Broiler Operations Research Articles

Emergence of Salmonella Infantis carrying the pESI megaplasmid in commercial farms of five major integrated broiler operations in Korea

Considering Salmonella transmission occurs through several routes in integrated broiler operations, control of nontyphoidal Salmonella in commercial farms is essential. This study aimed to compare the distribution of persistent Salmonella serovars in environments and dead chickens between 5 major integrated broiler operations in Korea. The prevalence of Salmonella-positive farms in dust prior to placement by operations was 0 to 25%, but the prevalence in dust and feces at the time of depletion was increased to 16.7 to 41.7% and 16.7 to 66.7%, respectively. Moreover, the prevalence of farms with Salmonella in chickens that died within 1 week old and at 4 to 5 weeks old ranged from 8.3 to 58.3% and 16.7 to 41.7%, respectively. The prevalence of Salmonella enterica serovar Infantis-positive farms in dust prior to placement and in chickens that died within 1 week old was 5.2 and 3.4%, respectively, but the prevalence in dust and feces at the time of depletion and in chickens that died at 4 to 5 weeks old was significantly increased to 27.6, 41.4, and 20.7%, respectively (P < 0.05). Interestingly, the plasmid of emerging S. Infantis (pESI) was only identified in S. Infantis, and the prevalence of multidrug-resistance was significantly higher in pESI-positive S. Infantis (99.2%) than in pESI-negative S. Infantis (6.7%) (P < 0.05). The distribution of pulsotypes between pESI-positive and pESI-negative S. Infantis were varied, but a majority of S. Infantis were clustered only 2 pulsotypes. Moreover, pESI-positive S. Infantis harbored more virulence factors than pESI-negative S. Infantis. This study is the first report on characteristics of S. Infantis carrying the pESI plasmid in commercial broiler farms in Korea.

Challenges in the profitability of small-scale broiler farming by avoiding injudicious use of drugs and additives

The aim of the current study was to determine the present scenario of injudicious use of drugs and additives in small-scale broiler operations and whether broilers can be produced successfully and profitably without the injudicious use of drugs and additives. First, a survey was undertaken in relation to farmers' basic information and general management methods in commercial broilers, with special attention given to the usage of medications and additives in drinking water. Second, based on the survey data, an experimental trial was carried out to compare the growth performance and economic profitability of rearing broilers with and without the use of said drugs and additives. A total of 540 broiler DOCs were allotted into three treatments: T1 = self-formulated feed (SFF) with judicious use of drugs and additives; T2 = commercial feed with judicious use of drugs and additives (JUDA) and T3 = commercial feed with injudicious use of drugs and additives (InJUDA), with six replications (30 birds/replication) in each. The results showed that the farmers used a variety of drugs and additives in 35 days of broiler rearing; however, the farmers usually did not consult with veterinary practitioners, instead relying on and being instructed by local dealers and medicine company representatives. Although the medications and additives account for almost 6–8% of total production costs, the experimental trial clearly demonstrated that the broilers kept with either JUDA or InJUDA showed statistically (p < 0.05) similar BW (2181.93 g & 2222.53 g/bird), BWG (2110.0 g & 2129.91 g/bird), and FCR (1.62 & 1.57, respectively), whereas broilers in the SFF group showed significantly lower growth performances (BW = 1799.31 g/bird, BWG = 1746.19 g/bird, and FCR = 1.93, respectively). The net profit per kg bird in the JUDA group was substantially (p < 0.05) greater (BDT- 27.34/-), followed by the SFF group (BDT- 25.56/) and the InJUDA group (BDT- 24.49/-). Taken together, these findings suggest that profitable broiler farming is possible without the injudicious use of drugs and additives.

