ResearchPad - beef https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Development of plasma and whole blood taurine reference ranges and identification of dietary features associated with taurine deficiency and dilated cardiomyopathy in golden retrievers: A prospective, observational study]]> https://www.researchpad.co/article/elastic_article_14758 A surge in Food and Drug Administration (FDA) consumer complaints identified concerns that legume-rich, grain-free diets were associated with nutritionally-mediated dilated cardiomyopathy (DCM). Golden retrievers represent the most reported breed affected by this condition and previous studies documented the disease is responsive to dietary change and taurine supplementation. Although dietary findings across cases are compelling, prospective studies with control groups are lacking. The role of diet in developing taurine deficiency and echocardiographic changes consistent with DCM in healthy dogs is unknown.ObjectivesWe hypothesized that golden retrievers eating non-traditional diets are at a higher risk of having taurine deficiency and nutritionally-mediated DCM compared with those eating traditional commercial diets. We aimed to compare taurine concentrations and echocardiographic indices of systolic function between golden retrievers in each diet group and elucidate associations between diet and these variables. Additionally, we aimed to generate breed-specific reference intervals for whole blood and plasma taurine concentrations.Animals86 golden retrievers.MethodsGolden retrievers eating traditional or non-traditional diets were evaluated and diet history, taurine concentrations and echocardiographic data were collected. Dietary features, taurine concentrations and echocardiographic findings were compared between diet groups. Relative risks were calculated for the likelihood of echocardiographic abnormalities and taurine deficiency in each diet group. Breed-specific reference intervals were constructed for taurine concentrations in dogs from the traditional diet group.ResultsGolden retrievers eating non-traditional diets had significantly lower taurine concentrations and more frequent systolic dysfunction. Breed specific reference intervals are higher than previously reported across breeds.ConclusionsNon-traditional diets, which were typically grain-free and contained legumes in this study, were significantly associated with and have increased relative risk for the identification of taurine deficiency and echocardiographic abnormalities consistent with nutritionally-mediated DCM. These findings were identifiable in the absence of clinical signs and support the findings of multiple previous studies and the ongoing FDA investigation. ]]> <![CDATA[Variance components for bovine tuberculosis infection and multi-breed genome-wide association analysis using imputed whole genome sequence data]]> https://www.researchpad.co/article/5c6f1539d5eed0c48467af0c

Bovine tuberculosis (bTB) is an infectious disease of cattle generally caused by Mycobacterium bovis, a bacterium that can elicit disease humans. Since the 1950s, the objective of the national bTB eradication program in Republic of Ireland was the biological extinction of bTB; that purpose has yet to be achieved. Objectives of the present study were to develop the statistical methodology and variance components to undertake routine genetic evaluations for resistance to bTB; also of interest was the detection of regions of the bovine genome putatively associated with bTB infection in dairy and beef breeds. The novelty of the present study, in terms of research on bTB infection, was the use of beef breeds in the genome-wide association and the utilization of imputed whole genome sequence data. Phenotypic bTB data on 781,270 animals together with imputed whole genome sequence data on 7,346 of these animals’ sires were available. Linear mixed models were used to quantify variance components for bTB and EBVs were validated. Within-breed and multi-breed genome-wide associations were undertaken using a single-SNP regression approach. The estimated genetic standard deviation (0.09), heritability (0.12), and repeatability (0.30) substantiate that genetic selection help to eradicate bTB. The multi-breed genome-wide association analysis identified 38 SNPs and 64 QTL regions associated with bTB infection; two QTL regions (both on BTA23) identified in the multi-breed analysis overlapped with the within-breed analyses of Charolais, Limousin, and Holstein-Friesian. Results from the association analysis, coupled with previous studies, suggest bTB is controlled by an infinitely large number of loci, each having a small effect. The methodology and results from the present study will be used to develop national genetic evaluations for bTB in the Republic of Ireland. In addition, results can also be used to help uncover the biological architecture underlying resistance to bTB infection in cattle.

