Effect of trans-cinnamaldehyde nanoemulsion wash on chicken embryo development in fertilized eggs

Cleanliness of eggs is critical in successful hatching egg operations. The objective of this study was to investigate the effect of trans-cinnamaldehyde nanoemulsion (TCNE) wash treatments, as a sanitation strategy, on embryonic development in fertilized eggs. Trans-cinnamaldehyde is a generally recognized as safe status phytochemical obtained from cinnamon bark. TCNE were prepared with emulsifiers Tween 80 (Tw.80) or gum Arabic and lecithin (GAL) by sonication. Day-old fertilized eggs were subjected to TCNE wash treatments at 34°C for 5 min, followed by 18 d of incubation at 37.7°C. Washing of fertilized eggs with TCNE-Tw.80 or GAL at 0.48% concentration did not significantly alter the egg weight at d 18 of incubation, as compared to baseline and control (P > 0.05). The egg weight loss (calculated as percentage) did not differ significantly between eggs subjected to nanoemulsion wash treatments and control eggs (P > 0.05). In case of embryo fertility and mortality, for baseline and control, ∼ 95% fertility rate was achieved, with combined early and midterm mortality at 16%. Likewise, TCNE-Tw.80 or TCNE-GAL resulted in 95% fertility (P > 0.05), with 11% and 17% combined early and midterm mortality, respectively. Furthermore, TCNE wash treatments did not differ significantly in yolk sac and embryo weight (as compared to control) and did not affect the length of the d 18 embryo (P > 0.05). Moreover, TCNE wash treatments did not alter tibia weight and length (P > 0.05). Results suggest that TCNE could potentially be used as a natural antimicrobial for fertilized egg sanitation. Further studies in industry settings are warranted.

Trans-cinnamaldehyde nanoemulsion wash inactivates Salmonella Enteritidis on shelled eggs without affecting egg color

Salmonella Enteritidis is a major foodborne pathogen that causes enteric illnesses in humans, primarily through the consumption of contaminated poultry meat and eggs. Despite implementation of traditional disinfection approaches to reduce S. Enteritidis contamination, egg-borne outbreaks continue to occur, raising public health concerns and adversely affecting the popularity and profitability for the poultry industry. Generally Recognized as Safe (GRAS) status phytochemicals such as Trans-cinnamaldehyde (TC) have previously shown to exhibit anti-Salmonella efficacy, however, the low solubility of TC is a major hurdle in its adoption as an egg wash treatment. Therefore, the present study investigated the efficacy of Trans-cinnamaldehyde nanoemulsions (TCNE) prepared with emulsifiers Tween 80 (Tw.80) or Gum Arabic and lecithin (GAL) as dip treatments, at 34°C, for reducing S. Enteritidis on shelled eggs in presence or absence of 5% chicken litter. In addition, the efficacy of TCNE dip treatments in reducing trans-shell migration of S. Enteritidis across shell barrier was investigated. The effect of wash treatments on shell color were evaluated on d 0, 1, 7, and 14 of refrigerated storage. TCNE-Tw.80 or GAL treatments (0.06, 0.12, 0.24, 0.48%) were effective in inactivating S. Enteritidis by at least 2 to 2.5 log cfu/egg as early as 1 min of washing time (P < 0.05). In presence of organic matter, nanoemulsions (0.48%) reduced S. Enteritidis counts by ∼ 2 to 2.5 log cfu/egg as early as 1 min, (P < 0.05). Nanoemulsion wash also inhibited trans-shell migration of S. Enteritidis, as compared to control (P < 0.05). The nanoemulsion wash treatments did not affect shell color (P > 0.05). Results suggest that TCNE could potentially be used as an antimicrobial wash to reduce S. Enteritidis on shelled eggs, although further studies investigating the effect of TCNE wash treatments on organoleptic properties of eggs are necessary.

Carvacrol attenuates Campylobacter jejuni colonization factors and proteome critical for persistence in the chicken gut

Campylobacter jejuni is a major foodborne pathogen that causes gastroenteritis in humans. Chickens act as the reservoir host for C. jejuni, wherein the pathogen asymptomatically colonizes the ceca leading to contamination of carcasses during slaughter. The major colonization factors in C. jejuni include motility, intestinal epithelial attachment, acid/bile tolerance, and quorum sensing. Reducing the expression of the aforementioned factors could potentially reduce C. jejuni colonization in chickens. This study investigated the efficacy of subinhibitory concentration (SIC; compound concentration not inhibiting bacterial growth) of carvacrol in reducing the expression of C. jejuni colonization factors in vitro. Moreover, the effect of carvacrol on the expression of C. jejuni proteome was investigated using liquid chromatography-tandem mass spectrometry. The motility assay was conducted at 42°C, and the motility zone was measured after 24 h of incubation. For the adhesion assay, monolayers of primary chicken enterocytes (∼10⁵ cells/well) were inoculated with C. jejuni (6 log cfu/well) either in the presence or absence of carvacrol, and the adhered C. jejuni were enumerated after 90 min of incubation at 42°C. The effect of carvacrol on C. jejuni quorum sensing and susceptibility to acid/bile stress was investigated using a bioluminescence assay and an acid–bile survival assay, respectively. The SIC (0.002%) of carvacrol reduced the motility of C. jejuni strains S-8 and NCTC 81-176 by ∼50 and 35%, respectively (P < 0.05). Carvacrol inhibited C. jejuni S-8 and NCTC 81-176 adhesion to chicken enterocytes by ∼0.8 and 1.5 log cfu/mL, respectively (P < 0.05). Moreover, carvacrol reduced autoinducer-2 activity and increased the susceptibility of C. jejuni to acid and bile in both the strains (P < 0.05). Liquid chromatography-tandem mass spectrometry revealed that the SIC of carvacrol reduced the expression of selected C. jejuni colonization proteins critical for motility (methyl-accepting chemotaxis protein), adhesion (GroL), growth and metabolism (AspA, AcnB, Icd, Fba, Ppa, AnsA, Ldh, Eno, PurB-1), and anaerobic respiration (NapB, HydB, SdhA, NrfA) (P < 0.05). Results suggest the mechanisms by which carvacrol could reduce C. jejuni colonization in chickens.

Pectin or chitosan coating fortified with eugenol reduces Campylobacter jejuni on chicken wingettes and modulates expression of critical survival genes

Campylobacter jejuni infection in humans is strongly associated with the consumption of contaminated poultry products. With increasing consumer demand for minimally processed and natural product, there is a need for novel intervention strategies for controlling C. jejuni. Antimicrobial coatings are increasingly being used for preventing food contamination due to their efficacy and continuous protection of product. This study investigated the efficacy of pectin and chitosan coating fortified with eugenol to reduce C. jejuni on chicken wingettes. Pectin, chitosan, and eugenol are generally recognized as safe status compounds derived from berries, crustaceans, and cloves respectively. Each wingette was inoculated with a mixture of 4 wild-type strains of C. jejuni (approximately 10⁷ CFU/sample) and randomly assigned to controls, pectin (3%), chitosan (2%), eugenol (0.5, 1, or 2%), or their combinations. Following 1 min of coating, wingettes were air-dried, vacuum sealed, and sampled on 0, 1, 3, 5, and 7 d of refrigerated storage for C. jejuni and aerobic counts (n = 5 wingettes/treatment/d). In addition, the effect of treatments on wingette color and expression of C. jejuni survival/virulence genes was evaluated. All 3 doses of eugenol or chitosan significantly reduced C. jejuni and aerobic bacteria from 0 d through 7 d. Incorporation of 2% eugenol in chitosan improved coating efficiency and reduced C. jejuni counts by approximately 3 Log CFU/sample at the end of 7 d of storage (P < 0.05). Similarly, the antimicrobial efficacy of pectin was improved by 2% eugenol and the coating reduced C. jejuni by approximately 2 Log CFU/sample at 7 d of storage. Chitosan coating with 2% eugenol also showed greater reductions of total aerobic counts as compared to individual treatments of eugenol and chitosan. No significant difference in the color of chicken wingettes was observed between treatments. Exposure of C. jejuni to eugenol, chitosan, or combination significantly modulated select genes encoding for motility, quorum sensing, and stress response. Results demonstrate the potential of pectin or chitosan coating fortified with eugenol as a postharvest intervention against C. jejuni contamination on poultry products.

