Browsing by Subject "Poultry"

Now showing 1 - 10 of 10
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    4-H Skills For Life Animal Science Series. Scratching the Surface: Project Activity Guide
    (Minnesota Extension Service, 1994) Busch, Shannon; Hamre, Mel; Zurcher, Thomas D.; Struwe, John; Adams, Al; Varghese, Sam; Siemens, Cindy; Adams, Jim
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    61st Minnesota Nutrition Conference
    (University of Minnesota, Extension Service, 2000-09) University of Minnesota Extension Service
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    Colony Brooder Houses, Revised November 1935.
    (University of Minnesota, Agricultural Extension Service, 1935-11) Smith, A.C.; University of Minnesota, Agricultural Extension Division; White, H.B.
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    Comparative genomics of Ornithobacterium rhinotracheale and determination of strain-specific pathogenicity and virulence
    (2021-09) Smith, Emily
    The subsequent chapters of this dissertation will address many of the current knowledge gaps surrounding ORT. First, comparative genomics of clinical ORT isolates from several US commercial turkey producers will highlight the genetic similarities and differences between currently circulating ORT strains. Second, a study comparing these clinical isolates to commensal isolates of ORT will reveal whether there are genetic differences between clinical and commensal isolates. Finally, a series of challenge studies will determine if clinical ORT strains that differ genomically result in differences clinically, and if controlled exposure is effective in preventing negative outcomes associated with ORT.
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    Ecology and Epidemiology of Campylobacter Jejuni In Broiler Chickens
    (2019-06) Hwang, Hae Jin
    Campylobacteriosis, predominantly caused by Campylobacter jejuni, is a common, yet serious foodborne illness. With consumption and handling of poultry products as the most important risk factor of campylobacteriosis, reducing Campylobacter contamination in poultry products is considered the best public health intervention to reduce the burden and costs associated with campylobacteriosis. To this end, there is a need to improve our understanding of epidemiology and ecology of Campylobacter jejuni in poultry. The overall goal of this dissertation is to answer knowledge gaps regarding Campylobacter ecology and epidemiology in broiler chickens with an emphasis on the pre-harvest components of the broiler production system. The objectives included: (1) to assess current interventions and control measures practiced by the U.S. broiler industry to reduce Campylobacter contamination on broiler chicken products; (2) to investigate indirect selective pressures responsible for the persistence of fluoroquinolone-resistant Campylobacter jejuni in broiler chickens; and (3) to describe the temporal changes in broiler litter bacterial microbiota with respect to bird age, flock cycle, antibiotic use and presence of Campylobacter on farms. For the first objective, we surveyed key stakeholders of the U.S. broiler industry, including poultry veterinarians, farm managers and processing plant managers. The survey respondents reported the use of various pre- and post-harvest interventions that are recommended by the USDA-FSIS to decrease Campylobacter contamination in broiler chickens and on carcasses. Yet, the survey results also revealed the lack of understanding of Campylobacter epidemiology among the respondents, indicating that further education and training programs are necessary to improve understanding of Campylobacter among the key stakeholders which can lead to a reduction of Campylobacter contamination and improvement in food safety. To investigate indirect selective pressures allowing persistence of Campylobacter jejuni in broiler chickens, we tested two hypotheses: limited bioavailability in poultry and activity of microcin B17. However, we found that the hypotheses tested were unlikely to be responsible for the persistence of fluoroquinolone-resistant Campylobacter jejuni despite the lack of fluoroquinolone use in the industry. Lastly, we investigated the temporal changes in the broiler litter microbiota by sampling seven commercial broiler farms over two flock cycles. We found that flock cycle and age of bird were two significant farm variables driving the bacterial diversity and composition of the litter microbiota. Additionally, when the litter bacterial microbiota was compared between Campylobacter-positive and Campylobacter-negative samples, a lower abundance of Lactobacillus was observed among the positive samples. Overall, the work presented in this dissertation demonstrates collective efforts to improve our understanding of Campylobacter jejuni in broiler chickens using multidisciplinary approaches.