Solar-assisted poultry production in small-scale farms: a case study in the Bekaa semi-arid region, Lebanon

BackgroundIn Lebanon, poultry production is one of the major components of the agricultural sector; however, it suffers from increasing energy costs necessary to cover poultry heating requirements. This affects the profits of brooding farms, namely, small-scale farms in rural areas. Few studies have addressed the use of renewable energy in the poultry industry in Lebanon, with most having focused on modelling ventilation and air quality requirements in poultry houses. Therefore, there is a need to investigate the efficiency of renewable energy sources in providing heating requirements for poultry production. Accordingly, this study evaluates the performance of a solar-assisted, localized heating system in providing heat requirements for chicks in a renovated green poultry house in the Bekaa semi-arid rural region in Lebanon. For this aim, two brooding cycles were conducted during the warm and cold seasons in a greenhouse and were later replicated in a conventional poultry house.ResultsThe energy inputs in the green and conventional houses, respectively, were 33,995.39 and 40,656.97 MJ (1000 birds)−1 in the warm season, and 37,058.25 and 45,770.05 MJ (1000 birds)−1 in the cold season. Calculated energy efficiency values for the green and conventional poultry houses were, respectively, 0.58 and 0.50 in the warm season, and 0.46 and 0.41 in the cold season. The net return was negative for both systems and the benefit-to-cost ratio from broiler production was calculated to be 0.49 and 0.50 in the green and conventional houses, respectively. Life cycle cost analysis showed that adopting the green heating system in the studied farm would entail an 18.89% increase in cost over a period of 20 years as compared to the conventional system.ConclusionIt was concluded that poultry production is not profitable in small-scale farms in the studied area in Lebanon. The use of renewable energy might be more suited for large-scale broiler operations to achieve their purpose in reducing overall production costs. Optimization of the green system to fully satisfy the poultry energy requirements would render it more economically competitive.

A Study of Cross-Protection between Eimeria maxima Immunovariants.

For reasons unknown, Eimeria maxima is unique among Eimeria species infecting chickens in the immunovariability it displays among isolates from different geographical areas. Eimeria maxima oocysts (named EmaxAPU3) were isolated late in grow-out (6 weeks) from litter in a commercial broiler operation that was using Eimeria vaccination as the coccidiosis control program. Cross-protection studies (n = 4) were conducted in immunologically naïve chickens between EmaxAPU3 and two E. maxima lab strains (EmaxAPU1, EmaxAPU2) by immunizing with one E. maxima strain and challenging with either the homologous or heterologous E. maxima. As measured by oocyst output, immunization with EmaxAPU1 protected against homologous challenge (EmaxAPU1) and against heterologous challenge with EmaxAPU3, but not against EmaxAPU2. Similarly, immunization with EmaxAPU3 protected against homologous challenge (EmaxAPU3) and against heterologous challenge with EmaxAPU1, but not against EmaxAPU2. Immunization of chickens with EmaxAPU2 elicited a protective response against homologous challenge (EmaxAPU2), but not against EmaxAPU1 nor EmaxAPU3. The most plausible explanation for the appearance of this immunovariant late in grow-out is that E. maxima APU3 escaped immunity directed to E. maxima antigenic types in the commercial vaccine.

Techno-economic feasibility of using solar energy in small-scale broiler production

Poultry farming is an energy intensive industry necessitating a substantial amount of fossil fuel consumption and leading to elevated operational expenses. This study investigated the economic feasibility of implementing renewable energy in small-scale broiler farms to decrease their dependency on fossil fuels and increase their profit. Assessment was based on experimental data collected from broiler production operations carried out in a green poultry house equipped with solar renewable energy systems and a conventional poultry house operated on conventional energy source. The experiments were conducted during both the warm and cold seasons in a semi-arid rural area in Lebanon. Average annual costs and benefits from broiler operations were calculated based on a total of 8 production cycles/year. Cost-benefit analysis was conducted to assess the viability of introducing renewable energy in broiler production. In addition, a twenty-year financial feasibility analysis was performed for both green and conventional systems using two different time value of money parameters; the Net Present Value (NPV) and the Benefit Cost Ratio (BCR). The results showed that broiler production using conventional energy achieved a total cost of 2.25 % lower than the cost incurred using green energy and higher total revenues of 5.55 %. Negative NPV and less than 1 BCR values were computed for both green and conventional systems demonstrating that broiler production in the study area is non-profitable in small-scale broiler farms, independently of the source of energy. Accordingly, it is recommended to adopt renewable energy cooperatives based on partnership between small-scale farms. This cooperative-based partnership model has proven to allow the adoption of renewable energy sources as sustainable and economically viable approach, contributing to increased farmers' revenues. Government subsidies and financial incentives are also essential to ensure the success and sustainability of the renewable energy cooperatives.