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<![CDATA[Comparison of two bovine serum pregnancy tests in detection of artificial insemination pregnancies and pregnancy loss in beef cattle]]> https://www.researchpad.co/article/5c5217cbd5eed0c4847945d9

Blood tests for early detection of pregnancy in cattle based on pregnancy-associated glycoproteins (PAGs) are commercially available. The objective of these studies were to compare the accuracy of blood tests to transrectal ultrasonography in detecting AI pregnancies, and to compare the accuracy of blood tests in predicting pregnancy loss. Beef cattle from 6 herds were synchronized using a recommended CIDR based protocol (Study 1: n = 460; Study 2: n = 472). Pregnancy status was determined by transrectal ultrasonography between days 28–40 following AI, blood samples were collected at this time. In study 2 a final pregnancy determination was performed at the end of the breeding season to determine pregnancy loss. Each serum sample was examined for PAG concentrations using a microtiter plate reader and/or scored by two technicians blind to pregnancy status and pregnancy loss. For study 1 Cohen’s kappa statistics were calculated to assess the agreement between each test and transrectal ultrasonography. For study 2 data was analyzed using the GLIMMIX procedure of SAS with herd as a random effect, and loss, age, and their interaction included in the model. Agreement was good to very good for each test. There was no difference (P = 0.79) in sensitivity, but a difference (P<0.01) in specificity of the assays (88%, 64%, 87%, 90%) and in the overall percent correct (93%, 84%, 93%, 93%). There was an effect of pregnancy loss (P = 0.04), age (P = 0.0002), and their interaction (P = 0.06) on PAG concentrations. In conclusion both pregnancy tests were accurate at detecting AI pregnancies, and were in very good agreement with transrectal ultrasonography. Both tests detected differences in PAGs among females that maintained and lost pregnancy; however, prediction proved to be difficult as most females were above the threshold and would have been considered pregnant on the day of testing.

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<![CDATA[Inappropriate usage of selected antimicrobials: Comparative residue proportions in rural and urban beef in Uganda]]> https://www.researchpad.co/article/5c40f7dcd5eed0c484386b13

Introduction

In most developing countries like Uganda, antimicrobials including β-lactams and tetracyclines are used indiscriminately in livestock. When livestock get sick and treatment is necessary, some producers and veterinarians use these drugs with minimal controls to prevent residues from occurring in the beef sent to markets. This study was done to determine the presence of drug residues above acceptable limits of two commonly used antimicrobials in Uganda’s rural and urban beef.

Methods

A cross-sectional study was conducted of 134 cattle carcasses from eight different slaughter slabs over twelve weeks. This study entailed 81 samples of rural and 53 samples of urban origin. To enable detailed analysis these samples were categorized according to age (maturity), breed, and sex. For each of the 134 carcasses, three samples of liver, kidney and muscle were taken and homogeneously mixed into one sample, which was tested for β-lactam and tetracycline drug residues.

Results

The results were statistically significant for β-lactam levels (χ2 = 22.10, df = 10, p = 0.0146) with average concentration (μg/kg) of 2.93:29.3 (rural: urban), though not for tetracycline levels (χ2 = 3.594, df = 10, P = 0.9638) with average concentration (μg/kg) of 5.028:12.83 (rural: urban). Age (maturity) had significant effect at all values of antibiotic level (F(1, 68) = 5.06, p = 0.0278). Age effect was extremely significant (F(1, 68) = 15.51, p = 0.0002).

Conclusion

A significant difference existed in drug residue proportions of β-lactam and tetracycline antimicrobials among Uganda’s rural and urban beef. A significant difference also occured in drug residue proportions of these two commonly used antimicrobials related to age (maturity), but neither breed, nor sex, of Uganda’s rural and urban beef.

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<![CDATA[How do Brazilian citizens perceive animal welfare conditions in poultry, beef, and dairy supply chains?]]> https://www.researchpad.co/article/5c23f272d5eed0c484046b5a

The aim of this study was to understand the perceptions of Brazilian citizens about the general conditions of animal welfare in the poultry, beef, and dairy supply chains. To reach this aim, an online survey was conducted. The analysis was based on descriptive statistics and three logistic regression models. Results of descriptive statistics showed that citizens in Brazil had mostly negative perceptions about the conditions of animal welfare in the poultry, beef, and dairy supply chains. Results of the logistic regression models showed that citizens with a background in agricultural/veterinary sciences, and citizens who reported a higher level of knowledge about poultry and dairy supply chains were more likely to perceive the general conditions of animal welfare in these two supply chains as being bad. Citizens who reported previous contact with poultry farms were also more likely to perceive the general conditions of animal welfare in the poultry supply chain as being bad. In addition, the perception that farmers are mainly focused on the economic aspect of farming and less on animal welfare, the perception that animals do not have a good quality of life while housed on farms, and the perception that animals are not adequately transported and slaughtered, negatively impact on perceptions about the general conditions of animal welfare in the poultry, beef, and dairy supply chains.

