Genomic evaluation of feed efficiency in US Holstein heifers.

There is growing interest in improving feed efficiency traits in dairy cattle. The objectives of this study were to estimate the genetic parameters of residual feed intake (RFI) and its component traits [dry matter intake (DMI), metabolic body weight (MBW), and average daily gain (ADG)] in Holstein heifers, and to develop a system for genomic evaluation for RFI in Holstein dairy calves. The RFI data were collected from 6,563 growing Holstein heifers (initial body weight = 261 ± 52 kg; initial age = 266 ± 42 d) for 70 d, across 182 trials conducted between 2014 and 2022 at the STgenetics Ohio Heifer Center (South Charleston, OH) as part of the EcoFeed program, which aims to improve feed efficiency by genetic selection. The RFI was estimated as the difference between a heifer's actual feed intake and expected feed intake, which was determined by regression of DMI against midpoint MBW, age, and ADG across each trial. A total of 61,283 SNPs were used in genomic analyses. Animals with phenotypes and genotypes were used as training population, and 4 groups of prediction population, each with 2,000 animals, were selected from a pool of Holstein animals with genotypes, based on their relationship with the training population. All traits were analyzed using univariate animal model in DMU version 6 software. Pedigree information and genomic information were used to specify genetic relationships to estimate the variance components and genomic estimated breeding values (GEBV), respectively. Breeding values of the prediction population were estimated by using the 2-step approach: deriving the prediction equation of GEBV from the training population for estimation of GEBV of prediction population with only genotypes. Reliability of breeding values was obtained by approximation based on partitioning a function of the accuracy of training population GEBV and magnitudes of genomic relationships between individuals in the training and prediction population. Heifers had DMI (mean ± SD) of 8.11 ± 1.59 kg over the trial period, with growth rate of 1.08 ± 0.25 kg/d. The heritability estimates (mean ± SE) of RFI, MBW, DMI, and growth rate were 0.24 ± 0.02, 0.23 ± 0.02, 0.27 ± 0.02, and 0.19 ± 0.02, respectively. The range of genomic predicted transmitted abilities (gPTA) of the training population (-0.94 to 0.75) was higher compared with the range of gPTA (-0.82 to 0.73) of different groups of prediction population. Average reliability of breeding values from the training population was 58%, and that of prediction population was 39%. The genomic prediction of RFI provides new tools to select for feed efficiency of heifers. Future research should be directed to find the relationship between RFI of heifers and cows, to select individuals based on their lifetime production efficiencies.

Coadministration of the Campylobacter jejuni N-Glycan-Based Vaccine with Probiotics Improves Vaccine Performance in Broiler Chickens.

Source attribution studies report that the consumption of contaminated poultry is the primary source for acquiring human campylobacteriosis. Oral administration of an engineered Escherichia coli strain expressing the Campylobacter jejuni N-glycan reduces bacterial colonization in specific-pathogen-free leghorn chickens, but only a fraction of birds respond to vaccination. Optimization of the vaccine for commercial broiler chickens has great potential to prevent the entry of the pathogen into the food chain. Here, we tested the same vaccination approach in broiler chickens and observed similar efficacies in pathogen load reduction, stimulation of the host IgY response, the lack of C. jejuni resistance development, uniformity in microbial gut composition, and the bimodal response to treatment. Gut microbiota analysis of leghorn and broiler vaccine responders identified one member of Clostridiales cluster XIVa, Anaerosporobacter mobilis, that was significantly more abundant in responder birds. In broiler chickens, coadministration of the live vaccine with A. mobilis or Lactobacillus reuteri, a commonly used probiotic, resulted in increased vaccine efficacy, antibody responses, and weight gain. To investigate whether the responder-nonresponder effect was due to the selection of a C. jejuni "supercolonizer mutant" with altered phase-variable genes, we analyzed all poly(G)-containing loci of the input strain compared to nonresponder colony isolates and found no evidence of phase state selection. However, untargeted nuclear magnetic resonance (NMR)-based metabolomics identified a potential biomarker negatively correlated with C. jejuni colonization levels that is possibly linked to increased microbial diversity in this subgroup. The comprehensive methods used to examine the bimodality of the vaccine response provide several opportunities to improve the C. jejuni vaccine and the efficacy of any vaccination strategy.IMPORTANCECampylobacter jejuni is a common cause of human diarrheal disease worldwide and is listed by the World Health Organization as a high-priority pathogen. C. jejuni infection typically occurs through the ingestion of contaminated chicken meat, so many efforts are targeted at reducing C. jejuni levels at the source. We previously developed a vaccine that reduces C. jejuni levels in egg-laying chickens. In this study, we improved vaccine performance in meat birds by supplementing the vaccine with probiotics. In addition, we demonstrated that C. jejuni colonization levels in chickens are negatively correlated with the abundance of clostridia, another group of common gut microbes. We describe new methods for vaccine optimization that will assist in improving the C. jejuni vaccine and other vaccines under development.