β-Resorcylic Acid, a Phytophenolic Compound, Reduces Campylobacter jejuni in Postharvest Poultry

Human Campylobacter infections, a leading foodborne illness globally, has been linked with the high prevalence of this bacterium on raw retail chicken products. Reduction of Campylobacter counts on poultry products would greatly reduce the risk of subsequent infections in humans. To this end, this study investigated the potential of the phytophenolic compound β-resorcylic acid (BR) to reduce Campylobacter counts on postharvest poultry (chicken skin or meat). Four trials in total, two each on thigh skin or breast meat, were conducted in which chicken skin or meat samples (2 ± 0.1 g; 10 samples per treatment) were inoculated with 50 μL (∼10⁶ CFU per sample) of a cocktail of four wild strains of C. jejuni. After 30 min of attachment, inoculated samples were dipped in a 0, 0.5, 1, or 2% BR solution for 30 s immediately followed by vigorously vortexing the samples in Butterfield's phosphate diluent and plating the supernatant for Campylobacter enumeration. In addition, the effect of BR on the color of skin and meat samples was studied. Moreover, the change in the expression of survival and virulence genes of C. jejuni exposed to BR was evaluated. Data were analyzed by the PROC MIXED procedure of SAS (P < 0.05; SAS Institute Inc., Cary, NC). All BR treatments significantly reduced Campylobacter populations on both chicken or meat samples by 1 to 3 log CFU/g compared with non-BR-treated washed controls. No significant difference in the lightness, redness, and yellowness of skin and meat samples was observed on exposure to BR wash (P > 0.05). Real-time PCR results revealed that BR treatment down-regulated expression of select genes coding for motility (motA, motB) and attachment (cadF, ciaB) in the majority of C. jejuni strains. Stress response genes (sodB, katA) were upregulated in C. jejuni S-8 (P < 0.05). Overall, our results suggest that BR could be effectively used as antimicrobial dip treatment during poultry processing for reducing Campylobacter on chicken carcasses.

Nutritional Supplement of Hatchery Eggshell Membrane Improves Poultry Performance and Provides Resistance against Endotoxin Stress

Eggshells are significant part of hatchery waste which consist of calcium carbonate crust, membranes, and proteins and peptides of embryonic origins along with other entrapped contaminants including microbes. We hypothesized that using this product as a nutritional additive in poultry diet may confer better immunity to the chickens in the paradigm of mammalian milk that enhances immunity. Therefore, we investigated the effect of hatchery eggshell membranes (HESM) as a short term feed supplement on growth performance and immunity of chickens under bacterial lipopolysaccharide (LPS) challenged condition. Three studies were conducted to find the effect of HESM supplement on post hatch chickens. In the first study, the chickens were fed either a control diet or diets containing 0.5% whey protein or HESM as supplement and evaluated at 5 weeks of age using growth, hematology, clinical chemistry, plasma immunoglobulins, and corticosterone as variables. The second and third studies were done to compare the effects of LPS on control and HESM fed birds at 5 weeks of age following at 4 and 24 h of treatment where the HESM was also sterilized with ethanol to deplete bacterial factors. HESM supplement caused weight gain in 2 experiments and decreased blood corticosterone concentrations. While LPS caused a significant loss in body weight at 24 h following its administration, the HESM supplemented birds showed significantly less body weight loss compared with the control fed birds. The WBC, heterophil/lymphocyte ratio, and the levels of IgG were low in chickens fed diets with HESM supplement compared with control diet group. LPS challenge increased the expression of pro-inflammatory cytokine gene IL-6 but the HESM fed birds showed its effect curtailed, also, which also, favored the up-regulation of anti-inflammatory genes compared with control diet fed chickens. Post hatch supplementation of HESM appears to improve performance, modulate immunity, and increase resistance of chickens to endotoxin.

Hearing conservation in the primary aluminium industry

Background

Noise-induced hearing loss has been an intractable problem for heavy industry.

Aims

To report our experience in reducing the incidence of age-corrected confirmed 10 dB hearing shifts (averaged over 2, 3 and 4kHz) in employees in the primary aluminium industry in Australia over the period 2006–13.

Methods

We analysed annual audiometric data to determine the number of permanent hearing shifts that occurred in employees in two bauxite mines, three alumina refineries and two aluminium smelters. Annual hearing shift rates were calculated based on the number of employees tested per year. Hearing conservation initiatives undertaken during the study period are described. An assessment of similar exposure group noise exposures was also undertaken to determine the magnitude of noise exposure reduction during the study period.

Results

Across all operations, hearing shift rates declined from 5.5% per year in 2006 to 1.3% per year in 2013 (P < 0.001). The decline in shift rates was greater in mines and refineries, where baseline shift rates were higher, than in smelter workers. Modest reductions in noise exposure occurred during the study period.

Conclusions

We observed a substantial decline in hearing shift rates during the study period. We describe the hearing conservation initiatives that were collectively associated with this decline. We suspect these initiatives could be deployed relatively easily and at modest cost in other industries with noise-exposed employees.

Intracloacal inoculation, an effective screening method for determining the efficacy of probiotic bacterial isolates against Campylobacter colonization in broiler chickens

Campylobacter is a leading cause of foodborne illness worldwide. It is common in poultry, and human infections are often associated with consumption of contaminated poultry products. One strategy to reduce Campylobacter colonization in poultry is the use of oral probiotics, but this produces variable results, possibly because the probiotics are destroyed in the stomach's acidic environment. Protection (e.g., encapsulation) of isolates may overcome this problem, but there is no assurance that these isolates will have efficacy in the lower gastrointestinal tract. Therefore, screening candidate isolates by directly placing them in the lower intestinal tract via cloacal inoculation may eliminate the time and expense of encapsulating ineffective isolates. Thus, the purpose of this study was to collect bacterial isolates with anti-Campylobacter activity in vitro and evaluate their efficacy in vivo upon either oral or intracloacal administration. Bacterial isolates were collected from healthy birds and were evaluated for efficacy against C. jejuni in vitro. Isolates having generally regarded as safe status and demonstrating in vitro anti-Campylobacter properties were evaluated after oral or intracloacal inoculation into chicks on day 1 (n = 10 birds per isolate per route of administration). On day 7, birds were dosed by oral gavage with a four-strain mixture of wild-type Campylobacter containing at least 1 × 10(7) CFU/ml organisms. On day 14, birds were euthanized and the ceca were collected aseptically for Campylobacter enumeration. When dosed orally, only one isolate had a 1-log reduction in cecal Campylobacter counts, whereas when administered intracloacally, six of these isolates produced a 1- to 3-log reduction in cecal Campylobacter counts in 14-day-old chickens. These results support the strategy of evaluating the efficacy of potential probiotic isolates via cloacal inoculation prior to undergoing the effort of encapsulating isolates for oral administration.

Use of plant-derived antimicrobials for improving the safety of poultry products

Salmonella Enteritidis and Campylobacter jejuni are the 2 major foodborne pathogens transmitted through poultry products. Chickens are the reservoir hosts of these pathogens, with their intestinal colonization being the most significant factor causing contamination of meat and eggs. Effective preslaughter strategies for reducing the colonization of birds with these pathogens are critical to improve the microbiological safety of poultry products. An antimicrobial treatment that can be applied through feed represents the most practical and economically viable method for adoption on farms. Additionally, a natural and safe antimicrobial will be better accepted by producers without concerns for toxicity. This symposium talk discussed the potential use of plant-derived, GRAS (generally recognized as safe)-status molecules, caprylic acid, trans-cinnamaldehyde, eugenol, carvacrol, and thymol as feed supplements for reducing cecal populations of Salmonella Enteritidis and C. jejuni in chickens. Additionally, the effect of plant molecules on Salmonella virulence genes critical for cecal colonization in chickens was also discussed.

Immune interference of bacteriophage efficacy when treating colibacillosis in poultry

A study was conducted to determine if prior exposure with bacteriophage would limit the ability of the same bacteriophage to treat colibacillosis. There were 5 treatments with 3 replicate pens of 20 birds per pen. The treatments consisted of 1) control, 2) birds treated with bacteriophage at 10 and 17 d of age, 3) birds challenged with Escherichia coli at 17 d of age, 4) birds challenged with E. coli and treated with bacteriophage at 17 d of age, and 5) birds treated with bacteriophage at 10 d of age and challenged with E. coli and treated with bacteriophage at 17 d of age. Colibacillosis was induced by injecting 0.1 mL of E. coli into the thoracic airsac containing 1 x 10(6) cfu. The bacteriophage was administered by i.m. injection of 0.1 mL into the thigh, providing a dose of 6.8 x 10(8) pfu. The study was concluded 14 d after E. coli challenge. Mortality in the birds challenged with E. coli and not treated with bacteriophage was 55% (treatment 3), and bacteriophage therapy significantly (P < or = 0.05) reduced mortality to 8% (treatment 4), which was not significantly (P < or = 0.05) different from the 2 non-E. coli-challenged controls (3%, treatment 1, and 2%, treatment 2). However, mortality in the birds administered bacteriophage before challenge with E. coli and treated with bacteriophage (treatment 5) was 33%, which was not significantly different (P < or = 0.05) from the birds that were challenged with E. coli and untreated (55%, treatment 3). A kinetic in vitro assay of bacteriophage activity found that serum from birds pretreated with bacteriophage (treatment 5) inhibited bacteriophage activity. The IgG levels to the bacteriophage in serum from birds pretreated with bacteriophage (treatment 2) were significantly higher at all dilutions compared with control serum (treatment 1). These data demonstrate that prior exposure to bacteriophage will limit bacteriophage therapeutic efficacy and suggests that the reduced efficacy is due to an immune response to bacteriophage.