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<![CDATA[Antibiotic resistance is lower in Staphylococcus aureus isolated from antibiotic-free raw meat as compared to conventional raw meat]]> https://www.researchpad.co/article/5c1813c8d5eed0c484775ce7

The frequent use of antibiotics contributes to antibiotic resistance in bacteria, resulting in an increase in infections that are difficult to treat. Livestock are commonly administered antibiotics in their feed, but there is current interest in raising animals that are only administered antibiotics during active infections. Staphylococcus aureus (SA) is a common pathogen of both humans and livestock raised for human consumption. SA has achieved high levels of antibiotic resistance, but the origins and locations of resistance selection are poorly understood. We determined the prevalence of SA and MRSA in conventional and antibiotic-free (AF) meat products, and also measured rates of antibiotic resistance in these isolates. We isolated SA from raw conventional turkey, chicken, beef, and pork samples and also from AF chicken and turkey samples. We found that SA contamination was common, with an overall prevalence of 22.6% (range of 2.8–30.8%) in conventional meats and 13.0% (range of 12.5–13.2%) in AF poultry meats. MRSA was isolated from 15.7% of conventional raw meats (range of 2.8–20.4%) but not from AF-free meats. The degree of antibiotic resistance in conventional poultry products was significantly higher vs AF poultry products for a number of different antibiotics, and while multi-drug resistant strains were relatively common in conventional meats none were detected in AF meats. The use of antibiotics in livestock contributes to high levels of antibiotic resistance in SA found in meat products. Our results support the use of AF conditions for livestock in order to prevent antibiotic resistance development in SA.

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<![CDATA[Rumen and plasma metabolomics profiling by UHPLC-QTOF/MS revealed metabolic alterations associated with a high-corn diet in beef steers]]> https://www.researchpad.co/article/5c084200d5eed0c484fcb6aa

High-grain diets are strongly associated with metabolic disorders in beef steers. Metabolomics can be used to explore the relationship between diet and metabolic changes, but no study has reported rumen and plasma metabolomics profiling associated with increasing dietary corn proportions in the diet of beef steers. Therefore, 12 steers paired according to similar body weights and body condition scores were randomly allocated to one of two diets: a low-corn (28.76%) diet (LCD) with a 40:60 ratio of concentrate to roughage and a high-corn (48.76%) diet (HCD) with a 60:40 ratio of concentrate to roughage. Metabolomics profiling by ultra-high-performance liquid tandem chromatography quadrupole time of flight mass spectrometry (UHPLC-QTOF/MS) showed that steers fed the HCD had increased rumen and plasma carbohydrate metabolites and amino acids, which contributed to the growth of the beef steers. However, the rumen acidity and ruminal and plasma lipopolysaccharide (LPS) concentrations significantly increased with the increase amounts of corn in the diet. In total, 717 rumen metabolites and 386 plasma metabolites were identified. By multivariate analysis, 144 rumen and 56 plasma metabolites were further identified that were significantly different between the two groups (P < 0.05 and variable influence on projection > 1). The differential metabolites in the rumen and plasma were associated with different metabolic pathways, and phenylalanine, tyrosine and tryptophan biosynthesis and phenylalanine metabolism were common key metabolic pathways for the two biofluids. In conclusion, the high-corn diet improved the growth performance of beef steers but decreased the ruminal pH and increased the LPS and harmful metabolites in the rumen and blood, which has implications for the incidence of metabolic diseases. The identified differential metabolites in both the rumen and plasma and the related metabolic pathways may contribute to the exploration of potential biomarkers for high-corn diet-based metabolic diseases.

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<![CDATA[Molecular Relationship between Strains of M. bovis from Mexico and Those from Countries with Free Trade of Cattle with Mexico]]> https://www.researchpad.co/article/5989da31ab0ee8fa60b84668

The purpose of this study was to identify relationships between spoligotypes of M. bovis from cattle in Mexico and those reported in countries with free trade of cattle with Mexico: Australia, Canada, New Zealand and the United States of America. Mexican spoligotypes were obtained from isolates collected from cattle in different parts of the country. Spoligotypes from Canada and New Zealand were obtained from different reports in the literature. Those from the United States were obtained from the database of the National Veterinary Services Laboratory in APHIS-USDA. In order to perform the analysis in a single data set, spoligotypes were all converted to binary data and classified according to www.mbovis.org or www.pasteur-guadeloupe.fr:8081. Epidemiologic information included country and species infected. From 3,198 isolates, 174 different spoligotypes were obtained, 95 were orphans. Ninety one percent of the isolates came from the Unites States (n = 1,609) and Mexico (n = 1,323). Spoligotype SB0265 is shared between Canada and the United States in cattle and wildlife. Six spoligotypes, SB0673, SB0121, SB0145, SB0971, SB0140 and SB1165, were frequent in cattle and wildlife in the United States and cattle in Mexico, suggesting wide exchange of strains. Spoligotype SB0669 was found only in Mexico. Spoligotype SB0140 was the most common in Australia and the sixth in the United States and Mexico. In a phylogenetic analysis, spoligotype SB0140 appears as the oldest spoligotype in the data set, suggesting this as the ancestral spoligotype for all spoligotypes in the five countries. Some spoligotypes are shared by animals and humans, corroborating the zoonotic importance of M. bovis.

