Genome-wide association study provides insights into genes related with horn development in Nelore beef cattle.

The causal mutation for polledness in Nelore (Bos taurus indicus) breed seems to have appeared first in Brazil in 1957. The expression of the polled trait is known to be ruled by a few groups of alleles in taurine breeds; however, the genetic basis of this trait in indicine cattle is still unclear. The aim of this study was to identify genomic regions associated with the hornless trait in a commercial Nelore population.

Effect of distillers feedstuffs and lasalocid on Campylobacter carriage in feedlot cattle.

Campylobacter bacteria are foodborne pathogens that can colonize the gut of food animals. Limited in their ability to ferment sugars, Campylobacter can derive energy for growth via amino acid catabolism. The objectives of the present studies were to test whether supplemental distillers grains containing high amounts of rumen-undegradable intake protein or supplemental lasalocid may, by promoting amino acid flow to the lower bovine gut, increase intestinal carriage of Campylobacter.

Perceptions of veterinarians and producers concerning Johne's disease prevalence and control in US beef cow-calf operations.

Background: Efforts to educate producers and veterinarians in the United States regarding the management, prevention and control of Mycobacterium avium subspecies paratuberculosis (MAP) infection have increased over recent years. While nationwide awareness about MAP infection is improving, current level of awareness among beef producers and veterinarians is largely unknown. This study compares the perceptions of beef producers and veterinarians on the burden of MAP infection in cow-calf herds and on measures to control new infections.

Comparison of calf weaning weight and associated economic variables between beef cows with and without serum antibodies against or isolation from feces of Mycobacterium avium subsp paratuberculosis.

Objective: To compare calf weaning weight and associated economic variables for beef cows with serum antibodies against Mycobacterium avium subsp paratuberculosis (MAP) or from which MAP was isolated from feces with those for cows that were seronegative for antibodies against or culture negative for MAP.

Design: Retrospective study.

Animals: 4,842 beef cows from 3 herds enrolled in the USDA National Johne's Disease Demonstration Herd Project.

Perceptions of veterinarians in bovine practice and producers with beef cow-calf operations enrolled in the US Voluntary Bovine Johne's Disease Control Program concerning economic losses associated with Johne's disease.

This study compares the perceptions of producers and veterinarians on the economic impacts of Mycobacterium avium subspecies paratuberculosis (MAP) infection in cow-calf herds. Questionnaires were mailed to beef producers through the Designated Johne's Coordinators and to veterinarians belonging to a nationwide professional organization. Important components of losses associated with MAP infected cows were used to estimate total loss per infected cow-year using an iterative approach based on collected survey data.

Evolution of the bovine TLR gene family and member associations with Mycobacterium avium subspecies paratuberculosis infection.

Members of the Toll-like receptor (TLR) gene family occupy key roles in the mammalian innate immune system by functioning as sentries for the detection of invading pathogens, thereafter provoking host innate immune responses. We utilized a custom next-generation sequencing approach and allele-specific genotyping assays to detect and validate 280 biallelic variants across all 10 bovine TLR genes, including 71 nonsynonymous single nucleotide polymorphisms (SNPs) and one putative nonsense SNP. Bayesian haplotype reconstructions and median joining networks revealed haplotype sharing between Bos taurus taurus and Bos taurus indicus breeds at every locus, and specialized beef and dairy breeds could not be differentiated despite an average polymorphism density of 1 marker/158 bp.

Microbial fuel cells and microbial ecology: applications in ruminant health and production research.

Microbial fuel cell (MFC) systems employ the catalytic activity of microbes to produce electricity from the oxidation of organic, and in some cases inorganic, substrates. MFC systems have been primarily explored for their use in bioremediation and bioenergy applications; however, these systems also offer a unique strategy for the cultivation of synergistic microbial communities. It has been hypothesized that the mechanism(s) of microbial electron transfer that enable electricity production in MFCs may be a cooperative strategy within mixed microbial consortia that is associated with, or is an alternative to, interspecies hydrogen (H(2)) transfer.

Preliminary investigation of a humoral and cell-mediated immunity ratio for diagnosis of paratuberculosis in beef cattle.

One thousand three hundred and twenty-four adult beef cattle were tested for paratuberculosis using 2 antibody enzyme-linked immunosorbent assays (ELISA), an interferon-gamma (INF-gamma) ELISA, and radiometric bacterial culture of feces from 5 populations. Two populations of cattle (n=226) had data available to calculate a ratio of humoral to cell-mediated immunity based on results from one antibody test and the INF-gamma ELISA. Latent class analysis was used to estimate accuracy of the 4 paratuberculosis assays within a Bayesian framework.

Use of Walpole's solution for treatment of goats with urolithiasis: 25 cases (2001-2006).

Objective: To determine results of ultrasound-guided cystocentesis and percutaneous infusion of Walpole's solution for treatment of male goats with urolithiasis.

Design: Retrospective case series.

Animals: 25 male goats with urolithiasis treated with Walpole's solution.

Assessment of clinical reasoning skills in veterinary students prior to and after the clinical year of training.

Objective: To examine the effect of various clinical tracks within the veterinary medical clinical curriculum at Texas A&M University on clinical diagnostic proficiency as determined by pre- and post-training assessment. We expected that the clinical track chosen by the student would impact their measured outcome with bias toward higher scores in their chosen field.

Design: Prospective cohort study.

Assessing familial aggregation of paratuberculosis in beef cattle of unknown pedigree.

The objective of this study was to assess genetic similarity of beef cattle using microsatellite markers and to use this information to describe familial aggregation of paratuberculosis test results in Texas beef cattle. Paratuberculosis testing was performed on 2622 adult beef cattle using two commercially available serum ELISAs and radiometric fecal culture. Pedigree records were collected for registered purebred herds and herds with sufficiently detailed production records to identify parent-offspring pairs.

Familial associations with paratuberculosis ELISA results in Texas Longhorn cattle.

The objective of this cross-sectional study was to estimate familial associations with paratuberculosis ELISA status in beef cattle. Texas Longhorn cattle (n=715) greater than 2years of age were sampled for paratuberculosis testing using ELISA and fecal culture. Diagnostic test results were indicative of substantial numbers of false-positive serological reactions consistent with environmental exposure to non-MAP Mycobacterium spp.

Contribution of environmental mycobacteria to false-positive serum ELISA results for paratuberculosis.

Objective: To evaluate the effect of exposure to environmental mycobacteria on results of 2 commercial ELISAs for paratuberculosis in cattle.

Design: Experimental trial.

Animals: 19 weaned crossbred beef calves.

Protothecal enteritis as a cause of protein-losing enteropathy in a bull.

Prototheca spp are achlorophyllic saprophytic algae found in wastewater, sewage, agricultural waste, and possibly elsewhere in the environment. Infections with these organisms have been reported in cattle, humans, and dogs; affected cattle commonly develop mastitis. A 5-year-old Brahman-cross bull was evaluated because of a history of diarrhea and weight loss.