Bacterial clearance, heterophil function, and hematological parameters of transport-stressed turkey poults supplemented with dietary yeast extract

Yeast extracts (YE) contain biological response modifiers that may be useful as alternatives to antibiotics for controlling pathogens in poultry production and mitigating the deleterious effects of production stressors. The objective of the present study was to determine the ability of a commercial dietary YE (Alphamune) to modulate the immune response in male turkey poults challenged with Escherichia coli and subjected to transport stress. Alphamune was added to turkey poult diets at 0, 500, or 1,000 g/ton. Poults were challenged by air sac injection with 60 cfu of E. coli at 1 wk of age. At 3 wk of age, these challenged birds were subjected to transport stress and birds were bled and necropsied the following morning. Blood cell numbers and percentages, hematological parameters, and clinical chemistry values were determined. Oxidative burst activity of isolated heterophils was measured using stimulation with phorbol myristate acetate and a 2',7'-dichlorofluorescein diacetate assay. Data were analyzed using GLM and least squares means procedures of the SAS program. The numbers and percentages of heterophils in peripheral blood were increased and their oxidative burst activity was stimulated by YE. The stress challenge dramatically increased oxidative burst and this increase was significantly modulated by YE treatment. Serum levels of calcium, phosphorus, and triglycerides were decreased and uric acid levels, erythrocyte numbers, hemoglobin, and hematocrit were increased by YE supplementation. Bacteria were isolated from the air sac and liver of a lower percentage of birds provided with YE. These results suggest that dietary YE has potential as a nonantibiotic alternative for decreasing bacterial pathogens in turkey production.

Gastrointestinal Maturation is Accelerated in Turkey Poults Supplemented with a Mannan-Oligosaccharide Yeast Extract (Alphamune)

Alphamune, a yeast extract antibiotic alternative, has been shown to stimulate the immune system, increase BW in pigs, and reduce Salmonella colonization in chickens. The influence of Alphamune on gastrointestinal tract development has not been reported. Two trials were conducted to evaluate the effects of Alphamune on gut maturation of 7- and 21-d-old turkey poults. Poults were fed a standard control unmedicated turkey starter diet or the same diet supplemented with either 1 or 2 lb/ton of Alphamune (n = 18/group). Poults were weighed on d 7 and 21, euthanized, and a 2-cm section was collected from the midpoint of the duodenum, jejunum, and ileum of each bird (9 poults/d per treatment) and fixed in a 10% formalin solution for 72 h and then stained. Twenty measurements of villus height, villus surface area, lamina propria thickness, crypt depth, and density of neutral, sialomucin, and sulfomucin goblet cells were taken per section per poult. On d 7, BW were higher for the poults given the Alphamune treatments compared with control poults; however, no differences were observed on d 21. Alphamune supplementation influenced intestinal morphology differently based on gut location. Ileum villus height, surface area, lamina propria thickness, crypt depth, and neutral, sialomucin, and sulfomucin goblet cell density were enhanced with Alphamune treatments on d 7 and 21 (P < 0.05) and in a dose-dependent manner for many of the parameters evaluated. Jejunum results were mixed. Surface area, crypt depth, and sialomucin and sulfomucin goblet cells were consistently higher for the 2 lb/ton of Alphamune groups compared with the control group on d 7 and 21. Duodenum villus height, surface area, and goblet cell density were higher for the 2 lb/ton of Alphamune groups on d 7; however, intestinal morphology of the duodenum was not different between the control and treated birds on d 21. These results suggest that feed supplemented with Alphamune can accelerate gastrointestinal maturation in turkey poults and is more pronounced in the ileum than in other portions of the small intestine.

Influence of Hen Age on the Response of Turkey Poults to Cold Stress, Escherichia coli Challenge, and Treatment with a Yeast Extract Antibiotic Alternative

Two battery experiments were conducted to evaluate a commercial yeast extract feed supplement, Alphamune, in a cold stress-Escherichia coli challenge of 1-wk-old turkeys. Experiment 1 used 1-d-old male poults that were the progeny of 33-wk-old hens in their second week of lay. Experiment 2 used male poults of the same genetic line from 40-wk-old hens in their eighth week of lay. Poults were fed a standard unmedicated turkey starter diet or the same diet with either a low level (504 g/t) or a high level (1,008 g/t) of yeast extract. Challenged birds were exposed to intermittent cold stress during wk 1 to 3 and to a respiratory E. coli challenge at 1 wk of age. In both experiments, BW at wk 1 was increased by feeding yeast extract. In experiment 1, challenged, control-fed birds had decreased BW at wk 3 and feed conversion was protected by both levels of yeast extract supplementation. In experiment 2, challenge had no effect on control-fed birds; however, yeast extract decreased the BW of challenged birds. In experiment 1, total leukocyte numbers were decreased by challenge of control-fed birds only, and there was no effect of challenge on the heterophil/lymphocyte ratio. In experiment 2, total leukocyte numbers were decreased and the heterophil/lymphocyte ratio was increased in challenged, control-fed birds. Percentage mortality was not affected by challenge in experiment 1; however, in experiment 2, mortality was increased by challenge of control-fed birds and those fed the lower level of yeast extract. These results suggest that hen age should be considered when designing studies to evaluate antibiotic alternatives and in making decisions for incorporating such alternatives into production.

Performance and Condemnation Rate Analysis of Commercial Turkey Flocks Treated with a Lactobacillus spp.-Based Probiotic

The use of defined probiotic cultures in the poultry industry has recently become more common. However, few conclusive studies regarding their efficacy under commercial conditions have been reported in the scientific literature. We conducted a study that included 118 commercial turkey hen lots, ranging from 1,542 to 30,390 hens per lot, of either Nicholas or Hybrid genetic lines, to look at the effect of a selected commercial Lactobacillus-based probiotic (FM-B11) on turkey BW, performance, and health. Sixty lots received the probiotic, whereas 58 lots were controls without probiotic. The probiotic was administered for 3 consecutive days at placement (day of age) and at move-out (around 6 wk of age, movement from brooder to grower houses). The parameters collected, calculated, and analyzed (significance level P < 0.05) were market BW, average daily weight gain, feed conversion ratio, and cost of production. There was no interaction effect between the genetic line and probiotic effect. Therefore, data from the 2 genetic lines were combined for the statistical analysis of the probiotic effect. The probiotic significantly improved market BW and average daily gain by 190 and 1.63 g, respectively. The feed conversion ratio was not statistically different between treatments (2.176 vs. 2.192 for the probiotic and control, respectively). However, the cost of production was lower in the probiotic-treated (58.37 cents/kg of live turkey) than in the control (59.90 cents/kg of live turkey) lots. Condemnation rates were not significantly different between lots. When each premise was compared by level of performance as good, fair, or poor (grouping based on historical analysis of 5 previous flocks), the probiotic appeared to increase the performance of the poor and fair farms. Use of the selected commercial probiotic resulted in increased market BW and reduced cost of production.

Effect of oral administration of bismuth compounds on Campylobacter colonization in broilers

Bismuth compounds have been used since the 18th century to treat gastrointestinal ailments in man. Colloidal bismuth subcitrate (De-Nol) is currently used in combination with antibiotics to reduce enteric Helicobacter pylori colonization as a treatment of stomach ulcers. We investigated whether bismuth citrate or its parent compound, colloidal bismuth subcitrate, would reduce colonization of the closely related foodborne pathogen, Campylobacter jejuni in chickens. In 2 studies, birds were either fed 0, 50, or 200 ppm bismuth citrate or bismuth subcitrate (De-Nol) for 10 or 21 d and were orally challenged with 7 combined strains of C. jejuni (n = 6 birds/treatment). For both treatment groups, cecal Campylobacter colonization was reduced when birds were fed 200 ppm for 10 d but not 21 d. For the 50 ppm treatment group, only birds dosed with bismuth citrate for 21 d demonstrated any reduction in cecal Campylobacter concentrations when compared with controls. These data suggest that bismuth citrate and colloidal bismuth subcitrate may reduce cecal colonization by Campylobacter in broilers, but these effects are inconsistent.