Current status of β-lactam antibiotic use and characterization of β-lactam-resistant Escherichia coli from commercial farms by integrated broiler chicken operations in Korea

β-Lactam antibiotics are one of the most clinical importance in human and veterinary medicine because they are used for both preventive and therapeutic purposes against several gram-positive, gram-negative, and anaerobic organisms. In this study, it was confirmed that β-lactams (81.1%) were found to be significantly prescribed the most among 74 farms in 5 integrated broiler operations, and single prescription (84.6%), 2-day (41.5%) or 3-day (40.0%) administration, and 15 to 22 d of age (67.7%) administration was significantly higher in the farms (P < 0.05). Among the E. coli isolated from 74 farms in 5 integrated broiler operations, β-lactam-resistant E. coli isolates were detected more frequently in fecal sample (94.6%) than in dust sample (60.8%) (P < 0.05). The prevalence of MDR in β-lactam-resistant isolates, ranging from 88.1 to 96.5%, was significantly higher than that in non-β-lactam-resistant isolates (P < 0.05), without significant differences among operations. Of 466 β-lactam-resistant isolates, 432 (92.7%) isolates harbored β-lactamase genes. The non-extended-spectrum β-lactamase (ESBL) gene blaTEM-1 (81.8%) showed the highest prevalence among isolates, followed by the non-ESBL gene blaTEM-135 (6.4%) (P < 0.05). Five ESBL genes, SHV-12, OXA-1, CTX-M-27, CTX-M-55, and CTX-M-65, were found in 0.9 to 6.0% of the isolates. The pAmpC gene blaCMY-2 was detected in 17 isolates (3.6%). These results suggest that feces and dust are important reservoirs of antimicrobial-resistant bacteria, highlighting the need to strengthen farm management regulations, such as cleaning, disinfection, and litter disposal and to reduce the use of antibiotics in broiler operations.

Comprehensive analysis of biosecurity practices and antimicrobial use in broiler chicken production by integrated operations in Korea

Integrated broiler operations that allow producers to combine various biosecurity and sanitation practices account for approximately 97.6% of chicken meat production in Korea, but it is not well known about the biosecurity level or compliance with regulations for each operation. Therefore, the objective this study was to analyze the current adoption of biosecurity practices and trends in antimicrobial use in 74 farms from 5 major integrated broiler chicken operations (A-E). The highest stock densities of more than 65 birds per 3.3 m2 (0.5 birds/ft2) showed in 66.7 and 33.3% of the farms in operations A and C, respectively. Also, the livability rate of 98% or less was observed in 73.3 and 93.4% of the farms, in operation A and C, respectively, which lower than other operations. Moreover, it was observed that 60.0 and 40.0% of farms in operations B and C reused litter 3 or more times. Among the 74 farms, the most common antimicrobials prescription frequency was 2 times (39.2%), and the prescription to β-lactams antibiotics (45.3%) showed the significantly highest (P < 0.05). The highest administration of antimicrobials was at 15 to 22-days old (42.7%), and most of them were recommended by veterinarian (80.7%). Footbath disinfectant and spraying outside the poultry house were performed in most of the farms (64.9 and 83.8%, respectively), but the use of quicklime (36.5%) and drinking water disinfectant (18.9%) was low in farms. Most of the farms washed vehicles for transportation of poultry (87.8%) and feed (100%) before arriving at the farms, however, 40.5% of the farms used little or no disinfectants when washing the transport vehicles. Moreover, wild birds, and cats and dogs were well controlled on most of the farms (each 94.6%), but only 74.3% of farms offered rodent control programs. Also, only 27.0% of the farms used farm-specific shoes and clothing as well as footbath disinfection for entrance. These findings can be useful in developing policies and guidelines for sustainable and responsible broiler chicken production and reduction of antimicrobial use in Korea.

Evaluating draft Environmental Protection Agency emissions models for broiler operations

Evaluating draft Environmental Protection Agency emissions models for broiler operations

Situational analysis on fluoroquinolones use and characterization of high-level ciprofloxacin-resistant Enterococcus faecalis by integrated broiler operations in South Korea.