Candidate genes for carcass traits in a tropical-adapted Brazilian composite beef breed.

Backfat thickness (BFT) and ribeye area (REA) are important production traits but, because they are measured late in the animal's life, they have not been efficiently included in breeding programs. The aim of this study was to evaluate whether single nucleotide polymorphisms (SNPs) mapped to the leptin, PPARGC1A, PSMC1, CRH, and FABP4 genes, which influence BFT and REA in Canchim cattle, a composite beef breed (5/8 Charolais + 3/8 Zebu). BFT and REA phenotypic records were obtained by ultrasound measurements from 18-month-old animals. All SNP markers were genotyped by restriction fragment length polymorphism-polymerase chain reaction. Restricted maximum likelihood analysis revealed that the non-synonymous SNP located in exon 2 of the FABP4 gene has an additive effect on BFT (P ≤ 0.05). Significant allele substitution effects showed that the substitution of G by A may lead to a decrease of 0.1055 mm in mean BFT. This information can be used for inclusion of this trait-associated marker in commercial SNP panels.

Whole-genome analysis for backfat thickness in a tropically adapted, composite cattle breed from Brazil.

Backfat thickness affects the preservation of the beef carcass after slaughter and confers organoleptic characteristics assessed by the consumer. One of the breeding goals for Canchim, a tropically adapted breed, is to comprehensively increase fat thickness. Our goals were to identify genomic regions associated with backfat in Canchim populations and validate the association of single nucleotide polymorphisms (SNPs) overlapping previously identified QTL regions known to affect fat deposition. Fifteen animals with lower and 15 animals with higher residues for backfat, according to a linear model using the SAS GLM procedure, were selected from a population of 1171 animals and genotyped using the BovineSNP50 BeadChip. Initial analysis revealed more than 100 SNPs that discriminated the tails of phenotypic distribution. One extended region of association included the centromeric region of chromosome (Chr) 14. Because this region overlapped with QTL from previous reports, we developed SNP assays to interrogate two linkage disequilibrium blocks, one in the centromeric region and another in the middle region of Chr 14 to confirm the association. The analysis validated the presence of specific haplotypes affecting fat thickness.

Candidate gene region for control of rib eye area in Canchim beef cattle.

Investigation of molecular marker effects on production traits is essential to define marker assisted selection strategies in beef cattle. We looked for a possible association of molecular markers and backfat thickness (BFT) and rib eye area (REA) in Canchim (5/8 Charolais + 3/8 Zebu) and MA (offspring of Charolais bulls and 1/2 Canchim + 1/2 Zebu cows) animals raised exclusively on pasture. Traits were measured on 987 individuals from seven herds from two Brazilian States (São Paulo and Goiás), in March and April from 2005 to 2007, when animals were, on average, 19 months of age. Five microsatellite markers lying in QTL regions for BFT and REA (BMS490 and ETH10 on chromosome 5, INRA133 and ILSTS090 on chromosome 6, and BMS2142 on chromosome 19) were genotyped and association analyses were performed under an animal model using the restricted maximum likelihood method. After correction for multiple tests, a significant effect of microsatellite BMS490 on REA was observed, suggesting that at least one QTL affecting carcass traits in this region of the BTA5. No significant effect on BFT was observed for these markers.

Body mass index and carpal tunnel syndrome.