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<![CDATA[Genome-wide association study provides strong evidence of genes affecting the reproductive performance of Nellore beef cows]]> https://www.researchpad.co/article/5989db5cab0ee8fa60be0110

Reproductive traits are economically important for beef cattle production; however, these traits are still a bottleneck in indicine cattle since these animals typically reach puberty at older ages when compared to taurine breeds. In addition, reproductive traits are complex phenotypes, i.e., they are controlled by both the environment and many small-effect genes involved in different pathways. In this study, we conducted genome-wide association study (GWAS) and functional analyses to identify important genes and pathways associated with heifer rebreeding (HR) and with the number of calvings at 53 months of age (NC53) in Nellore cows. A total of 142,878 and 244,311 phenotypes for HR and NC53, respectively, and 2,925 animals genotyped with the Illumina Bovine HD panel (Illumina®, San Diego, CA, USA) were used in GWAS applying the weighted single-step GBLUP (WssGBLUP) method. Several genes associated with reproductive events were detected in the 20 most important 1Mb windows for both traits. Significant pathways for HR and NC53 were associated with lipid metabolism and immune processes, respectively. MHC class II genes, detected on chromosome 23 (window 25-26Mb) for NC53, were significantly associated with pregnancy success of Nellore cows. These genes have been proved previously to be associated with reproductive traits such as mate choice in other breeds and species. Our results suggest that genes associated with the reproductive traits HR and NC53 may be involved in embryo development in mammalian species. Furthermore, some genes associated with mate choice may affect pregnancy success in Nellore cattle.

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<![CDATA[Failure of Passive Immune Transfer in Calves: A Meta-Analysis on the Consequences and Assessment of the Economic Impact]]> https://www.researchpad.co/article/5989da20ab0ee8fa60b7ea3f

Low colostrum intake at birth results in the failure of passive transfer (FPT) due to the inadequate ingestion of colostral immunoglobulins (Ig). FPT is associated with an increased risk of mortality and decreased health and longevity. Despite the known management practices associated with low FPT, it remains an important issue in the field. Neither a quantitative analysis of FPT consequences nor an assessment of its total cost are available. To address this point, a meta-analysis on the adjusted associations between FPT and its outcomes was first performed. Then, the total costs of FPT in European systems were calculated using a stochastic method with adjusted values as the input parameters. The adjusted risks (and 95% confidence intervals) for mortality, bovine respiratory disease, diarrhoea and overall morbidity in the case of FPT were 2.12 (1.43–3.13), 1.75 (1.50–2.03), 1.51 (1.05–2.17) and 1.91 (1.63–2.24), respectively. The mean (and 95% prediction interval) total costs per calf with FPT were estimated to be €60 (€10–109) and €80 (€20–139) for dairy and beef, respectively. As a result of the double-step stochastic method, the proposed economic estimation constitutes the first estimate available for FPT. The results are presented in a way that facilitates their use in the field and, with limited effort, combines the cost of each contributor to increase the applicability of the economic assessment to the situations farm-advisors may face. The present economic estimates are also an important tool to evaluate the profitability of measures that aim to improve colostrum intake and FPT prevention.

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<![CDATA[Staphylococcus aureus Nasal Carriage among Beefpacking Workers in a Midwestern United States Slaughterhouse]]> https://www.researchpad.co/article/5989db22ab0ee8fa60bcf8ec