Upregulation of Oxidative Burst and Degranulation in Chicken Heterophils Stimulated with Probiotic Bacteria

The immune system of neonatal chicks is functionally immature during the first week of life. Researchers have previously demonstrated that the avian humoral response can be increased with probiotics. Although the humoral response provides the chick with an effective mechanism to combat pathogens, sufficient antibody titers are not attained until 7 to 10 d postinfection. However, the innate immune system (i.e., heterophils) can respond much more quickly to pathogens. The objective of this study was to determine whether probiotic bacteria can also upregulate heterophil function. Heterophils were isolated from the peripheral blood of neonatal chickens by using a discontinuous density gradient. Oxidative burst and degranulation are bactericidal mechanisms used by heterophils to kill pathogens and were used in this study as indicators of heterophil function. We found that each of the 10 "generally recognized as safe" probiotic isolates (designated G1 to G11) tested in vitro were capable of increasing (P < 0.05) heterophil oxidative burst and degranulation when compared with unstimulated controls. Bacillus subtilis (G3), Lactococcus lactis lactis (G6), and Lactobacillus acidophilus (G8) isolates were determined to elicit the greatest heterophil response in vitro and were subsequently fed to chicks. Phosphate-buffered saline or 1 of these 3 probiotic isolates (approximately 2.5 x 10(8) cfu/chick; 50 chicks/treatment) resuspended in PBS was administered by oral gavage on the day of hatch. Heterophils were isolated from chicks from each of these 4 treatment groups 24 h posttreatment. Significant increases in heterophil degranulation and oxidative burst were observed with the G3-, G6-, and G8-treated chicks when compared with heterophils isolated from birds with no probiotic treatment. These data suggest that probiotic bacteria can significantly improve heterophil oxidative burst and degranulation in broilers. To our knowledge, this is the first study demonstrating a relationship between probiotics and avian heterophil function.

Bacteriocins reduce Campylobacter colonization and alter gut morphology in turkey poults

Campylobacter is a leading cause of food-borne illness in the United States. Recent evidence has demonstrated that bacteriocins produced by Bacillus circulans and Paenibacillus polymyxa reduce cecal Campylobacter colonization in broiler chickens infected with Campylobacter jejuni. As Campylobacter coli is the most prevalent Campylobacter isolate recovered in turkeys, the objectives of the present study were to evaluate the efficacy of these bacteriocins against C. coli colonization and their influence on the gastrointestinal architecture of young turkeys. In 3 separate trials, a total of 135 day-of-hatch poults (n = 45/trial) were orally challenged on d 3 with approximately 10(6) cfu of a mixture of 3 C. coli isolates. Immediately before bacteriocin treatment (d 10), cecal Campylobacter concentrations averaged 1.1 x 10(7) cfu/ g of cecal contents (n = 15/trial). On d 10 to 12 posthatch, 2 bacteriocin treatment groups were given free access to feed supplemented with purified, microencapsulated bacteriocins, whereas the positive control treatment group had access to untreated feed (n = 10/treatment group per trial). At the end of the 3-d dosing period, ceca and duodenal loops were collected for analysis. In each of the 3 separate trials, treatment with bacteriocin eliminated detectable ceca Campylobacter concentrations (detection limit, 1 x 10(2) cfu/g of cecal contents) vs. controls (1.0 x 106 cfu of Campylobacter/g of cecal contents). Duodenum crypt depth and goblet cell numbers were also reduced in turkeys treated with either bacteriocin vs. controls (P < 0.05). The dynamic reduction in crypt depth and goblet cell density in turkeys dosed with bacteriocin may provide clues to how bacteriocins inhibit enteric Campylobacter.

Evaluation of the influence of bacteriophage titer on the treatment of colibacillosis in broiler chickens

Two studies were conducted to determine the efficacy of bacteriophage SPR02 and DAF6 at varying titers to treat colibacillosis in chickens. In Study 1, the treatments consisted of a control, i.m. injection of bacteriophage SPR02 or DAF6, Escherichia coli airsac challenge, and E. coli challenge followed by treatment at different titers with bacteriophage SPR02 or DAF6. The E. coli- challenged birds were injected with 6 x 10(4) cfu into the left thoracic airsac at 7 d of age. Immediately after the birds were challenged with E. coli, they were treated by administration of bacteriophage SPR02 or DAF6 by i.m. injection into the left thigh with 4 x 10(8), 10(6), 10(4), or 10(2) pfu. Study 2 was identical to Study 1, with the exception that the E. coli challenge was increased to 9 x 10(4) cfu, and the titers of SPR02 and DAF6 were slightly less at 3 x 10(8), 10(6), 10(4), and 10(2) pfu. Both studies were concluded when the birds were 3 wk of age. Mortality in the birds challenged with E. coli in Studies 1 and 2 was 48 and 47%, respectively. The only consistently effective bacteriophage treatment was the highest titer (10(8) pfu) of bacteriophage SPR02, which significantly reduced mortality from 48 and 47% in the birds only challenged with E. coli (positive control) to 7% in both studies, which was not significantly different from the unchallenged negative control treatments. These studies indicate that an effective multiplicity of infection for i.m. treatment with SPR02 was 10(4) in this experimental model of colibacillosis. Bacteriophage administered at sufficient titers can be effective therapeutic agents and provide an alternative to antibiotics in the treatment of bacterial diseases.

Efficacy of Iron Chelators on Campylobacter Concentrations in Turkey Semen

Campylobacter is a leading bacterial cause of human foodborne infections in the United States. Recent studies suggest that the organism is highly prevalent in poultry semen and may contribute to vertical transmission between the breeder hen and offspring. Because Campylobacter requires iron for its growth and survival, the objective of this study was to determine if the addition of natural and synthetic chelators such as ovotransferrin, desferrioxaime, EDTA, or 2,2'-dipyridyl could reduce or eliminate Campylobacter in turkey semen. In a preliminary study without semen, a commercial poultry semen extender was supplemented with various concentrations of ovotransferrin, desferrioxaime, EDTA, or 2,2'-dipyridyl and inoculated with an average of 10(8) cfu/mL of a wild-type Campylobacter coli turkey semen isolate. At 6 and 24 h of storage at 4 degrees C, a sample was taken from each treatment group and enumerated for Campylobacter. In all 3 trials, Campylobacter was undetectable (< 10(2)) in the commercial poultry semen extender supplemented with 20 mg/mL of 2,2'-dipyridyl. There were no differences observed in Campylobacter concentrations in the commercial poultry semen extender supplemented with ovotransferrin, desferrioxaime, or EDTA compared with unsupplemented controls. In a follow-up study, pooled semen samples were randomly collected from toms, diluted with a commercial poultry semen extender supplemented with 5, 10, or 20 mg/mL of 2,2'-dipyridyl and inoculated with an average of 10(8) cfu/mL of a wild-type C. coli turkey semen isolate. At 6 and 24 h of storage at 4 degrees C, samples were taken from each treatment group, enumerated for Campylobacter, and evaluated for sperm viability. In all 3 trials, supplementing the commercial poultry semen extender with 20 mg/mL of 2,2'-dipyryidyl significantly reduced (3 to 4 logs) Campylobacter concentrations when compared with the positive controls. Sperm viability was also reduced with this treatment, and, therefore, the use of 2,2'-dipyridyl may not be a practical treatment for reducing Campylobacter in poultry semen.

Campylobacter susceptibility to ciprofloxacin and corresponding fluoroquinolone concentrations within the gastrointestinal tracts of chickens

AIMS

This study evaluated the relationship between Campylobacter susceptibility and enteric fluoroquinolone concentrations in chickens treated with different doses of enrofloxacin.

METHODS AND RESULTS

All chickens were challenged with seven fluoroquinolone sensitive Campylobacter jejuni (6.6 x 10(6) CFU per bird) at 2 weeks posthatch. At 26 days of age chickens were treated with 0 (n = 29 birds), 25 mg ml(-1) enrofloxacin (Baytril, Bayer Corp., Shawnee Mission, KS, USA) for 3 days (n = 45 birds) or 50 mg ml(-1) enrofloxacin for 7 days (n = 65 birds) in the drinking water. The crop, upper ileum, lower ileum, ceca and colon contents were collected from both enrofloxacin treatment groups (n = 5 birds per day per treatment group) and nonmedicated controls. The minimum inhibitory concentration (MIC) of ciprofloxacin for Campylobacter increased for isolates from both treatment groups within the first day of dosing and the daily average ranged from 1.4 to 6.5 microg ml(-1) throughout the study. Although enteric fluoroquinolone concentrations were higher (P < 0.05) in birds dosed with 50 mg ml(-1)vs 25 mg ml(-1) enrofloxacin, there were no differences between the isolates collected from these groups for MIC values.

CONCLUSION

These data indicate, for the doses used, differences in gut fluoroquinolone concentrations do not produce isolates of Campylobacter with differing susceptibility to ciprofloxacin.

SIGNIFICANCE AND IMPACT OF THE STUDY

Using the manufacturers lowest, shortest duration dose vs the highest, longest duration dose of enrofloxacin did not change Campylobacter susceptibility to ciprofloxacin. However, ciprofloxacin MIC values for Campylobacter determined in this study were lower than previously reported.