Fluoroquinolones are classified as "critically important antimicrobials for human medicine"; however, their extensive use in livestock poses a significant health risk to humans as it leads to the rapid spread of antimicrobial resistance. This study confirmed that 40.0%-71.4% of the farms in three of the five integrated broiler operations were administered ciprofloxacin (CIP). Moreover, preventive purposes (60.9%), veterinarian prescriptions (82.6%), drinking water route (100%), and 1 to 3 days (82.6%) of age were significantly highest (P < 0.05). 194 high-level ciprofloxacin-resistant (HLCR) Enterococcus faecalis (E. faecalis) were found in 65 of 74 farms, and of which, the prevalence of qnrA (63.9%), tetM (60.3%), ermB (64.9%), blaz (38.7%), and catA (34.0%) was significantly highest (P < 0.05). 154 (79.4%) isolates showed MDR, and the distribution of MDR was significantly differences among the operations (P < 0.05). All HLCR E. faecalis possessed double mutations in gyrA and parC, and S83I/S80I (90.7%) mutations were most commonly identified. Interestingly, the distribution of isolates with MICs ≥ 512 for both CIP and moxifloxacin was significantly higher in CIP-administered farms (56.5%) than in non-CIP-administered farms (41.4%) (P < 0.05). Also, the prevalence of strong or moderate biofilm formers in HLCR E. faecalis was significantly higher than that of weak and no biofilm formers (P < 0.05). HLCR E. faecalis were heavily distributed in the broiler farms in Korea; therefore, it is necessary to minimize the prevalence of resistant bacteria via structural management regulations such as cleaning and disinfection of farm environments.

Genetic characterization of third- or fourth-generation cephalosporin-resistant avian pathogenic Escherichia coli isolated from broilers.

The third- or fourth-generation cephalosporins (3GC or 4 GC) are classified as "critically important antimicrobials for human medicine" by WHO, but resistance to these drugs is increasing rapidly in avian pathogenic E. coli (APEC). This study investigated the distribution and genetic characteristics of 3GC- or 4 GC-resistant APEC isolates from five major integrated broiler operations in Korea. The prevalence of 3GC- or 4GC-resistant APEC isolates in 1-week-old broilers was the highest in farms of operation C (53.3%); however, the highest prevalence of these isolates in 4-week-old broilers was the highest on the farms of operation A (60.0%), followed by operations E (50.0%) and C (35.7%). All 49 3GC- or 4GC-resistant APEC isolates had at least one β-lactamase-encoding gene. The most common β-lactamase-encoding genes was extended-spectrum β-lactamase gene, bla CTX-M-15, detected in 24 isolates (49.0%), followed by bla TEM-1 (32.7%). Sixteen isolates (32.7%) harbored class 1 integrons, and four isolates (8.2%) showed different gene cassette-arrangements. However, only 1 of 26 isolates harboring class 2 integrons carried a gene cassette. Furthermore, both CRISPR 1 and 2 arrays were detected in most isolates (36 isolates; 73.5%), followed by CRISPR 2 (18.4%) and CRISPR 1 (4.1%). Interestingly, CRISPR 2 was significantly more prevalent in multidrug resistant (MDR)-APEC isolates than in non-MDR APEC isolates, whereas CRISPR 3 and 4 were significantly more prevalent in non-MDR APEC isolates (each 11.1%; p < 0.05). None of the protospacers of CRISPR arrays were directly associated with antimicrobial resistance. Our findings indicate that the distribution and characteristics of 3GC or 4GC-resistant APEC isolates differed among the integrated broiler operations; moreover, improved management protocols are needed to control the horizontal transmission of 3GC or 4GC-resistant APEC isolates.

Zoonoses Transfer, Factory Farms and Unsustainable Human–Animal Relations

Infectious diseases are rooted in unsustainable and unjust human–animal relationships. Zoonoses are facilitated by human proximity to animals, epidemiological risk embedded within factory farms, and exploitation of animals and humans in these intensive livestock production systems. The five major categories of epidemiological risk that factory farms propel include: intensification of production for which homogenous populations are congregated, creation of multi-species farms for which different animals are held within the same farm, long and intensive animal transport increases the likelihood of interaction with other wildlife, ecological characteristics of the pathogen lead to altered pathogen dynamics and antibiotic resistance within a human population through the overuse of antibiotics. Layer and broiler operations in the North American context illustrate these linkages. One Health is offered as a concluding conceptual and aspirational frame for pursuing a more sustainable and just world. This article offers two main messages. First, our relationships with animals directly impact the health of human populations through the transmission and creation of Emerging Infectious Diseases (EIDs). Second, adopting One Health offers a means forward for more just and sustainable human–animal relations and reduction of zoonoses transmission.