Occupational contact with livestock is an established risk factor for exposure to livestock-associated methicillin-resistant Staphylococcus aureus (MRSA), particularly among industrial swine workers. While S. aureus is known to infect cattle, livestock-associated S. aureus carriage among workers in the beef production chain has received limited attention. Beefpacking workers, who slaughter, butcher and process cattle, have intensified exposure to potentially infectious animal materials and may be at risk of livestock-associated S. aureus exposure. We conducted a cross-sectional study of beefpacking workers (n = 137) at an industrial slaughterhouse in the Midwestern United States to evaluate prevalence and characteristics of S. aureus nasal colonization, specifically the absence of the scn gene to identify putative association with livestock, antibiotic susceptibility, presence of Panton-Valentin leukocidin (PVL) genes lukS-PV and lukF-PV, and spa type. Overall prevalence of S. aureus nasal carriage was 27.0%. No workers carried livestock-associated MRSA. Methicillin-sensitive S. aureus isolates (MSSA) recovered from five workers (3.6%) lacked the scn gene and were considered putative livestock-associated S. aureus (pLA-SA). Among pLA-SA isolates, spa types t338, t748, t1476 and t2379 were identified. To our knowledge, these spa types have not previously been identified as associated with livestock. Prevalence of human-adapted MRSA carriage in workers was 3.6%. MRSA isolates were identified as spa types t002, t008 and t024, and four of five MRSA isolates were PVL-positive. To date, this is the first study to indicate that industrial beefpacking workers in the United States may be exposed to livestock-associated S. aureus, notably MSSA, and to spa types not previously identified in livestock and livestock workers. Occupational exposure to livestock-associated S. aureus in the beef production chain requires further epidemiologic investigation.

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<![CDATA[Comprehensive Evaluation and Implementation of Improvement Actions in Butcher Shops]]> https://www.researchpad.co/article/5989d9fbab0ee8fa60b720e9

Foodborne pathogens can cause acute and chronic diseases and produce a wide range of symptoms. Since the consumption of ground beef is a risk factor for infections with some bacterial pathogens, we performed a comprehensive evaluation of butcher shops, implemented improvement actions for both butcher shops and consumers, and verified the impact of those actions implemented. A comprehensive evaluation was made and risk was quantified on a 1–100 scale as high-risk (1–40), moderate-risk (41–70) or low-risk (71–100). A total of 172 raw ground beef and 672 environmental samples were collected from 86 butcher shops during the evaluation (2010–2011) and verification (2013) stages of the study. Ground beef samples were analyzed for mesophilic aerobic organisms, Escherichia coli and coagulase-positive Staphylococcus aureus enumeration. Salmonella spp., E. coli O157:H7, non-O157 Shiga toxin-producing E. coli (STEC), and Listeria monocytogenes were detected and isolated from all samples. Risk quantification resulted in 43 (50.0%) high-risk, 34 (39.5%) moderate-risk, and nine (10.5%) low-risk butcher shops. Training sessions for 498 handlers and 4,506 consumers were held. Re-evaluation by risk quantification and microbiological analyses resulted in 19 (22.1%) high-risk, 42 (48.8%) moderate-risk and 25 (29.1%) low-risk butcher shops. The count of indicator microorganisms decreased with respect to the 2010–2011 period. After the implementation of improvement actions, the presence of L. monocytogenes, E. coli O157:H7 and stx genes in ground beef decreased. Salmonella spp. was isolated from 10 (11.6%) ground beef samples, without detecting statistically significant differences between both study periods (evaluation and verification). The percentage of pathogens in environmental samples was reduced in the verification period (Salmonella spp., 1.5%; L. monocytogenes, 10.7%; E. coli O157:H7, 0.6%; non-O157 STEC, 6.8%). Risk quantification was useful to identify those relevant facts in butcher shops. The reduction of contamination in ground beef and the environment was possible after training handlers based on the problems identified in their own butcher shops. Our results confirm the feasibility of implementing a comprehensive risk management program in butcher shops, and the importance of information campaigns targeting consumers. Further collaborative efforts would be necessary to improve foodstuffs safety at retail level and at home.

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<![CDATA[A Meta-Assembly of Selection Signatures in Cattle]]> https://www.researchpad.co/article/5989dac6ab0ee8fa60bb2665

Since domestication, significant genetic improvement has been achieved for many traits of commercial importance in cattle, including adaptation, appearance and production. In response to such intense selection pressures, the bovine genome has undergone changes at the underlying regions of functional genetic variants, which are termed “selection signatures”. This article reviews 64 recent (2009–2015) investigations testing genomic diversity for departure from neutrality in worldwide cattle populations. In particular, we constructed a meta-assembly of 16,158 selection signatures for individual breeds and their archetype groups (European, African, Zebu and composite) from 56 genome-wide scans representing 70,743 animals of 90 pure and crossbred cattle breeds. Meta-selection-scores (MSS) were computed by combining published results at every given locus, within a sliding window span. MSS were adjusted for common samples across studies and were weighted for significance thresholds across and within studies. Published selection signatures show extensive coverage across the bovine genome, however, the meta-assembly provides a consensus profile of 263 genomic regions of which 141 were unique (113 were breed-specific) and 122 were shared across cattle archetypes. The most prominent peaks of MSS represent regions under selection across multiple populations and harboured genes of known major effects (coat color, polledness and muscle hypertrophy) and genes known to influence polygenic traits (stature, adaptation, feed efficiency, immunity, behaviour, reproduction, beef and dairy production). As the first meta-assembly of selection signatures, it offers novel insights about the hotspots of selective sweeps in the bovine genome, and this method could equally be applied to other species.