Hypobaric hypoxia in ascites resistant and susceptible broiler genetic lines influences gut morphology

Genetic selection based on rapid growth rates, improved feed conversion, and increased body weights has led to a predisposition to ascites in broiler populations. Sire-family selection was applied to a commercial elite line to produce divergent lines of ascites-resistant (RES) and ascites-susceptible (SUS) broilers by the 8th generation. One objective of this research was to determine the effects of hypobaric hypoxia on gut morphology in these genetic lines. In two separate trials, pedigree broiler chickens were randomly assigned to cages in a hypobaric chamber (simulated 2,900 m above sea level) or a matching local altitude chamber (390 m above sea level). Ascites incidence was characterized by heart enlargement and fluid accumulation in the abdominal cavity. At the end of the study on d 42, all surviving birds were killed and evaluated for the presence of ascites and 2-cm sections from the duodenum and lower ileum were collected from 5 chickens per line, per altitude for each trial for morphometric analysis. At a high altitude, ascites incidence was lower in the RES line (20.9 and 3.7%) than in the SUS line (86.4 and 66.9%, Trials 1 and 2, respectively). No ascites was observed at a local altitude. Under hypoxic conditions, duodenum villus surface area was higher (P < 0.05) in the RES line (181.3 +/- 16.8 and 219 +/- 10.9 microm) compared with the SUS line (130.1 +/- 10.5 and 134.3 +/- 9.3 microm; Trials 1 and 2, respectively). No differences in ileum villus morphology were observed for any of the parameters measured. The reduced surface area in the duodenum of birds selected for ascites susceptibility suggests reduced enteric function and may provide clues as to why these birds have increased incidence of ascites.

Effect of prebiotic on gut development and ascites incidence of broilers reared in a hypoxic environment

Modern broilers have been genetically selected for an increased growth rate and improved feed conversion, but they are also more susceptible to ascites. Ascites occurs when there is an imbalance between available oxygen and the oxygen demand of the broiler. We hypothesized that promoting neonatal gut development with a prebiotic, such as Aspergillus meal (Prebiotic-AM), would enhance gut efficiency, decrease the oxygen demand of the gut, and reduce ascites incidence. In this study, we compared the effect of Prebiotic-AM on ascites incidence and gut development in commercial broilers reared at a local altitude (390 m above sea level) and a simulated high altitude (2,900 m above sea level). Half of the birds received a National Research Council recommended corn-soybean ration, and the other half received the same ration supplemented with 0.2% Prebiotic-AM. These 2 groups were further divided into a local altitude group and a simulated high altitude group for a total of 4 treatment combinations. Tissues were collected on d 1, 3, 7, 14, and 21 from the duodenum and lower ileum and placed in 10% buffered formalin for morphometric analysis. At a simulated high altitude, ascites incidence was 68% for birds fed the Prebiotic-AM supplement compared with 92% ascites incidence in birds given the control feed. The simulated high altitude decreased (P < 0.05) gut development, but prebiotic-treated birds reared in hypoxic conditions had similar gut development to control birds reared at local altitude. These data suggest that a feed ration supplemented with Prebiotic-AM may reduce the effect of hypoxia on broiler gut development and ascites incidence.

Use of a specific bacteriophage treatment to reduce Salmonella in poultry products

Bacteriophages represent a group of viruses that specifically infect and replicate in bacteria and could potentially be used to reduce recovery of Salmonella from poultry carcasses. Bacteriophages were isolated from municipal wastewater in the presence of Salmonella enteritidis phage type 13A (SE). In the first 2 experiments, commercially processed broiler carcass rinse water was pooled and divided. The addition of 10(10) pfu/mL of a single bacteriophage (PHL 4) with selected concentrations of SE reduced (P < 0.05) frequency of SE recovered as compared with the control rinse water sample. In experiments 3 and 4, broiler carcasses were intentionally inoculated with SE, sprayed with selected concentrations of PHL 4, and rinsed for SE enrichment and isolation. Application of 5.5 mL of 10(8) or 10(10) pfu/mL of PHL 4 reduced (P < 0.05) the frequency of SE recovery as compared with controls. In experiments 5 and 6, commercially processed turkeys were rinsed with water containing 72 wild-type bacteriophages isolated against SE, which were amplified in SE, or the Salmonella isolated antemortem from drag swabs from the flock selected for in-plant treatment, or a combination of bacteriophages amplified by each bacterial host. All bacteriophage treatments reduced (P < 0.05) frequency of Salmonella recovery as compared with controls. Sufficient concentrations of an appropriate bacteriophage, or a bacteriophage mixture, can significantly reduce recoverable Salmonella from carcass rinses.

Differential expression of cardiac muscle mitochondrial matrix proteins in broilers from ascites-resistant and susceptible lines

Ascites is a metabolic disorder of modern broilers that is distinguished by cardiopulmonary insufficiency in the face of intense oxygen demands of rapidly growing tissues. Broilers with ascites exhibit sustained elevation of pulmonary arterial pressure and right ventricular hypertrophy, the end result of which is heart failure. It has been shown that mitochondrial function is impaired in broilers with ascites. In the current study, mitochondrial matrix protein levels were compared between ascites-resistant line broilers and ascites-susceptible line broilers with and without ascites using two-dimensional (2-D) gel electrophoresis. One hundred seventy-two protein spots were detected on the gels, and 9 of the spots were present at different levels in the 4 groups of broilers. These 9 protein spots were selected for identification by mass spectrometry. Two of the spots were found to contain single mitochondrial matrix proteins. Both mitochondrial matrix proteins, the dihydrolipoamide succinyltransferase component of the 2-oxoglutarate dehydrogenase complex and the alpha-subunit of mitochondrial trifunctional enzyme, were present at higher levels in ascites-resistant line broilers with ascites in the present study. The elevated levels of 2 key proteins in aerobic metabolism in ascites-resistant line broilers with ascites observed in the present study suggests that the mitochondria of broilers with this disease may respond inappropriately to hypoxia.

Alternatives to antibiotics: utilization of bacteriophage to treat colibacillosis and prevent foodborne pathogens

Bacteriophages are viruses that infect and kill bacteria. Bacteriophage do not infect animal and plant cells, which makes them a potentially safe alternative to antibiotics. We have been conducting research on the efficacy of bacteriophage to prevent and treat colibacillosis in poultry. Bacteriophages that were lytic to a non-motile, serotype 02 isolate of Escherichia coli were isolated from municipal wastewater treatment plants and poultry processing plants. This E. coli isolate is pathogenic to poultry, causing severe respiratory and systemic infections. Two bacteriophage isolates were selected for use in studies designed to determine the efficacy of these bacteriophage to prevent and treat severe colibacillosis in poultry. Colibacillosis was induced by injecting 6 x 10(4) cfu of E. coli into the thoracic air sac when birds were 1 wk of age. Initial studies demonstrated that mortality was significantly reduced from 85 to 35% when the challenge culture was mixed with equal titers of bacteriophage, and the birds were completely protected when the challenge culture was mixed with 10 pfu of bacteriophage. In subsequent studies, we have shown that an aerosol spray of bacteriophage given to birds prior to this E. coli challenge could significantly reduce mortality even when given 3 d prior to the E. coli challenge. Our research on treating colibacillosis in poultry has demonstrated that an intramuscular injection of bacteriophage given 24 or 48 h after the birds were challenged rescued the birds from this severe E. coli infection. We have demonstrated that bacteriophage can be used to prevent and treat colibacillosis in poultry and may provide an effective alternative to antibiotic use in animal production.

Isolation and prevalence of Campylobacter in the reproductive tracts and semen of commercial turkeys

Campylobacter is one of the most commonly reported bacterial causes of human foodborne infections in the United States, and epidemiologic evidence indicates that a significant proportion of human infections result from the improper preparation of poultry products. Campylobacter frequently colonizes the avian intestinal tract, but recent research indicates that this organism can also colonize the avian reproductive tract and possibly contaminate eggs and subsequent offspring. The present studies were undertaken to determine the prevalence of Campylobacter in the reproductive systems of commercial turkeys. In the first study, pooled semen samples from seven commercial turkey farms were randomly collected by abdominal massage over a period of 13 wk. The pooled semen samples were serially diluted, and 0.1 ml of each dilution was plated on Campy-Line agar and incubated at 42 C for 48 hr in a microaerophilic environment for enumeration of Campylobacter. Campylobacter was isolated from 57 of the 59 pooled semen samples, and levels ranged from below the limit of detection (<10(1)) to 1.6 x 10(6) cfu/ml of semen. In the second study, the reproductive tracts of 11 hens and 17 toms were aseptically excised, and the segments (female: vagina, shell gland, isthmus, magnum, and infundibulum; male: ductus deferens and testes) were swabbed with a dry cotton sterile swab. The swabs were incubated for 24 hr in Campylobacter enrichment broth, and 0.1 ml of the enriched sample solution was streaked onto Campy-Line agar plates and incubated at 42 C for 48 hr in a microaerophilic environment. Of the 11 hens sampled, Campylobacter was isolated from the vagina (10/11), the shell gland (7/11), the isthmus (8/11), the magnum (6/11), and the infundibulum (4/11). Of the 17 toms sampled, Campylobacter was isolated from the ductus deferens (8/17) and the testes (2/17). Campylobacter is present in the reproductive tracts and semen of commercial turkeys and may lead to vertical transmission of Campylobacter from the hen to the chick.

