Detection of a novel chloramphenicol resistance plasmid from "equine" Staphylococcus sciuri

A small chloramphenicol resistance (Cm) plasmid of 4.65 kB could be detected in an "equine" Staphylococcus sciuri-culture. This plasmid, designated as pSC3, was identified by interspecific protoplast transformation. On the basis of restriction endonuclease analyses a detailed restriction map of pSC3 could be constructed. This allowed structural comparisons of pSC3 with Cm-plasmids of other staphylococcal species from infections of humans and animals and identification of pSC3 as a member of the pC 221-family of staphylococcal Cm-plasmids. The pSC3-plasmid encoded an inducible chloramphenicol acetyltransferase as confirmed by enzymatic assays. This enzyme could be demonstrated in cell-free lysates of Cm-induced pSC3-transformants.     

Aroma potential of two bairrada white grape varieties: Maria Gomes and Bical

Maria Gomes and Bical are the main white grape varieties in Portuguese Bairrada Appellation, which represent 80% and 15%, respectively, of white vineyard. To estimate their aroma potentialities, free and potential volatile components from the musts were examined. The free volatile components were extracted using a liquid-liquid continuous method and were analyzed by gas chromatography-mass spectrometry. The potential volatile compounds were determined after elimination of the free components by heat and enzymatic treatments. Principal component analysis was used to establish relations between the compounds and the varieties and also the form (free or in potential). Maria Gomes has 11.5 mg/L volatile compounds, of which 33% are in free form; Bical has 4.4 mg/L volatile compounds, of which 46% are in free form. A total of 59 compounds was identified and quantified. In Maria Gomes, the sum of the terpenoids is within the perception limits for hotrienol (0.21 mg/L) and linalool (0.20 mg/L). In Bical, benzyl alcohol and phenylethylethanol represent 20% of the volatile compounds. Considering that the volatile composition pattern of Maria Gomes and Bical varieties are different, wine-making technologies should be developed specifically for each variety.     

Plasmid-encoded antibiotic resistance in Staphylococcus hyicus

A total of 33 Staphylococcus hyicus-cultures from piglets with exudative epidermatitis were analyzed for the presence of antibiotic resistance plasmids. Four small plasmids encoding resistances to chloramphenicol, macrolide-lincosamide-antibiotics, streptomycin or tetracyclines could be identified in plasmid-curing and plasmid-transformation experiments. For further characterization these plasmids were digested with restriction endonucleases. This led to the construction of a specific restriction map for each of the 4 plasmids. On the basis of their restriction maps, these 4 antibiotic resistance plasmids from "porcine" S. hyicus-cultures were compared with the respective resistance plasmids of other staphylococcal species from infections of humans and animals.     

Fatty acid profile of hair lambs and their crossbreds slaughtered at different weights

This study aims to investigate the effect of breed and slaughter weight on fatty the acid profile of the Longissimus dorsi muscle in lambs. Twenty-four Santa Inês (SI), 24.5 Ile de France × 0.5 Santa Inês (Ile × SI) and 12.5 Texel × 0.5 Santa Inês (Te × SI), slaughtered at different weights (30, 35, 40, and 45 kg), were evaluated. The animals were reared with creep feeding to weaning and were feedlot finished, receiving a diet composed of 30% hay and 70% concentrate. The analyses of fatty acids were carried out on the Longissimus muscle of the 13th rib. The experiment was in a three by four factorial design. The total mean saturated fatty acid level was 44.88%, with 43.30% monounsaturated fats and 1.72% polyunsaturated. The major fatty acids found included oleic (43%), palmitic (22%), and stearic (18%). The concentration of desirable fatty acids varied from 61.56% to 66.78%, with Te × SI (66.78%) having the highest levels (P < 0.05). The slaughter weight affected (P < 0.05) the saturated and unsaturated (both mono and poly) fatty acid profiles. The 35-kg slaughter weight showed the most desirable fatty acid profile. The saturated myristic and stearic fatty acids decreased with an increase in the slaughter weight, but oleic acid increased. In the conditions of the present study, the meat from Santa Ines and Texel × Santa Ines lambs had fatty acid profiles more beneficial for human health due to the higher levels of unsaturated fatty acids.     