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<![CDATA[Differential Acute Postprandial Effects of Processed Meat and Isocaloric Vegan Meals on the Gastrointestinal Hormone Response in Subjects Suffering from Type 2 Diabetes and Healthy Controls: A Randomized Crossover Study]]> https://www.researchpad.co/article/5989da5fab0ee8fa60b90a2f

Background

The intake of meat, particularly processed meat, is a dietary risk factor for diabetes. Meat intake impairs insulin sensitivity and leads to increased oxidative stress. However, its effect on postprandial gastrointestinal hormone (GIH) secretion is unclear. We aimed to investigate the acute effects of two standardized isocaloric meals: a processed hamburger meat meal rich in protein and saturated fat (M-meal) and a vegan meal rich in carbohydrates (V-meal). We hypothesized that the meat meal would lead to abnormal postprandial increases in plasma lipids and oxidative stress markers and impaired GIH responses.

Methods

In a randomized crossover study, 50 patients suffering from type 2 diabetes (T2D) and 50 healthy subjects underwent two 3-h meal tolerance tests. For statistical analyses, repeated-measures ANOVA was performed.

Results

The M-meal resulted in a higher postprandial increase in lipids in both groups (p<0.001) and persistent postprandial hyperinsulinemia in patients with diabetes (p<0.001). The plasma glucose levels were significantly higher after the V-meal only at the peak level. The plasma concentrations of glucose-dependent insulinotropic peptide (GIP), peptide tyrosine-tyrosine (PYY) and pancreatic polypeptide (PP) were higher (p<0.05, p<0.001, p<0.001, respectively) and the ghrelin concentration was lower (p<0.001) after the M-meal in healthy subjects. In contrast, the concentrations of GIP, PYY and PP were significantly lower after the M-meal in T2D patients (p<0.001). Compared with the V-meal, the M-meal was associated with a larger increase in lipoperoxidation in T2D patients (p<0.05).

Conclusion/Interpretation

Our results suggest that the diet composition and the energy content, rather than the carbohydrate count, should be important considerations for dietary management and demonstrate that processed meat consumption is accompanied by impaired GIH responses and increased oxidative stress marker levels in diabetic patients.

Trial Registration

ClinicalTrials.gov NCT01572402

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<![CDATA[Effect of Topically Applied Anaesthetic Formulation on the Sensitivity of Scoop Dehorning Wounds in Calves]]> https://www.researchpad.co/article/5989daafab0ee8fa60baacd2

The post-operative effects of three formulations of topical anaesthetic and a cornual nerve block on the sensitivity of scoop dehorning wounds in calves were compared in two trials. In Trial 1, 21 female Holstein dairy calves aged 8 to 24 weeks were randomly allocated to two groups: (1) scoop dehorning with a post-operative application of a novel topical anaesthetic powder (DTAP, n = 10); and (2) scoop dehorning with a post-operative application of a novel topical anaesthetic ethanol liquid (DTAE, n = 11). In Trial 2, 18 castrated male and 18 female Hereford beef calves aged 16 to 20 weeks were randomly allocated to four groups: (1) scoop dehorning with a pre-operative cornual nerve block of lignocaine (DCB, n = 9); (2) scoop dehorning with a post-operative application of the novel topical anaesthetic ethanol liquid from Trial 1 (DTAE, n = 9); (3) scoop dehorning with a post-operative application of a topical anaesthetic gel (DTAG, n = 9); and (4) sham dehorning (CON, n = 9). Sensitivity was assessed by scoring the behavioural response of calves to stimulation of the wound or skin at time points before and after treatment. In Trial 1, DTAP calves had a greater probability of displaying more severe responses than DTAE calves at 90 and 180 min (P < 0.001). In Trial 2, at 1 h, DTAG calves had a greater probability of displaying more severe responses than CON calves. At 2 h onwards, all dehorned calves had a greater probability of displaying more severe responses than CON calves (P < 0.001). There were no differences between the responses of DCB, DTAG and DTAE calves at any time point. Topical anaesthetic formulations result in almost immediate but temporary anaesthesia of the wound following scoop dehorning in calves and may provide a practical option for pain relief on-farm.