Therapeutic efficacy of bacteriophage and Baytril (enrofloxacin) individually and in combination to treat colibacillosis in broilers

A study was conducted to evaluate the therapeutic efficacy of bacteriophage and the antibiotic enrofloxacin individually and in combination to treat colibacillosis. The experimental design was a 2 x 2 x 2 factorial with 8 treatments and 4 replicate pens of 10 birds. The treatments were 1) control, 2) unchallenged birds treated with bacteriophage, 3) enrofloxacin, or 4) the combination; 5) birds challenged with Escherichia coli, and birds challenged with E. coli and treated with 6) bacteriophage, 7) enrofloxacin, or 8) the combination of bacteriophage and enrofloxacin. Birds in the E. coli challenged treatments were challenged at 7 d of age by injecting 10(4) cfu of E. coli into the thoracic air sac. The antibiotic treatment was initiated immediately after the birds were challenged and consisted of 50 ppm enrofloxacin in the drinking water for 7 consecutive days. The bacteriophage treatment consisted of a single intramuscular injection of 2 different bacteriophage (10(9) pfu) administered immediately after the E. coli challenge. Mortality in the birds challenged with E. coli and untreated was 68%, and the bacteriophage and enrofloxacin treatments significantly decreased mortality to 15 and 3%, respectively. There was total protection in birds that received both the bacteriophage and enrofloxacin representing a significant synergy. The decrease in mortality with enrofloxacin (3%) was significantly better than the decrease in mortality with bacteriophage (15%). Airsacculitis lesion scores and lesion incidence in surviving birds were significantly less in the enrofloxacin treatment compared with the bacteriophage treatment. Both bacteriophage and enrofloxacin provided effective treatments of colibacillosis, and the synergy between these 2 treatments suggests that bacteriophage combined with antibiotic treatment has significant value.

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.

Detection of Campylobacter or Salmonella in Turkey Semen and the Ability of Poultry Semen Extenders to Reduce Their Concentrations

Campylobacter and Salmonella are the most commonly reported pathogens causing foodborne illness in the United States. In turkeys, the potential that semen used for artificial insemination is contaminated with these foodborne pathogens has not been investigated. Because semen on turkey farms is pooled and then used to inseminate multiple hens, contaminated semen could easily spread these bacteria throughout entire flocks via artificial insemination. The objectives of this study were to 1) determine if semen from commercial turkey farms contained these foodborne pathogens and 2) if present, evaluate the efficacy of semen extenders to reduce or eliminate Campylobacter and Salmonella from semen. Semen was collected from randomized pools of ejaculates from 10 to 30 toms per farm from 6 flocks over a 7-wk period and, on occasion, was found to contain Campylobacter, Salmonella, or both. To evaluate the efficacy of semen extenders to reduce or eliminate pathogens, pooled ejaculates were challenged with Campylobacter or Salmonella and treated with commercial poultry extenders containing various concentrations of antibiotics or an antibiotic combination previously demonstrated to remove Campylobacter from mammalian semen. Results demonstrate that commercial turkey semen may contain Campylobacter or Salmonella, and the semen extenders tested either did not reduce the bacteria or reduced but did not eliminate these bacteria from semen. We concluded that semen may be a potential vehicle for Campylobacter transfer to hens, and, if this is true, development of a method for eliminating pathogens in semen before insemination could reduce the risk of colonization.

Effects of Aeration and Storage Temperature on Campylobacter Concentrations in Poultry Semen

Campylobacter is one of the most commonly reported bacterial causes of human foodborne infections in the United States. Recent evidence has demonstrated that Campylobacter is present in poultry semen and may contribute to the vertical transmission between the breeder hen and offspring. As Campylobacter is considered sensitive to oxygen and cold temperature, the objective of this study was to determine if aeration and storage temperature could reduce or eliminate Campylobacter in poultry semen. In 4 separate trials, pooled semen samples were collected from roosters or toms, diluted with a commercial poultry semen extender, and inoculated with an average of 10(7) cells/mL of a wild-type C. jejuni or C. coli semen isolate. Pooled ejaculates were then divided into 3 aeration treatments: Control (no aeration), air, or oxygen (gently bubbled for 20 min with atmospheric air or oxygen, respectively). Immediately after aeration, pooled semen samples were further divided to 3 test storage temperatures: 4, 23, or 42 degrees C. At 0, 2, 6, and 24 h of storage, samples were enumerated for Campylobacter. Aeration of the semen alone, or aeration with reduced temperatures (4 or 23 degrees C), did not reduce the amount of Campylobacter compared with the controls. Campylobacter concentrations were, however, reduced when stored at 42 degrees C for 24 h. This effect is associated with reduced sperm viability and is therefore not a practical treatment of reducing Campylobacter in semen. It appears alternative methods will be needed to eliminate Campylobacter from poultry semen.

Differential expression of mitochondrial electron transport chain proteins in cardiac tissues of broilers from pulmonary hypertension syndrome-resistant and -susceptible lines

Pulmonary hypertension syndrome (PHS) is a metabolic disease associated with the rapid growth rate of modern broilers. Broilers susceptible to PHS experience sustained elevation of pulmonary arterial pressure leading to right ventricular hypertrophy and ultimately heart failure. Previous studies have shown that mitochondrial function is defective in broilers with PHS; they use oxygen less efficiently than broilers without PHS. In this study mitochondrial electron transport chain (ETC) protein levels were compared in cardiac tissues from PHS resistant and susceptible line broilers using quantitative immunoblots. Seven of 9 anti-mammalian mitochondrial ETC protein antibodies tested exhibited cross-species reactivity. Six ETC proteins were differentially expressed in the right ventricles of broilers raised under simulated high altitude conditions (2,900 m above sea level). Four ETC proteins were present at higher levels in resistant line birds without PHS than in resistant line birds with PHS or in susceptible line birds with or without PHS. One ETC protein was present at higher levels in broilers without PHS than in broilers with PHS in both lines, and one ETC protein was present at lower levels in susceptible line birds without PHS than in susceptible line birds with PHS or in resistant line birds with or without PHS. Interestingly, differential expression of mitochondrial ETC proteins was not observed in the right ventricles of broilers raised at local altitude (390 m above sea level) nor was it observed in the left ventricles of broilers exposed to simulated high altitude. These results suggest that higher levels of mitochondrial ETC proteins in right ventricle cardiac muscle may be correlated with resistance to PHS in broilers.

Bacteriophage treatment of a severe Escherichia coli respiratory infection in broiler chickens

A bacteriophage to a serotype 02, nonmotile Escherichia coli was isolated from municipal waste treatment facilities and poultry processing plants. A study was conducted to determine the efficacy of multiple vs. single intramuscular (i.m.) injections of bacteriophage to treat a severe E. coli respiratory infection. The birds were challenged at 7 days of age by injection of 6 x 10(4) colony-forming units (cfu) of E. coli into the thoracic air sac followed by an i.m. injection into the thigh with either heat-killed or active bacteriophage. There were 16 treatments with three replicate pens of 10 birds. There were four control treatments, which included untreated birds, birds injected with either heat-killed or active bacteriophage, and birds challenged only with E. coli. In the remaining treatments, birds were injected with heat-killed or active bacteriophage either once immediately after E. coli challenge or immediately after challenge and at 8 and 9 days of age, once at 8 days of age or at 8, 9, and 10 days of age, and once at 9 days of age or at 9, 10, and 11 days of age. Mortality was significantly decreased from 57% to 13% in the birds given a single i.m. injection of bacteriophage immediately after E. coli challenge, and there was complete recovery in birds treated immediately after challenge and at 8 and 9 days of age, which was a significant improvement from the single injection treatment. There was a significant reduction in mortality from 57% to 10% in the birds treated with bacteriophage once at 8 days of age and those birds treated at 8, 9, and 10 days of age, with no difference between single or multiple treatments. The mortality in the single or multiple phage treated birds that started at 9 days of age was reduced from 57% to 28% and 27%, respectively, but was not statistically different from the control. These data suggest that bacteriophage can be an effective treatment when administered early in this experimental E. coli respiratory disease and that early multiple treatments are better than a single treatment. The efficacy of bacteriophage treatment diminishes as it is delayed, with no difference between single or multiple treatments. Bacteriophage may provide an effective alternative to antibiotics, but like and biotic therapy, the effectiveness of phage to rescue animals decreases the longer treatment is delayed in the disease process.