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    Investigating the Potential of Lemongrass Essential Oil Against Multidrug-Resistant Salmonella Heidelberg in Broiler Chickens
    (2018-10) Dewi, Grace
    Foodborne illness continues to persist as a global public health concern, despite technological advances. In particular, Salmonella has remained a major foodborne illness-causing pathogen in the United States. Epidemiological studies indicate that poultry are among the major source of Salmonella in developed nations, as food-producing animals like chickens often serve as natural hosts for the pathogen. Among the many serovars of Salmonella enterica, Salmonella enterica serovar Heidelberg has emerged as a pathogen of concern as it causes infections of greater severity in humans and possesses high potential for multidrug resistance. As Salmonella colonization in broiler chickens increases the risk of contamination during subsequent stages of processing, antimicrobial intervention strategies are warranted to ensure food safety and prevent outbreaks from occurring. Decades of efforts to control Salmonella in food systems have indicated that the problem must be approached holistically, with the best intervention strategy ideally applied at multiple stages of production. In that regard, the current study aimed to investigate the efficacy of lemongrass essential oil (LGEO), a generally recognized as safe (GRAS) compound that is obtained from plants of the Cymbopogon species, in reducing MDR S. Heidelberg in vitro, in broiler chicken, and on broiler chicken carcass. The direct effects of LGEO against MDR S. Heidelberg virulence factors, which are important for colonization, survival, and transmission, were first assessed through a series of in vitro assays. Additionally, the potential quorum sensing modulating properties of LGEO against S Heidelberg was indirectly assessed using the biosensor organism, Chromobacterium violaceum. C. violaceum produces violacein, a violet pigment under the vio operon regulation, which is easily observable and quantifiable. Effect of LGEO against S. Heidelberg multiplication was examined through macrodilution assays performed in either tryptic soy broth (TSB) or poultry cecal contents. The effect of LGEO on S. Heidelberg motility was assessed using a motility assay where S. Heidelberg was spot inoculated on the center of semi-solid agar plates supplemented with LGEO. Assays that investigated the effect of LGEO against S. Heidelberg biofilms formation and inactivation of mature biofilms were performed using 96-well microtiter plate assays and 24-well tissue culture plate assays, respectively. Finally, the quorum sensing modulation of LGEO was assessed based on violacein synthesis by C. violaceum. At concentrations of 0.5% (vol/vol) or higher, LGEO was effective in inhibiting multiplication S. Heidelberg by at least 4.0 log10 CFU/mL after 24 hours in TSB and poultry cecal contents (P ≤ 0.05). Addition of 0.15% LGEO in semi-solid motility agar yielded complete inhibition of S. Heidelberg motility (P ≤ 0.05). Concentrations of 0.15% and 1% LGEO were also found effective against MDR S. Heidelberg biofilm formation and inactivation of mature MDR S. Heidelberg biofilms (P ≤ 0.05). Additionally, a reduction in violacein production by C. violaceum was observed with 0.5% and 1% LGEO (P ≤ 0.05). Results of the in vitro assays indicate the potential of LGEO to mitigate the persistence and dissemination of MDR S. Heidelberg in poultry production systems. Subsequently, in vivo experiments were performed to determine the efficacy of LGEO as an antimicrobial supplement either through feed or drinking water to reduce S. Heidelberg colonization in broilers. The efficacy of in-feed supplementation of LGEO against MDR S. Heidelberg was evaluated in 3-week-old broiler chickens. Efficacy of LGEO supplementation through drinking water was first examined in 5-week-old broiler chickens and then in 7-week-old broiler chickens. All birds, except those in NC groups, in all studies, were challenged by crop gavage with 105, 104, and 108 CFU/mL MDR S. Heidelberg, at 2-, 4-, and 6-weeks of age, respectively. For both feed studies where 1% LGEO was supplemented through feed, no significant reduction in S. Heidelberg populations was observed (P > 0.05). Likewise, when supplemented through drinking water, 0.5% LGEO resulted in no significant reduction in both 5- and 7-week old broiler chickens (P > 0.05). However, a significant reduction of 2.4 log10 CFU/gram cecal S. Heidelberg was observed in one replicate involving 5-week old broilers (P < 0.05). In conclusion, the results of this study indicated that LGEO supplementation in either feed or water was not effective in reducing MDR S. Heidelberg colonization in broiler chickens at the current concentrations tested. Finally, the last set of experiments examined the effect of LGEO dip treatments on MDR S. Heidelberg attachment to broiler chicken skin and meat samples. Skin from drumsticks and breast meat samples were spot-inoculated with 4.0 log10 CFU MDR S. Heidelberg per sample and dipped in water containing 0.5, 1, or 2% LGEO for 2, 3, or 5 minutes at either 54°C or 4°C, individually, as well as at 54°C and 4°C in sequence. At 2%, LGEO consistently resulted in significant reduction of MDR S. Heidelberg on both skin and meat samples, though the magnitude of reduction was lesser on meat than on skin (P < 0.05). Sequential dip treatments performed on skin yielded comparable results to that observed in individual dip treatments at scalding temperatures. However, subsequent dip treatments were also not as effective on meat compared to skin samples. All concentrations of LGEO effectively inactivated S. Heidelberg from the scalding and chilling treatment waters for both skin and meat samples (P < 0.05). The results indicate that LGEO could be utilized as a natural antimicrobial intervention in scalding and chilling waters to reduce S. Heidelberg on poultry carcasses. In conclusion, the results are indicative of the direct antibacterial effects which LGEO exerts on S. Heidelberg in vitro and on broiler chicken skin samples. However, results of the in vivo study suggest that additional studies must examine the possible factors that may have impeded LGEO’s efficacy against foodborne pathogens in broiler chickens. Overall, the efficacy of LGEO observed on retail broiler chicken samples is indicative of its potential use to control MDR S. Heidelberg transmission in poultry production systems.
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    Light turkey syndrome: field study and inoculation trial.