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<![CDATA[Effect of Antimicrobial Consumption and Production Type on Antibacterial Resistance in the Bovine Respiratory and Digestive Tract]]> https://www.researchpad.co/article/5989db21ab0ee8fa60bcf662

The aim of this study was to investigate the relationship between antimicrobial use and the occurrence of antimicrobial resistance in the digestive and respiratory tract in three different production systems of food producing animals. A longitudinal study was set up in 25 Belgian bovine herds (10 dairy, 10 beef, and 5 veal herds) for a 2 year monitoring of antimicrobial susceptibilities in E. coli and Pasteurellaceae retrieved from the rectum and the nasal cavity, respectively. During the first year of observation, the antimicrobial use was prospectively recorded on 15 of these farms (5 of each production type) and transformed into the treatment incidences according to the (animal) defined daily dose (TIADD) and (actually) used daily dose (TIUDD). Antimicrobial resistance rates of 4,174 E. coli (all herds) and 474 Pasteurellaceae (beef and veal herds only) isolates for 12 antimicrobial agents demonstrated large differences between intensively reared veal calves (abundant and inconstant) and more extensively reared dairy and beef cattle (sparse and relatively stable). Using linear mixed effect models, a strong relation was found between antimicrobial treatment incidences and resistance profiles of 1,639 E. coli strains (p<0.0001) and 309 Pasteurellaceae (p≤0.012). These results indicate that a high antimicrobial selection pressure, here found to be represented by low dosages of oral prophylactic and therapeutic group medication, converts not only the commensal microbiota from the digestive tract but also the opportunistic pathogenic bacteria in the respiratory tract into reservoirs of multi-resistance.

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<![CDATA[Disparities in Beef Tapeworm Identification Rates in the Abattoirs of Gauteng Province, South Africa: A Descriptive Epidemiologic Study]]> https://www.researchpad.co/article/5989d9daab0ee8fa60b67417

Background

Bovine Taenia saginata cysticercus infections (also called bovine cysticercosis or beef measles) is usually diagnosed in cattle only during post-mortem meat inspection. The aim of this study was to investigate the identification rates of these infections in and to identify predictors/determinants of variations in the identification rates in abattoirs in Gauteng province, South Africa.

Methods

Retrospective data for over 1.4 million cattle carcasses inspected in 26 abattoirs between January 2010 and December 2013 were used for the study. The identification rates (proportion of bovine Taenia saginata cysticercus positive carcasses) were computed and generalized estimating equations used to identify predictors/determinants of identification rates.

Results

The overall identification rate was 0.70% (95% CI: 0.45, 0.95). Significantly (p< 0.05) lower rates were reported during summer (0.55%) than other seasons. Some geographic areas reported significantly (p<0.05) higher rates than others. The identification rates in high throughput abattoirs was significantly (p<0.05) higher (RR: 9.4; 95% CI: 4.7–19.1) than in low throughput abattoirs. Similarly, the identification rates among animals from feedlots were significantly (p<0.05) higher (RR: 1.6; 95% CI: 1.7–3.5) than those from non-feedlot sources. No significant (p>0.05) association was identified between identification rates and either the number of meat inspectors per abattoir or the provider of inspection services.

Conclusion

Although no significant association was found between identification rates and provider of inspection services, follow-up studies will need to be done to specifically investigate the potential conflict of interest arising from the fact that abattoir owners hire meat inspection services directly. Capture of abattoir surveillance data needs to include farm address and for each case to be reported separately. Finally, information on the type of identified cysts (alive or calcified) need to be collected to help better estimate risk to consumers. This study provides useful baseline data to guide future studies, surveillance and control efforts.