Computed Tomography of the Lungs of the Dog by a Six-generation CT Scanner, Intravenous Contrast Medium and Different Windows

Computed tomography (CT) is a modern technique of image diagnosis particularly recommended in human medicine to evaluate the existence of pulmonary pathological changes such as neoplasms, metastasis, interstitial infiltrates, etc. In veterinary medicine, however, few anatomical and clinical CT studies in the dog have used apparatus of the latest generation, including injection of intravenous contrast and application of regional specific CT windows with different window width (WW) and window level (WL) to evaluate the lungs, the pulmonary vessels and the bronchial structures. This methodology allows the obtaining of clear CT images with high capacity of tissue discrimination and different shades of attenuation. In this work we have planned a tomographic study of the lungs of the dog by using a six-generation spiral CT scanner (Toshiba Ex Vision), belonging to the private Medical Institute of Radiology 'Irion' of Porto Alegre, Brazil. Four mixed-breed mature dogs (4–6 years, 15–20 kg) were used, two males and two females. The dogs were anaesthetized and kept in a maximum inspiration when obtaining the images. Dogs were placed in a stretcher in a ventral or sternal recumbency. Previously, the contrast urografin® was injected in the cephalic vein. Different CT windows were applied in order to increase the quality of the images: pulmonary window (WW 928; WL -680), high-resolution pulmonary window (WW 1085; WL -750), and soft tissue window (WW 652; WL -34). The use of intravenous contrast, different CT windows and a modern CT apparatus produced excellent images of the pulmonary parenchyma, the pleural cavity, the pulmonary veins, the lobular rami of the pulmonary artery and the lobular bronchi.     

Multiple-breed genetic inference using heavy-tailed structural models for heterogeneous residual variances

Multiple-breed genetic models recently have been demonstrated to account for the heterogenous genetic variances that exist between different beef cattle breed groups. We extend these models to allow for residual heteroskedasticity (heterogeneous residual variances), specified as a function of fixed effects (e.g., sex, breed proportion, breed group heterozygosity) and random effects such as contemporary groups (CG). We additionally specify the residual distributions to be either Gaussian or based on heavier-tailed alternatives such as the Student's t or Slash densities. For each of these three residual densities using either homoskedastic (homogeneous variance) or heteroskedastic error specifications, we analyzed 22,717 postweaning gain records from a Nelore-Hereford population based on a Markov chain Monte Carlo animal model implementation. The heteroskedastic Student's t error model (with estimated df = 7.33 +/- 0.48) was clearly the best-fitting model based on a pseudo-Bayes factor criterion. Breed group heterozygosity and, to a lesser extent, calf sex seemed to be marginally important sources of residual heteroskedasticity. Specifically, the residual variance in F1 animals was estimated to be 0.70 +/- 0.16 times that for purebreds, whereas the male residual variance was estimated to be 1.13 +/- 0.09 times that for females. The CG effects were important random sources of residual heteroskedasticity (i.e., the coefficient of variation of CG-specific residual variances was estimated to be 0.72 +/- 0.06). Purebred Nelores were estimated to have a larger genetic variance (124.84 +/- 21.75 kg2) compared with Herefords (40.89 +/- 6.70 kg2) under the heteroskedastic Student's t error model; however, the converse was observed from results based on a homoskedastic Student's t error model (46.24 +/- 10.90 kg2 and 60.11 +/- 8.54 kg2, respectively). These results indicate that allowing for robustness to outliers and accounting for heteroskedasticity of residual variances has potentially important implications for variance component and genetic parameter estimates from data on multiple-breed populations.     