Carpal tunnel syndrome (CTS) has been correlated to body mass index (BMI) increase. The present study was done in a Brazilian population to compare BMI values in the following groups: first, CTS vs. controls subjects, and, second CTS groups of increasing median sensory latency (MSL). According to MSL>/=3.7 ms (wrist-index finger, 14 cm), median/ulnar sensory latency difference>/=0.5 ms (ring finger, 14 cm) or median palm-to-wrist (8 cm) latency>/=2.3 ms (all peak-measured), 141 cases (238 hands) had CTS confirmation. All were symptomatic; previous surgery and polyneuropathy were excluded; mean age 50.3; 90.8% female. Controls subjects (n=243; mean age 43.0; 96. 7% female) and CTS cases had BMI calculated (kg/m2). Controls subjects had a mean BMI of 25.43+/-4.80 versus 28.38+/-4.69 of all CTS cases, a statistically significant difference (p < 0.001). The CTS groups of increasing MSL severity do not show additional increase in BMI (28.44 for incipient, 28.27 for mild, 28.75 for moderate and 29.0 for severe). We conclude that CTS cases have a significant correlation with higher BMI when compared to controls subjects; however, higher BMI do not represent a statistically significant increasing risk for more severe MSL.

Wrist and palm indexes in carpal tunnel syndrome.

According to median sensory latency >/= 3.7 ms (wrist-index finger [WIF], 14 cm), median/ulnar sensory latency difference to ring finger >/= 0.5 ms (14 cm) or median midpalm (8 cm) latency >/= 2.3 ms (all peak-measured), 141 Brazilian symptomatic patients (238 hands) have CTS confirmation. Wrist ratio (depth divided by width, WR) and a new wrist/palm ratio (wrist depth divided by the distance between distal wrist crease to the third digit metacarpophalangeal crease, WPR) were measured in all cases. Previous surgery/peripheral neuropathy were excluded; mean age 50.3 years; 90.8% female. Control subjects (486 hands) have mean age 43.0 years; 96.7% female. The mean WR in controls was 0.694 against 0.699, 0.703, 0.707 and 0.721 in CTS groups of progressive WIF severity. The mean WPR in controls was 0.374 against 0.376, 0.382, 0.387 and 0.403 in CTS groups of WIF progressive severity. Both were statistically significant for the last two groups (WIF > 4.4 ms, moderate, and, WIF unrecordable, severe). BMI increases togetherwith CTS severity and WR. It was concluded that both WR/WPR have a progressive correlation with the severity of CTS but with statistically significance only in groups moderate and severe. In these groups both WR and BMI have progressive increase and we believe that the latter could be a risk factor as important as important WR/WPR.

[Intestinal schistosomiasis and its control in North-East Brazil]. / La schistosomose intestinale et son contrôle dans le Nord-Est du Brésil.

Intestinal schistosomiasis is endemic in the sugar cane belt near the coast of North-East Brazil. The environment and poor living conditions of the agricultural workers of this area combine to perpetuate the transmission of this disease. However, a new epidemiological pattern is emerging on the coast of Pernambuco State, where workers from the endemic area are building weekend homes without proper drainage. National control programs have led to a dramatic reduction in severe infections. However, they have not yet succeeded in stopping disease transmission altogether. The transfer of responsibility for control to local public health structures, which is currently underway, should improve the situation.

Phylogenetic analysis, biofilm production, and antimicrobial resistance profile of Escherichia coli isolated from slaughtered pigs / Análise filogenética, produção de biofilme e perfil de resistência antimicrobiana de Escherichia coli isoladas de suínos abatidos

Enteric diseases of bacterial origin are frequent in the pig industry, of particular notoriety are the colibacillosis that mainly affect piglets and cause great damage to the swine industry worldwide. The aim of the study was to analyze phylogenetics, to detect biofilm production, and to determine antimicrobial resistance profile in 126 strains of Escherichia coli isolated from swabs obtained from fragments of the small intestines of 235 healthy pigs killed in slaughterhouses in Pernambuco (Brazil) using polymerase chain reaction (PCR), adherence to microplates test and disc diffusion technique. Of the analyzed samples, 88.10% (111/126) were classified in phylogenetic group B1; 4.76% (6/126) in group D; 3.97% (5/126) in group B2 and, 3.17% (4/126) in group A. Antimicrobial resistance rates observed were: lincomycin 100% (126/126), erythromycin 100% (126/126), chlortetracycline 94.44% (119/126), cephalothin 51.59% (65/126), ampicillin 38.89% (49/126), sulfamethoxazole + trimethoprim 37.3% (47/126), ciprofloxacin 19.84% (25/126), norfloxacin 14.29% (18/126), gentamicin 8.73% (11/126) and, chloramphenicol 5.55% (7/126). Multiple antibiotic resistance (MAR) ranged from 0.2 to 0.9. Of the strains tested 46.03% (58/126) produced biofilm, and 99.21% (125/126) of the strains exhibited multi-resistance. Further studies are required to elucidate the importance of each phylogenetic group in pigs and to prevent the propagation of multi-resistant E. coli strains.(AU)