Impact of the gastrointestinal microbiome and fermentation metabolites on broiler performance

Optimal broiler performance is dependent on several factors such as bird genetics, environment management, and nutrition. The gastrointestinal tract microbial ecology and metabolic activities have long been considered factors contributing to broiler performance responses. However, until recently, it was difficult to define the impact of the gastrointestinal microorganisms on the broiler host. With advances in microbiome sequencing technology, there has been a rapid increase in data generated using both experimental and commercial broiler operations. As the gastrointestinal microbiome data becomes more in-depth, opportunities to link microbiota composition to broiler performance metrics such as broiler growth rate and feed conversion efficiency have emerged. In parallel, with the increased understanding of the microbiota, there has been a shift to modulate the microbiome in order to alter metabolic patterns such as fermentation products. In this review, fermentation pathways and metabolites and the relationship with the microbiome will be discussed. Additionally, this review will connect these patterns and interpretations with current broiler performance data and the potential future directions these relationships could take the broiler industry.

Exposure Assessment at a Pullet Barn - A Case Study

ABSTRACT Poultry production is an integral part of agriculture and of the U.S. economy, accounting for millions of eggs and chicken products consumed annually. Most ubiquitous to the poultry industry from farm production to research are broiler and layer poultry operations, with pullet operations at the forefront. Although essential to the cycles of production, there is a dearth of evidence regarding the occupational exposure risks of pullet production. The aim of this case study was to measure total dust and ammonia levels during the growth cycle of pullets. Ammonia and total dust concentrations were measured as single day measurements at three different points of time during the 16.5-week growth cycle of pullet flocks using two fixed sampling stations configured to represent the breathing zone height of poultry workers. As birds grew from chicks to hens, concentrations of total dust and ammonia increased. Notably, from 3 weeks-of-age to 9 weeks-of-age concentrations of total dust increased from 1.1–1.2 mg/m3 to 16.0–18.0 mg/m3; and from 9 weeks-of-age to 15 weeks-of-age, dust concentrations reached 43.0–50.0 mg/m3. Concentrations of ammonia also increased from 9 weeks to 15 weeks from 1.1–2.7 ppm to 22.0–30.0 ppm. Both levels of ammonia and total dust reached levels that have the potential to induce adverse health effects among farmers raising pullets.

Prevalence and antimicrobial resistance phenotypes of Salmonella species recovered at various stages of broiler operations in Hathazari, Bangladesh

Background and Aim: Dissemination of multidrug-resistant (MDR) Salmonella through food chains has serious health implications, with higher rates of morbidity and mortality. Broiler meat remains a major reservoir of Salmonella contamination. The lack of proper hygiene in local broiler operations has, therefore, prompted this research into the assessment of Salmonella contamination in local shops and associated antimicrobial resistance (AMR) phenotypes. Materials and Methods: A total of 55 broiler samples including skin, meat, and swab samples from chopping and dressing sites were included in the study. The samples were collected from broiler shops in Hathazari, Bangladesh, and screened for the presence of Salmonella strains using culture-based methods. The isolates were biochemically characterized and further tested for AMR to eight common antibiotics using the disk diffusion technique. Results: Salmonella contaminations were identified in 29% (16/55) of the broiler samples. Swab samples collected from the chopping sites appeared to be contaminated in higher proportions (33%) than those collected from the dressing areas (25%). On the other hand, the skin samples (50%) were detected with a higher percentage of contamination than the meat samples (25%). All Salmonella isolates showed resistance toward at least one of the eight antibiotics used. Although none of the isolates was resistant to all antibiotics, 18.75% showed resistance to a maximum of seven antibiotics. Resistance to nalidixic acid was most prevalent (87.5%), followed by sulfamethoxazole-trimethoprim (81.25%), erythromycin (81.25%), tetracycline (75%), streptomycin (56.25%), ampicillin-clavulanic acid (50%), chloramphenicol (43.75%), and cefotaxime (18.75%). The resistance patterns of the isolates were found to be highly diverse. The most frequently observed pattern was the following: Ampicillin-clavulanic acid-sulfamethoxazole-trimethoprim-nalidixic acid-tetracycline-chloramphenicol-streptomycin-erythromycin. Conclusion: The relatively high prevalence of MDR strains in the samples underlies an urgent need for surveillance and control measures concerning hygiene and antibiotic use in local broiler operations.