The use of ultrasonography in the reproductive evaluation of boars

The objective was to study the use of ultrasound as a complementary test in the breeding soundness evaluation in male pigs and study the pattern of echogenicity of the testicular parenchyma in boars of different racial groups. Twenty‐six adult boars from four different racial groups were used, 10 from the Piau breed (group 1), four from the commercial and finishing group (group 2), six Pietrain breed (group 3) and six from the Duroc breed (group 4). All animals were evaluated for breeding soundness evaluation and the ultrasound examination of the testicles. The groups of animals that were evaluated showed no difference in the main semen parameters that were evaluated, except for the sperm volume, concentration of the ejaculated sperm and the supravital staining; the lowest figures were for the animals from the Piau breed (group 1). In relation to the testicular biometrics, Duroc animals (group 4) had a greater scrotal width compared to the other groups. But when we assessed the intensity of pixels of the testicles, there was a difference between groups. The groups 2 (finishing animals), 3 (Pietrain) and 4 had no difference between themselves. Group 3 had greater pixel intensity in relation to group 1. Of the 26 animals studied, five showed an abnormality during ultrasound evaluation, like hydrocele, hyperechoic mass in the testicular parenchyma, cyst in the head of the epididymis and the presence of fluid in the head and tail of the epididymis. The various animal groups studied did not differ in the principal reproductive parameters evaluated, showing that despite the great variability of reproductive traits between breeds and within the same breed, the breeding soundness evaluation, the more complete it is, is essential for the selection of breeders and the ultrasonography of the reproductive system becomes an important addition in this examination.     

Is single-step genomic REML with the algorithm for proven and young more computationally efficient when less generations of data are present?

Efficient computing techniques allow the estimation of variance components for virtually any traditional dataset. When genomic information is available, variance components can be estimated using genomic REML (GREML). If only a portion of the animals have genotypes, single-step GREML (ssGREML) is the method of choice. The genomic relationship matrix (G) used in both cases is dense, limiting computations depending on the number of genotyped animals. The algorithm for proven and young (APY) can be used to create a sparse inverse of G (GAPY~-1) with close to linear memory and computing requirements. In ssGREML, the inverse of the realized relationship matrix (H⁻¹) also includes the inverse of the pedigree relationship matrix, which can be dense with a long pedigree, but sparser with short. The main purpose of this study was to investigate whether costs of ssGREML can be reduced using APY with truncated pedigree and phenotypes. We also investigated the impact of truncation on variance components estimation when different numbers of core animals are used in APY. Simulations included 150K animals from 10 generations, with selection. Phenotypes (h² = 0.3) were available for all animals in generations 1–9. A total of 30K animals in generations 8 and 9, and 15K validation animals in generation 10 were genotyped for 52,890 SNP. Average information REML and ssGREML with G⁻¹ and GAPY~-1 using 1K, 5K, 9K, and 14K core animals were compared. Variance components are impacted when the core group in APY represents the number of eigenvalues explaining a small fraction of the total variation in G. The most time-consuming operation was the inversion of G, with more than 50% of the total time. Next, numerical factorization consumed nearly 30% of the total computing time. On average, a 7% decrease in the computing time for ordering was observed by removing each generation of data. APY can be successfully applied to create the inverse of the genomic relationship matrix used in ssGREML for estimating variance components. To ensure reliable variance component estimation, it is important to use a core size that corresponds to the number of largest eigenvalues explaining around 98% of total variation in G. When APY is used, pedigrees can be truncated to increase the sparsity of H and slightly reduce computing time for ordering and symbolic factorization, with no impact on the estimates.     

Validation of the BioPRYN enzyme‐linked immunosorbent assay for detection of pregnancy‐specific protein‐B (PSPB) and diagnosis of pregnancy in American bison (Bison bison)

This study assessed the accuracy of the commercial BioPRYN^® ELISA for the detection of pregnancy‐specific protein‐B (PSPB) using a single blood sample to determine pregnancy status in American bison (Bison bison). A total of 49 bison cows were used in the study, and sampled at two time‐points during the gestation period, fall and spring, correlating with early‐ to mid‐term gestation (average 62.9 days post‐mating) and mid‐ to late‐term gestation (average 229.2 days post‐mating), respectively. Sensitivity of the test during early‐ to mid‐term gestation sampling period (fall) was 87.1%, while specificity was 100%; sensitivity of the test during late‐term gestation sampling period (spring) was 96.3%, while specificity remained at 100%. In total, the test showed a total sensitivity of 91.4%, specificity of 100% and total accuracy of 93.8%, similar to domestic cattle. Use of the single‐sample BioPRYN^® ELISA in American Bison for pregnancy diagnosis is economical and practical, minimizing animal handling time, frequency and subsequent stress while providing accurate results for pregnancy diagnosis at 62 days post‐mating. This method should be considered over more traditional pregnancy diagnosis methods for use in managed bison herds.