    (2012-07) Calvert, Alamanda Joy
    Light Turkey Syndrome (LTS) is characterized by lower than expected body weights of tom turkey flocks at market. Turkey producers have taken notice of LTS over the last five years. During brooding from two to three weeks of age is when weight gains begin to fall below what had previously been achieved. Speculation suggests that lighter poults are experiencing a different set of factors than the heavier weight poults in commercial flocks. The hypothesis for the field study was that poults from two weight groups (heavy and light) would have different histopathology scores for the intestine and immune tissue, different pathogens present and different xylose absorption. The objective of the inoculation trial was to determine if inoculated poults raised in research settings would exhibit similar attributes as the poults from the field study. In addition to the factors that had been looked at for the field study; weight gain, feed intake and feed conversion data were also determined. In both studies gut contents was collected for analysis by multiplex RT-PCR for astrovirus, rotavirus, reovirus and by culture methods for Salmonella, Campylobacter, E. coli and total plate counts for aerobic, anaerobic, lactobacilli and heterofermentative lactobacilli. Intestinal tissue was collected for scoring of heterophilic and lymphocytic infiltrates and select immune tissue was also scored. Xylose absorption was measured in plasma samples at zero and 60 minutes post gavage. Samples were collected at one, two and three weeks of age in the field study from four MN commercial flocks, two ND commercial flocks and two MN research flocks. Samples were collected at 14 days of age (seven days post inoculation) in the inoculation trial. For both studies more differences were seen between the different flocks than between the heavy and light weight groups. Salmonella and astrovirus were found in all flocks in the field study but reovirus was only found in two of the MN commercial flocks. In the field study histological differences were seen between weight groups with two flocks having an increased acute immune response in the light weight and heavy poults in all flocks showing increased lymphocytes in the intestinal tissue. For immune tissue lymphocytic necrosis and atrophy of the bursa were present in more light weight poults than heavy weight poults. Xylose absorption was increased in heavy weight poults in three of the commercial flocks when compared to light weight poults. In the inoculation trial control poults had the best weight gain and feed conversion with poults gavaged with the inoculums from commercial flocks having the worst. Heterophilic infiltrates were the highest in the control poults and lymphocytic infiltrates were highest in the light weight poults. Lymphocytic necrosis was found in more of the light weight poults. No differences were seen in xylose absorption between the heavy, light and control groups in the inoculation trial. Light turkey syndrome cannot be easily defined by a specific pathogen’s presence though a few different pathogens may likely play a role in the reduced weight gain seen in LTS poults. Histologically the gut and immune tissue indicate active immune responses that are decreasing the amount of nutrients available for growth of the bird. Nutrient absorption only appears to be negatively affected if the poult is actively showing signs of disease.
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    Our Changing Poultry Enterprise and its Relation to Dairy Cattle and Hogs
    (Minnesota Agricultural Experiment Station, 1951-10) Hady, Frank T.; Nodland, Truman
    MANY CHANGES have taken place in the poultry enterprise during recent years. Some of them have been rather spectacular. Better breeding, better feeding and care, and better disease control have resulted in a large increase in the number of eggs laid per hen and in an increase in the average size of farm flocks. Whenever possible, farmers should make full use of these improvements in poultry production to increase their farm incomes. It is equally desirable, however, that they do not allow their enthusiasm for poultry to cause them to overlook the opportunities available to them in other forms of livestock. As only about five per cent of the farmers get as much as half of their income from poultry, it is evident that poultry is customarily found in combination with other farm enterprises. Usually, the livestock combination includes poultry, cattle, and hogs.
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    Risk-Based Evaluation Of The Public Health Impact Of Food Safety Interventions For The Control Of Salmonella Spp. In The Chicken Meat Production Chain
    (2017-05) Gonzalez, Rolando
    The aim of this work was to develop a risk-based decision analysis framework of farm to table food safety interventions for the control of Salmonella spp. in the chicken meat production chain, using chicken breasts and ground chicken as the model food systems. This framework should assist chicken producers, processors and policy makers when evaluating and selecting the most cost-effective and feasible pre-harvest and post-harvest interventions to control Salmonella spp. The approach included defining the risk factors for Salmonella spp. contamination in the chicken meat production chain, identifying existing and proposed pre- and post-harvest interventions for controlling Salmonella spp., prioritizing pre- and post-harvest interventions based on the reduction of the overall public health risk, developing a quantitative risk assessment to predict the number of Salmonella cases in the US population per year and the impact of individual and combined intervention strategies in reducing the Salmonella public health burden, and finally, applying cost-benefit analysis to identify the most cost-effective measures. The results suggest that the use of peroxyacetic acid as a single intervention applied at post-chill is the most cost-effective intervention to both control Salmonella spp. and meet regulatory performance standards in chicken meat production. It also became evident that there is a need to update the body of published literature to better understand the impact of all stages of the chicken meat production chain, from pre- and post-harvest through consumer handling and cooking, particularly on levels of Salmonella spp.
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    Source, Winter 2016
    (University of Minnesota Extension, 2016) University of Minnesota Extension