Assessment of Novel Water Applied Prebiotic to Evaluate Gut Barrier Failure and Performance in Two Commercial Trials in Brazil. A Pilot Study With an Economic Perspective.

The present study evaluated the effect of administration of a water applied prebiotic on gut barrier failure (Experiment 1) and performance in broiler chickens under commercial conditions (Experiment 2). Experiment 1, one thousand four hundred and forty day-of-hatch Ross broiler chickens were assigned to one of two experimental groups (n = 30 replicate pens/treatment; n = 24 chicks/pen). Birds in the treated group received the prebiotic orally in the drinking water (0.2ml/bird) on days 3 and 17 of age. The second group served as the untreated control group. On d 18, intestinal samples were analyzed by qRT-PCR to determine the expression of MUC2, IL-8, TGF-β4, and ZO-1. On d 17, d 28, and d 35 blood samples were collected to determine circulating endotoxin levels. On d 28, mucosal intestinal scrapping was collected to measure relative total sIgA levels. At d 42, liver samples were collected to evaluate liver bacterial translocation. In Experiment 2, the prebiotic was evaluated in two commercial trials. Chickens were raised under normal production conditions and fed a 3-phase commercial basal diet with enramycin (7 g/ton). In Trial 1, 8,974,237 broiler chickens were treated with the prebiotic. The prebiotic was administered in the drinking water (0.2 mL/bird) following the manufacture label instructions at day three and seventeen of life. Production parameters were compared to historical information from the company over the same broiler operation and production cycles. For trial 2, 921,411 broiler chickens were treated with the prebiotic as in Trial 1. In Experiment 1, treated chickens showed a significant (P < 0.05) increase in mRNA expression of MUC2, TGF-β4, IL-8, ZO-1, and sIgA, but a significant reduction of serum endotoxin levels and incidence of liver lactose positive bacterial translocation when compared to non-treated chickens. In both trials of Experiment 2, a significant reduction in total mortality was observed in the treated chickens when compared with the historical farm data. Economic analysis utilizing the total percent of mortality revealed a $1: $2.50 USD and $1: $4.17 USD return for Trial 1 and Trial 2, respectively. The results suggest that the prebiotic positively influences gastrointestinal integrity and performance.

Ammonia emissions and dispersion from broiler production.

Ammonia (NH3 ) has been used as a target gas for nuisance complaints to restrict or close poultry operations near encroaching rural development. There are conflicting data on NH3 emissions from broiler production across the United States. The purpose of this research is to compare emission rates from a Georgia broiler operation across seasons and with other geographical areas in the United States. Comparison of seasonal and geographical emission rates showed large seasonal variation in NH3 emissions for eastern U.S. sites but little seasonal variation in the semi-arid region of the United States. Differences in production management practices, ambient temperature, and animal density did not appear to explain differences in emissions between regions; however, the climatic influence of ambient humidity and litter management practices are thought to be key factors in the generation of emissions.

Prevalence of non-typhoidal Salmonella and risk factors on poultry farms in Chitwan, Nepal.

Background and Aim:Poultry is becoming an increasingly important source of protein in the Nepalese diet. The Chitwan region of Nepal is the hub of the emerging poultry industry. Little is known about the prevalence of non-typhoidal Salmonella (NTS) on poultry farms or the role of farm management practices that may contribute to the presence of NTS on farms. The role of poultry in the transmission of Salmonella enterica to humans is also poorly defined. This descriptive study seeks establish baseline data through estimation of the prevalence of NTS on broiler and layer operations in various farms of the Chitwan district of Nepal.Materials and Methods:Based on district documents on poultry production and meat marketing, a purposive sampling of 18 commercial poultry farms comprising ten broilers farms and eight layers farms was conducted. Environmental samples including water, litter, feces, feed, farm, and eggshell swabs were randomly collected from each farm. Samples were cultured and tested for the presence of NTS; positives were serotyped, and antimicrobial susceptibility determined. A comprehensive farm and practice questionnaire was administered to each farm manager.Results:The farm level point prevalence rate was 55% (10 of 18 farms) for S. enterica. Of the total 288 farm environmental samples collected, 26 samples (9%) were positive. The rate of isolation varied according to the origin of samples: Water (27.5%), feces (10.6%), litter (8.6%), farm swabs (5%), feed (1.8%), and eggshells (0%). Farm management variables/risk factors are summarized and categorized as non-modifiable and modifiable for analysis. Broiler operations were more likely to be positive than layer operations as were poultry houses with two or less open sides. All-in/all-out management style was found to be protective. Due to the small sample size (18 farms), no associations reached statistical significance.Conclusion:Based on environmental sampling results, NTS is highly prevalent on the poultry farms in the Chitwan district of Nepal. Certain risk factors are associated with finding NTS on farms. Our findings are generally in agreement with other studies in similar countries with rapidly emerging poultry industries. The identification of risk factors provides owners, technicians, and veterinarians with some guidance to help reduce the prevalence of NTS on farms. This baseline data are critical to understanding the epidemiology of zoonotic strain of NTS in the region and are necessary for the design of future studies and mitigation plans and underlines the need for a one-health approach to protect public health-related to Salmonella spp. from poultry farms.

