eventually the consumer. An effective intervention method may have to be employed at this point to break the transmission link and significantly impact the overall problem of Salmonella colonization in poultry.

The relationship between the dwarfing gene and E. coli infection in two populations of chickens.

Resistance to an E. coli challenge was studied in the 6th, 7th, and 8th backcross generations after the introduction of the sex-linked recessive dwarf gene (dw) into two populations of White Plymouth Rock chickens that had undergone bidirectional selection for juvenile body weight. In the B6 and B8 generations, the dwarf genotype from the HW line had significantly higher mortality and/or heart lesions than the heterozygotes while the homozygous normal chickens were intermediate. No association between the dwarf allele and the incidence of E. coli infection was observed in the HW line in any generation, but genotypes in the LW lines were influenced by social environment in susceptibility to the E. coli challenge. Under low social strife, the dwarf and heterozygote genotypes were more susceptible than the normal genotype to the E. coli challenge, while under a high social strife there were no differences among genotypes. Since the genotypes in the LW line responded differently to the disease challenge than those in the HW line, it was concluded that a line-dwarf genotype interaction was present.

The behavior of chickens following embryonic treatment with testosterone propionate.

This study was designed to investigate an initial response and the flocking behavior of chicks treated embryonically with testosterone propionate (TP). The high (1.28 gm. %) and low (0.32 gm. %) levels of TP interfered with the response of these chicks to a specific stimulus. However, only the high level TP depressed the flocking response. TP administered prior to day 13 of embryonic development will depress sexual behavior in the chicken. These data suggest that TP influences a variety of behavioral patterns in the chicken.