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<![CDATA[Optimal Design of Low-Density SNP Arrays for Genomic Prediction: Algorithm and Applications]]> https://www.researchpad.co/article/5989daecab0ee8fa60bbf846

Low-density (LD) single nucleotide polymorphism (SNP) arrays provide a cost-effective solution for genomic prediction and selection, but algorithms and computational tools are needed for the optimal design of LD SNP chips. A multiple-objective, local optimization (MOLO) algorithm was developed for design of optimal LD SNP chips that can be imputed accurately to medium-density (MD) or high-density (HD) SNP genotypes for genomic prediction. The objective function facilitates maximization of non-gap map length and system information for the SNP chip, and the latter is computed either as locus-averaged (LASE) or haplotype-averaged Shannon entropy (HASE) and adjusted for uniformity of the SNP distribution. HASE performed better than LASE with ≤1,000 SNPs, but required considerably more computing time. Nevertheless, the differences diminished when >5,000 SNPs were selected. Optimization was accomplished conditionally on the presence of SNPs that were obligated to each chromosome. The frame location of SNPs on a chip can be either uniform (evenly spaced) or non-uniform. For the latter design, a tunable empirical Beta distribution was used to guide location distribution of frame SNPs such that both ends of each chromosome were enriched with SNPs. The SNP distribution on each chromosome was finalized through the objective function that was locally and empirically maximized. This MOLO algorithm was capable of selecting a set of approximately evenly-spaced and highly-informative SNPs, which in turn led to increased imputation accuracy compared with selection solely of evenly-spaced SNPs. Imputation accuracy increased with LD chip size, and imputation error rate was extremely low for chips with ≥3,000 SNPs. Assuming that genotyping or imputation error occurs at random, imputation error rate can be viewed as the upper limit for genomic prediction error. Our results show that about 25% of imputation error rate was propagated to genomic prediction in an Angus population. The utility of this MOLO algorithm was also demonstrated in a real application, in which a 6K SNP panel was optimized conditional on 5,260 obligatory SNP selected based on SNP-trait association in U.S. Holstein animals. With this MOLO algorithm, both imputation error rate and genomic prediction error rate were minimal.

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<![CDATA[How to Build a Standardized Country-Specific Environmental Food Database for Nutritional Epidemiology Studies]]> https://www.researchpad.co/article/5989daadab0ee8fa60baa1ae

There is a lack of standardized country-specific environmental data to combine with nutritional and dietary data for assessing the environmental impact of individual diets in epidemiology surveys, which are consequently reliant on environmental food datasets based on values retrieved from a heterogeneous literature. The aim of this study was to compare and assess the relative strengths and limits of a database of food greenhouse gas emissions (GHGE) values estimated with a hybrid method combining input/output and LCA approaches, with a dataset of GHGE values retrieved from the literature. France is the geographical perimeter considered in this study, but the methodology could be applied to other countries. The GHGE of 402 foodstuffs, representative of French diet, were estimated using the hybrid method. In parallel, the GHGE of individual foods were collected from existing literature. Median per-food-category GHGE values from the hybrid method and the reviewed literature were found to correlate strongly (Spearman correlation was 0.83), showing similar rankings of food categories. Median values were significantly different for only 5 (out of 29) food categories, including the ruminant meats category for which the hybrid method gave lower estimates than those from existing literature. Analysis also revealed that literature values came from heterogeneous studies that were not always sourced and that were conducted under different LCA modeling hypotheses. In contrast, the hybrid method helps build reliably-sourced, representative national standards for product-based datasets. We anticipate this hybrid method to be a starting point for better environmental impact assessments of diets.

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<![CDATA[Development of a Sandwich ELISA for EHEC O157:H7 Intimin γ1]]> https://www.researchpad.co/article/5989da54ab0ee8fa60b8e9a6

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a zoonotic pathogen of worldwide importance that causes foodborne infections in humans. Intimin gamma 1 (intimin γ1) is one of the most important outer membrane proteins required for EHEC’s intimate adhesion to epithelial cells. Here, we generated a polyclonal antibody (pAb) and a monoclonal antibody (mAb) against intimin γ1 to develop a double antibody sandwich ELISA (DAS-ELISA) with increased sensitivity and specificity for measuring EHEC O157:H7. To achieve this goal, a rabbit pAb was used as a capture antibody, and a mouse mAb was a detection antibody. No cross-reactivity was observed with the other genera of pathogenic bacteria tested with the DAS-ELISA, which included Salmonella enteritidis, Shigella flexneri type 2, Listeria monocytogenes, Streptococcus suis type 2, and other 18 serotype E. coli. Detection limits of the DAS-ELISA were 1 × 103 CFU/mL for EHEC O157:H7 cultures, 1 × 104 CFU/g before enrichment, and 1 × 102 CFU/g after enrichment of contaminated samples. Field samples (n = 498) were tested using a previously established duplex-PCR method and compared to our DAS-ELISA. The DAS-ELISA had a specificity of 94.4%, a sensitivity of 91.5% and accuracy of 94.0% compared with duplex-PCR. The DAS-ELISA developed here can be applied to EHEC O157:H7 quantification in food, animal, and environmental samples.

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