Chondronecrosis with osteomyelitis in broilers: further defining a bacterial challenge model using standard litter flooring and protection with probiotics

This report demonstrates that high levels of lameness can be induced by a limited bacterial challenge in drinking water for birds raised on litter flooring, comparable with lameness induced by the gold standard for inducing lameness, growth on suspended wire flooring. The bacterium used in the challenge was cultured from lesions in birds induced for bacterial chondronecrosis with osteomyelitis (BCO) in the wire-flooring model so the epidemiology appears similar. The litter-flooring model could better approximate broiler operations. Furthermore, the work demonstrates that 2 commercial probiotics (GalliProTect and GalliProMax) can reduce lameness in the bacterial challenge litter-flooring model. Lameness attributable to BCO is one of the most significant animal welfare issues for broiler production. The wire-flooring and litter-flooring models afford alternatives for understanding the etiology, and epidemiology of BCO, and development of management strategies to reduce lameness. Probiotics afford a promising management strategy. The results suggest that the probiotic protection may extend beyond just intestinal health and intestinal barrier function.

Characteristics of linezolid-resistant Enterococcus faecalis isolates from broiler breeder farms

Linezolid is an oxazolidinone class antibiotic used for treatment infections caused by various multidrug-resistant gram-positive pathogens including enterococci. However, recently, linezolid-resistant isolates in animals are considered as a human health hazard. In a broiler operation system, antimicrobial resistance can be transferred to the environment and commercial broiler via the fecal–oral route. Therefore, this study was conducted to investigate the prevalence and characteristics of linezolid-resistant Enterococcus faecalis (E. faecalis) from broiler parent stock in a broiler operation system. Among 297 E. faecalis isolates from 85 flocks in 8 broiler breeder farms, the prevalence of chloramphenicol- and linezolid-resistant isolates was 0 to 12.1% and 0 to 8.0%, respectively; however, there were no significant differences between farms. Therefore, a total of 14 (4.7%) chloramphenicol- and/or linezolid-resistant E. faecalis showed resistance to 7 or more antimicrobial classes. The drug-resistance gene optrA, which can confer resistance to linezolid, tedizolid, and phenicols, was found in 8 (2.69%) isolates, and 7 (2.36%) of the 8 optrA-positive isolates co-carried the phenicol exporter gene fexA. However, E. faecalis isolates from 3 of 8 broiler breeder farms only carried the optrA and/or fexA genes. As linezolid is one of the last antimicrobial treatments of choice for multidrug-resistant gram-positive pathogens including E. faecalis, the presence of antibiotic-resistant E. faecalis in broiler breeder farms should be monitored to prevent the introduction of linezolid-resistant strains to the food chain.

Economic Impacts from an On-Farm Highly Pathogenic Avian Influenza Event in Tennessee

In March of 2017, two outbreaks of avian influenza, one highly- and one low-pathogenic, were reported in Tennessee poultry breeding flocks. This study estimates the potential economic impacts of a larger hypothetical event, in particular, indicating the magnitude of effects for poultry producers, industry organizations, policymakers, and other industry stakeholders. The economic impacts are estimated both with and without reductions in forward-linked processing of broiler breeders and broiler operations with depopulation rates of 10 to 25 percent in a nine-county area in the south-central part of Tennessee. Estimated reductions in gross regional product ranged from $6.7 million to $16.8 million.