Sequence analysis of bone morphogenetic protein receptor type II mRNA from ascitic and nonascitic commercial broilers

Ascites syndrome, also known as pulmonary hypertension syndrome (PHS), is a common metabolic disorder in rapidly growing meat-type chickens. Environmental factors, such as cold, altitude, and diet, play significant roles in development of the disease, but there is also an important genetic component to PHS susceptibility. The human disease familial primary pulmonary hypertension (FPPH) is similar to PHS in broilers both genetically and physiologically. Several recent studies have shown that mutations in the bone morphogenetic protein receptor type II (BMPR2) gene are a cause of FPPH in humans. To determine whether mutations in the chicken BMPR2 gene play a similar role in PHS susceptibility, BMPR-II mRNA from ascitic and nonascitic commercial broilers were sequenced and compared with the published Leghorn chicken BMPR-II mRNA sequence. Fourteen single nucleotide polymorphisms (SNP) were identified in the commercial broiler BMPR-II mRNA. No mutations unique to ascites-susceptible broilers were present in the coding, 5' untranslated or 3' untranslated regions of BMPR-II mRNA. The twelve SNP present within the coding region of BMPR-II mRNA were synonymous substitutions and did not alter the BMPR-II protein sequence. In addition, analysis of BMPR2 gene expression by reverse transcriptase-PCR indicated that there were no differences in BMPR-II mRNA levels in ascitic and nonascitic birds. Therefore, it appears unlikely that mutations in the BMPR2 gene were responsible for susceptibility to PHS in these commercial broilers.

Approach for selection of individual enteric bacteria for competitive exclusion in turkey poults

The intentional early colonization of the intestinal tract with beneficial microflora, known as competitive exclusion, has been shown to successfully protect poultry from selected enteric pathogens. Although effective cultures have been produced and are available, an inexpensive, air-tolerant, and completely defined culture is needed. Presently, we developed an in vitro competition assay to select for individual facultative anaerobes of poultry enteric origin that could exclude Salmonella. Using this assay, 24 isolates were selected and stored individually. These 24 isolates were amplified in batch culture (tryptic soy broth, 4 h at 40 degrees C) and administered at final dilutions of 10, 100, or 1,000 cfu to day-of-hatch poults. Forty-eight hours later, poults were challenged with 100 to 1,000 cfu antibiotic-resistance-marked Salmonella enteritidis PT 13A by oral gavage. Five days later, all poults were killed, and cecal tonsils were aseptically removed for tetrathionate enrichment (24 h at 37 degrees C) followed by selective plating with marker antibiotics. Selected lactose-negative, antibiotic-resistant colonies typical of Salmonella were further confirmed by serogrouping. Treatment-related protection ranged from 0 to 100% in three experiments. Greatest protection was related to the lowest concentrations of the protective microflora in each experiment. These data suggest that effective combinations of competitive enteric microflora can be identified by appropriate in vitro selection methods.

Field testing the influence of sperm competition based on sperm mobility in breeder turkey toms

1. Commercial reproduction of turkeys relies on pooling of semen from multiple males for inseminations. Understanding how sperm characteristics influence paternity under commercial breeding conditions is important to improving production efficiency. 2. The objective of this study was to evaluate progeny production of individual toms following commercial practices of pooling semen to determine if sperm mobility influences progeny production in field conditions. 3. A total of 104 toms were evaluated for sperm mobility. A subset of 10 toms were housed together and semen was collected, pooled and used to inseminate hens (n = 28). Hens were inseminated at 30 weeks of age and weekly thereafter. 4. Ejaculates from each tom were evaluated on two separate days for sperm mobility. Semen from each tom was diluted and layered upon 6% (wt/vol) Accudenz solution. The sperm suspension was incubated at 41 degrees C for 5 min and absorbance was measured with a spectrophotometer. 5. Toms were ranked by absorbance and categorised as high or low if mobility score was +/- 1 SD from the flock mean (average). 6. For parentage determination, DNA was extracted from tom, hen and poult blood. Poult parentage (n = 276) was determined at one day of age or at 14 weeks by analysis of marker genotypes that were generated by polymerase chain reaction (PCR) amplification of genomic DNA with selected microsatellite markers. 7. Sperm mobility differed across males with absorbance values ranging from 0.147 to 0.366. 8. Findings demonstrate differences in poult production among individual toms when semen from multiple males was pooled and inseminated. Toms classified as high, average and low produced 55, 41 and 4% of the offspring, respectively. 9. It appears that sperm mobility is a trait that influences sperm competition among toms under field conditions where sperm numbers inseminated from individual toms are not controlled or constant and that toms with low sperm mobility produce few offspring.

Evaluation of aerosol spray and intramuscular injection of bacteriophage to treat an Escherichia coli respiratory infection

Two studies were conducted to determine the efficacy of either aerosol or i.m. injection of bacteriophage to treat an Escherichia coli respiratory infection in broiler chickens. An additional two studies were conducted to enumerate the bacteriophage in the blood of birds at 1, 2, 3, 4, 5, 6, 24, and 48 h after being sprayed or injected i.m. with bacteriophage. Five birds were bled at each period. In study 1, there were 10 treatments with three replicate pens of 10 birds. The treatments consisted of an untreated control, heat-killed bacteriophage spray, active bacteriophage spray, E. coli challenge at 7 d of age, and E. coli challenge followed by spraying the birds with heat-killed bacteriophage or active bacteriophage at 2, 24, or 48 h after challenge. In study 2 there were 11 treatments with three replicate pens of 10 birds per pen. The treatments were untreated controls, birds injected i.m. in the thigh with heat-killed or active bacteriophage, E. coli challenge at 7 d of age, PBS challenge, E. coli challenge followed by injection of heat-killed or active bacteriophage immediately after challenge or at 24 or 48 h after challenge. In both studies the E. coli challenge consisted of injecting 10(4) cfu into the thoracic air sac. Treatment of this severe E. coli infection with the bacteriophage aerosol spray significantly reduced mortality from 50 to 20% when given immediately after the challenge but had little treatment efficacy when administered 24 or 48 h after challenge. The i.m. injection of bacteriophage significantly reduced mortality from 53 to 17%, 46 to 10%, and 44 to 20% when given immediately, 24, or 48 h after challenge, respectively. Only a few birds sprayed with bacteriophage had detectable bacteriophage in their blood with an average of 96 pfu/mL 1 h after bacteriophage administration, and no bacteriophage was detected 24 and 48 h after bacteriophage administration. All birds injected i.m. with bacteriophage had detectable levels of bacteriophage in their blood at levels of 10(4) pfu/mL of blood up to 6 h after bacteriophage administration, and four of the five birds had detectable bacteriophage in their blood at an average level of 70 pfu/mL of blood 24 h after bacteriophage administration. The relative inefficiency of the spray treatment to the i.m. injection treatment may be due to the inability to get bacteriophage into the blood at high concentrations when the birds are sprayed versus the consistent high titers achieved with the i.m. injection of bacteriophage. These data provide support to the concept that bacteriophage may be an effective alternative to antibiotics in animal production when they are administered in a way that delivers high titers of the bacteriophage to the critical site of the bacterial infection.

Type A lactic acidosis in occupational heat exhaustion

BACKGROUND

This paper presents a further analysis of biochemical data collected during a 1 year prospective study of 106 cases of heat exhaustion at a deep underground metalliferous mine.

RESULTS

Multiple regression analysis results indicate that the haemoglobin, serum creatinine and plasma lactate concentrations are statistically significant predictors of the anion gap. Together, they explain 65% of the variance in the anion gap (R(2) = 0.650). Spearman's rho correlation results also confirm that haemoglobin, creatinine and lactate are each statistically significantly correlated with the anion gap (P < 0.001).

CONCLUSIONS

These results indicate that dehydration and lactate are important determinants of the metabolic acidosis previously observed in occupational heat exhaustion. It is likely that dehydration in these workers has resulted in poor muscle perfusion, anaerobic conditions and elevated lactate. This constitutes Type A lactic acidosis. Creatine kinase is not a statistically significant predictor of the anion gap in multiple regression (P = 0.956). Furthermore, the Spearman's rho correlation coefficient for creatine kinase versus the anion gap is weak (r(s) = 0.175) and is not statistically significant (P = 0.073). These results suggest that there was no rhabdomyolysis contributing to the metabolic acidosis.