Doenças entéricas de origem bacteriana são frequentes na indústria de suínos, destacando-se a colibacilose, que afeta principalmente leitões e causa grandes danos à indústria suína em todo o mundo. Cento e vinte e seis cepas de Escherichia coli foram isoladas de swabs obtidos de fragmentos de intestino delgado de 235 suínos saudáveis abatidos em matadouros de Pernambuco (Brasil). O objetivo do presente estudo foi analisar filogeneticamente essas cepas, bem como detectar a produção de biofilme e determinar o perfil de resistência antimicrobiana delas, utilizando-se a reação em cadeia da polimerase (PCR), o teste de adesão em microplacas e a técnica de disco-difusão. 88,10% (111/126) das amostras foram classificadas no grupo filogenético B1; 4,76% (6/126) no grupo D; 3,97% (5/126) no grupo B2; e 3,17% (4/126) no grupo A. As taxas de resistência antimicrobiana observadas foram: lincomicina 100% (126/126), eritromicina 100% (126/126), clortetraciclina 94,44% (119/126), cefalotina 51,59% (65/126), ampicilina 38,89% (49/126), sulfametoxazol + trimetoprima 37,3% (47/126), ciprofloxacina 19,84% (25/126), norfloxacina 14,29% (18/126), gentamicina 8,73% (11/126) e cloranfenicol 5,55% (7/126). O índice de resistência múltipla (IRMA) variou de 0,2 a 0,9. Entre as amostras, 46,03% (58/126) produziram biofilme e 99,21% (125/126) foram multirresistentes. São necessários mais estudos para elucidar a importância de cada grupo filogenético em suínos e evitar a propagação de estirpes de E. coli multirresistentes.(AU)

Atividade antimicrobiana in vitro de extratos de plantas do bioma caatinga em isolados de Escherichia coli de suínos / Antimicrobial activity in vitro extracts from caatinga plants in isolated Escherichia coli from pigs

RESUMO A suinocultura é uma atividade pecuária bem consolidada no Brasil. Por outro lado a colibacilose neonatal, cujo patógeno é Escherichia coli, pode diminuir a produtividade nas granjas e causar prejuízos aos produtores. O tratamento baseia-se na utilização de drogas antimicrobianas. Todavia, o uso indiscriminado dessas substâncias tem levado a seleção de cepas resistentes. Diante disso, a busca por alternativas terapêuticas, como as plantas medicinais, tem se tornado cada vez mais comum. Dessa maneira, objetivou-se determinar a atividade antimicrobiana de cinco extratos etanólicos de plantas do bioma caatinga: Amburana cearensis (Fr. Allem) A.C. Smith, Encholirium spectabile Mart., Hymenaea courbaril L, Neoglaziovia variegata Mez e Selaginella convoluta Spring frente a 43 isolados de Eschericha coli coletados de suínos. Para o teste de sensibilidade in vitro foi realizada a técnica da Concentração Bactericida Mínima (CBM) pelo método da microdiluição em microplaca. Os extratos apresentaram atividade antimicrobiana nas seguintes médias 138,75 175,28, 128,36, 127,71 e 129,33 μg/mL, respectivamente. Essa atividade antibacteriana pode estar relacionada a ação de metabólitos secundários presentes nos extratos dessas plantas. Dessa forma, nosso estudo pode contribuir para o desenvolvimento de alternativas terapêuticas no tratamento de infecções, como a colibacilose neonatal em suíno, bem como para o conhecimento acerca das plantas medicinais da Caatinga.