Prevention of Escherichia coli infection in broiler chickens with a bacteriophage aerosol spray

Bacteriophage to an Escherichia coli isolate that is pathogenic in poultry were isolated from municipal sewer treatment facilities or poultry processing plants. Three studies were conducted to determine the efficacy of aerosol administration of bacteriophage to prevent an E. coli respiratory infection in broiler chickens. In all three studies the experimental design consisted of nine treatments with three replicate pens of 10 birds. Three treatments were not challenged with E. coli and consisted of unsprayed birds, birds sprayed with a diluent control, and birds sprayed with a combination of two bacteriophages. Six treatments were challenged with E. coli by injecting 10(4) cfu into the thoracic air sac when birds were 7, 8, or 10 d of age after being sprayed at 7 d of age with either a diluent control or a combination of two bacteriophages. In Studies 1 and 2, BW at 2 wk of age of all the birds challenged with E. coli, regardless of spray treatment, were decreased significantly from the unchallenged controls, except in Study 2 for the birds sprayed with bacteriophage and challenged at 10 d of age. There was a significant decrease in mortality in Studies 1 and 2 when the birds were challenged with E. coli immediately after bacteriophage administration and in Study 2 in birds challenged at 10 d of age. In Study 3 a suspected pre-existing E. coli infection resulted in mortality in the unchallenged, unsprayed controls, and in the diluent sprayed controls of 20 and 27%, respectively. The mortality in the unchallenged bacteriophage sprayed birds was 3%, representing a significant decrease. Mortality in Study 3 was significantly decreased in the bacteriophage-sprayed birds challenged with E. coli immediately or 1 d later but not 3 d after bacteriophage administration. The decrease in BW at 2 wk of age in challenged birds indicates that bacteriophage treatment did not provide complete protection; however, in all three studies mortality was significantly decreased, indicating that aerosol spray of bacteriophage may be practical for administration of bacteriophage and may provide an alternative to the use of antibiotics in poultry production.

Coal dust exposures in the longwall mines of New South Wales, Australia: a respiratory risk assessment

This paper presents an analysis of personal respirable coal dust measurements recorded by the Joint Coal Board in the underground longwall mines of New South Wales from 1985 to 1999. A description of the longwall mining process is given. In the study, 11 829 measurements from 33 mines were analysed and the results given for each occupation, for seven occupational groups, for individual de-identified mines and for each year of study. The mean respirable coal dust concentration for all jobs was 1.51 mg/m(3) (SD 1.08 mg/m(3)). Only 6.9% of the measurements exceeded the Australian exposure standard of 3 mg/m(3). Published exposure-response relationships were used to predict the prevalence of progressive massive fibrosis and the mean loss of FEV(1), after a working lifetime (40 years) of exposure to the mean observed concentration of 1.5 mg/m(3). Prevalences of 1.3 and 2.9% were predicted, based on data from the UK and the USA, respectively. The mean loss of FEV(1) was estimated to be 73.7 ml.

Prevention of Escherichia coli respiratory infection in broiler chickens with bacteriophage (SPR02)

Bacteriophages are viruses that can infect and kill bacteria. Three studies were conducted to determine the efficacy of bacteriophage to prevent an Escherichia coli respiratory infection in broiler chickens. In the first study 3-d-old-birds were challenged with an air sac inoculation of 10(3) cfu of E. coli per mL mixed with either 10(3) or 10(6) pfu of bacteriophage, or 10(4) cfu E. coli mixed with 10(4) or 10(8) pfu of bacteriophage. In the second study, drinking water of birds to 1 wk of age was treated with 10(3) or 10(4) pfu of bacteriophage per mL and birds were air sac challenged with 10(3) cfu of E. coli, or water was treated with 10(4) or 10(6) pfu of bacteriophage per milliliter and birds were challenged with 10(4) cfu of E. coli. In the third study, birds were air sac challenged at 1 wk of age with 10(4) cfu of E. coli and given 10(5) or 10(6) pfu of bacteriophage per mL of water from 1 d of age to 2 wk of age. In Studies 1 and 2, there were two replicate pens per treatment with 10 birds per pen, and in Study 3, there were four replicate pens per treatment with 10 birds per pen. The studies were all concluded when the birds were 3 wk of age. In Study 1, BW was decreased at 1 and 2 wk of age in the birds that were challenged with 10(3) or 10(4) cfu of E. coli and was decreased at 2 wk of age in the birds challenged with 10(4) cfu of E. coli mixed with 10(4) pfu of the bacteriophage. Mortality was decreased from 80% in the birds challenged with 10(3) cfu of E. coli to 25 and 5% when mixed with 10(3) or 10(6) pfu of the bacteriophage, respectively. Mortality was decreased from 85% in birds challenged with 10(4) cfu of E. coli to 35% when mixed with 10(4) pfu of the bacteriophage, and no mortality occurred when mixed with 10(8) pfu of bacteriophage. There was essentially no protection observed in Studies 2 and 3 when the birds were challenged with 10(3) or 10(4) cfu of E. coli with bacteriophage present in their drinking water at any level. These data suggest that bacteriophage can protect birds from a respiratory challenge with E. coli, but that adding the bacteriophage to the drinking water offered no protection to the birds. The complete protection of the birds observed in Study 1 suggests that bacteriophage may possibly be developed as an alternative to antibiotic use in poultry.

Segregation of spermatozoa within sperm storage tubules of fowl and turkey hens

In avian species, spermatozoa reside in the oviduct for prolonged periods in specialized structures known as sperm storage tubules, but little is known about the relative distribution of spermatozoa in these tubules after successive inseminations by different males. The staining efficacies of various fluorescent dyes for fowl and turkey spermatozoa were evaluated to investigate one proposed mechanism of sperm competition. Hens were then inseminated at different intervals with stained and unstained spermatozoa to observe the spatial distribution of spermatozoa within the storage tubules. Several novel fluorescent lipophilic tracers that successfully stain mammalian spermatozoa either did not stain fowl or turkey spermatozoa, or greatly impaired sperm motility. In contrast, Hoechst 33342 readily stained sperm nuclei (fowl: 25 nmol l-1; turkey: 77 nmol l-1) within 4 h without inhibiting sperm motility, or affecting fertility or the hatching ability of the eggs. Hens were tandemly inseminated with equal numbers of stained or unstained spermatozoa at 24 h intervals and were killed 24 h after the final insemination to study sperm entry and storage within the tubules. Oviductal mucosa containing sperm storage tubules was removed, and individual tubules were classified as containing stained spermatozoa, unstained spermatozoa, a mixture of stained and unstained spermatozoa, or as not containing spermatozoa. Results from the present study indicate that spermatozoa from two different inseminations generally segregate into different storage tubules in both fowl and turkey hens. Storage tubules containing mixed populations of spermatozoa were found in only 4% of fowl and 12% of turkey storage tubules examined. Thus, the mechanism of last-male precedence does not appear to be due to the stratification of spermatozoa within the tubules.

Segregation of spermatozoa within sperm storage tubules of fowl and turkey hens

In avian species, spermatozoa reside in the oviduct for prolonged periods in specialized structures known as sperm storage tubules, but little is known about the relative distribution of spermatozoa in these tubules after successive inseminations by different males. The staining efficacies of various fluorescent dyes for fowl and turkey spermatozoa were evaluated to investigate one proposed mechanism of sperm competition. Hens were then inseminated at different intervals with stained and unstained spermatozoa to observe the spatial distribution of spermatozoa within the storage tubules. Several novel fluorescent lipophilic tracers that successfully stain mammalian spermatozoa either did not stain fowl or turkey spermatozoa, or greatly impaired sperm motility. In contrast, Hoechst 33342 readily stained sperm nuclei (fowl: 25 nmol l-1; turkey: 77 nmol l-1) within 4 h without inhibiting sperm motility, or affecting fertility or the hatching ability of the eggs. Hens were tandemly inseminated with equal numbers of stained or unstained spermatozoa at 24 h intervals and were killed 24 h after the final insemination to study sperm entry and storage within the tubules. Oviductal mucosa containing sperm storage tubules was removed, and individual tubules were classified as containing stained spermatozoa, unstained spermatozoa, a mixture of stained and unstained spermatozoa, or as not containing spermatozoa. Results from the present study indicate that spermatozoa from two different inseminations generally segregate into different storage tubules in both fowl and turkey hens. Storage tubules containing mixed populations of spermatozoa were found in only 4% of fowl and 12% of turkey storage tubules examined. Thus, the mechanism of last-male precedence does not appear to be due to the stratification of spermatozoa within the tubules.

A risk-based system to penalize and reward line management for occupational safety and health performance

Penalizing line management for the occurrence of lost time injuries has in some cases had unintended negative consequences. These are discussed. An alternative system is suggested that penalizes line management for accidents where the combination of the probability of recurrence and the maximum reasonable consequences such a recurrence may have exceeds an agreed limit. A reward is given for prompt effective control of the risk to below the agreed risk limit. The reward is smaller than the penalty. High-risk accidents require independent investigation by a safety officer using analytical techniques. Two case examples are given to illustrate the system. Continuous safety improvement is driven by a planned reduction in the agreed risk limit over time and reward for proactive risk assessment and control.