ABSTRACT Swine production is a well-established livestock activity in Brazil. On the other hand, the Neonatal Colibacillosis, whose pathogen is Escherichiacoli, can decrease the productivity on farms and cause losses to producers. The treatment of the disease is based on the use of antimicrobial drugs. However, the free use of these substances has led to the selection of resistant strains. Thus, the search for alternative therapies such as medicinal plants has become becoming increasingly common. In this context, we aimed to determine the antimicrobial activity of ethanol extracts of five plants from the caatinga biome: A. cearensis (Fr. Allem) AC Smith, Encholirium spectabile Mart, Hymenaea courbaril L, Neoglaziovia variegata Mez and Selaginella convoluta Spring in face of isolates of Eschericha coli collected from pigs. For the in vitro susceptibility testing, the method of Minimum Bactericidal Concentration (MBC) was chosen The extracts showed antimicrobial activity in the following averages 138.75 175.28, 128.36, 127.71 and 129.33 mg / mL, respectively. This antibacterial activity could be related to the action of secondary metabolites in the extracts of these plants. Thus, the current study can contribute to the development of alternative therapies for the treatment of infections such as swine Colibacillosis Neonatal, as well as to the knowledge of Caatinga medicinal plants.

Citoinclusão de capa leucocitária e medula óssea de cães: padronização da técnica / Cell block of canine buffy coat and bone marrow in paraffin blocks: technique standardization

A técnica de citoinclusão é amplamente utilizada e reconhecida por profissionais da área da saúde, em particular médicos patologistas, porém as informações sobre a aplicação desse método em medicina veterinária ainda são raras. Análises citológicas de medula óssea e da capa leucocitária (porção do sangue formada por concentrados de leucócitos) são amplamente utilizadas no diagnóstico de patologias de origem neoplásica e não neoplásica e de agentes infecciosos. Embora a importância do uso da técnica seja amplamente reconhecida, não há registro da utilização de amostras citológicas de medula óssea e capa leucocitária na confecção de citoinclusões em blocos de parafina, como meio de diagnóstico no segmento médico veterinário. Assim, este trabalho tem como objetivo elaborar um protocolo de citoinclusão em parafina para amostras citológicas de medula óssea e capa leucocitária de cães. Foram submetidas à técnica de citoinclusão 110 amostras de capa leucocitária e 44 de medula óssea de cães portadores ou não de enfermidade sistêmica, sendo que em 68% destas, tanto para a capa leucocitária quanto para a medula óssea, as amostras se mostraram viáveis. A utilização do álcool 95% como fixador e de etapas no processamento histológico de 20 minutos (álcool absoluto, xilol e parafina, três banhos cada) foi crucial para a qualidade dos cortes histológicos e para a análise microscópica dos espécimes corados pela hematoxilina-eosina. A separação mecânica da capa leucocitária e a centrifugação do aspirado de medula óssea foram eficientes e de baixo custo no preparo das citoinclusões. Ressalta-se a importância na padronização da técnica de citoinclusão, em particular para amostras de capa leucocitária e medula óssea, visando à obtenção de espécimes de qualidade independentemente das limitações de equipamentos...

The cell block technique is widely used and recognized by health professionals, but lacks in information regarding the specific contribution of this method to veterinary medicine. The cytology of bone marrow and buffy coat (cellular portion of the hole blood) are widely used in the diagnosis of neoplastic and non-neoplastic diseases, and also for the detection of infectious agents. Although the importance of these samples is widely recognized, there is no information about the use of buffy coat and bone marrow samples in the cell block procedure among the research material used for this paper. This work aims for the cell block standardization for canine buffy coat and bone marrow samples. We collected 110 buffy coat samples and 44 bone marrow samples for the cell block preparation, and 68.2% of buffy coat and bone marrow proved to be viable at the end of the procedure. The 95% ethanol fixatives along with the 20 minute processing steps (absolute ethanol, xilol and paraffin, 3 of each) were crucial for the quality of the material both in microtomy and optical microscopy. Mechanical separation of the buffy coat proved to be easy and cheap and was used to compose the cell block technique. In this research we emphasized the importance of cell block standardization in order to develop and easy, inexpensive and reproducible method, regardless of any of the professionals' limitations...