Prevalence of antibodies against Toxoplasma gondii among Brazilian white-eared opossums (Didelphis albiventris)

Considering that Toxoplasma gondii is a parasite of global importance which affects several animal species including humans, the current study aimed to investigate the prevalence of antibodies against T. gondii among 72 white-eared opossums (Didelphis albiventris) from Botucatu Municipality (22°53'S 48°26'W), S?o Paulo State, Brazil. The investigation was carried out from January 2008 to December 2009, when the animals had their blood samples collected and subjected to the modified agglutination test (MAT); 12 specimens had brain samples bioassayed in mice. Seroprevalence was 5.5% (n=4) and bioassays were negative. Older animals had higher prevalence of antibodies against T. gondii. Opossums in closer contact with the urban environment are likely more exposed to T. gondii than animals from the sylvatic environment.     

A multiple-phenotype imputation procedure as a method for prediction of cheese-making efficiency in Spanish Assaf sheep

Sheep milk is mainly intended to manufacture a wide variety of high-quality cheeses. The ovine cheese industry would benefit from an improvement, through genetic selection, of traits related to the milk coagulation properties (MCPs) and cheese yield-related traits, broadly denoted as “cheese-making traits.” Considering that routine measurements of these traits needed for genetic selection are expensive and time-consuming, this study aimed to evaluate the accuracy of a cheese-making phenotype imputation method based on the information from official milk control records combined with the pH of the milk. For this study, we analyzed records of milk production traits, milk composition traits, and measurements of cheese-making traits available from a total of 1,145 dairy ewes of the Spanish Assaf sheep breed. Cheese-making traits included five related to the MCPs and two cheese yield-related traits. The milk and cheese-making phenotypes were adjusted for significant effects based on a general linear model. The adjusted phenotypes were used to define a multiple-phenotype imputation procedure for the cheese-making traits based on multivariate normality and Markov chain Monte Carlo sampling. Five of the seven cheese-making traits considered in this study achieved a prediction accuracy of 0.60 computed as the correlation between the adjusted phenotypes and the imputed phenotypes. Particularly the logarithm of curd-firming time since rennet addition (logK₂₀) (0.68), which has been previously suggested as a potential candidate trait to improve the cheese ability in this breed, and the logarithm of the ratio between the rennet clotting time and the curd firmness at 60 min (logRCT/A60) (0.65), which has been defined by other studies as an indicator trait of milk coagulation efficiency. This study represents a first step toward the possible use of the phenotype imputation of cheese-making traits to develop a practical methodology for the dairy sheep industry to impute cheese-making traits only based on the analysis of a milk sample without the need of pedigree information. This information could be also used in future planning of specific breeding programs considering the importance of the cheese-making efficiency in dairy sheep and highlights the potential of phenotype imputation to leverage sample size on expensive, hard-to-measure phenotypes.     

Pharmacokinetics and clinical effects of xylazine and dexmedetomidine in horses recovering from isoflurane anesthesia

This study determined the pharmacokinetics and compared the clinical effects of xylazine and dexmedetomidine in horses recovering from isoflurane anesthesia. Six healthy horses aged 8.5 ± 3 years and weighing 462 ± 50 kg were anesthetized with isoflurane for 2 hr under standard conditions on two occasions one-week apart. In recovery, horses received 200 μg/kg xylazine or 0.875 μg/kg dexmedetomidine intravenously and were allowed to recover without assistance. These doses were selected because they have been used for postanesthetic sedation in clinical and research studies. Serial venous blood samples were collected for quantification of xylazine and dexmedetomidine, and the pharmacokinetic parameters were calculated. Two individuals blinded to treatment identity evaluated recovery quality with a visual analog scale. Times to stand were recorded. Results (mean ± SD) were compared using paired t tests or Wilcoxon signed-ranked test with p < .05 considered significant. Elimination half-lives (62.7 ± 21.8 and 30.1 ± 8 min for xylazine and dexmedetomidine, respectively) and steady-state volumes of distribution (215 ± 123 and 744 ± 403 ml/kg) were significantly different between xylazine and dexmedetomidine, whereas clearances (21.1 ± 17.3 and 48.6 ± 28.1 ml/minute/kg), times to stand (47 ± 24 and 53 ± 12 min) and recovery quality (51 ± 24 and 61 ± 22 mm VAS) were not significantly different. When used for postanesthetic sedation following isoflurane anesthesia in healthy horses, dexmedetomidine displays faster plasma kinetics but is not associated with faster recoveries compared to xylazine.     

Brain anatomy of two-toed sloth (Choloepus didactylus,Linnaeus, 1758): A comparative gross anatomical study of extant xenarthrans

The neural system plays an important role in understanding some features of animals. Anatomical complexity correlates with the increase of functional capacity. Xenarthrans include anteaters (Vermilingua), armadillos (Cingulata) and sloths (Folivora). This group is the base of eutherian mammals, and understanding the anatomy of its neural system could provide data for functional and evolutionary interpretations. The gross anatomy of the xenarthran brain is recorded. Four extant families of Pilosa and two families of Cingulata were sampled. Usual dissection procedures were used, and the brains were analysed macroscopically. The brain of two-toed sloth, three-toed sloth, six-banded armadillo, giant anteater and collared anteater are gyrencephalic. Pygmy anteater, nine-banded armadillo, great long-nosed armadillo, southern naked-tailed armadillo and giant armadillo are lissencephalic. In most species, the rhinal fissure presents two segments, rostral and caudal (except in Vermilingua and three-toed sloth). The diencephalon and brainstem present similar anatomy. The cerebellum is wide and presents four lobes (rostral, central, caudal and floccular). Its average volume is 12.16% (Folivora), 14.26% (Vermilingua) and 18.61% (Cingulata). Among these groups, there is a statistical difference between Folivora/Cingulata concerning the cerebellum average. The general pattern of the brain of the xenarthrans is similar to that of other mammals.     

Manganese foliar supplementation impacts rice yield in tropical lowlands

Abstract

The aim of this work was to evaluate manganese (Mn) sources and levels effects in irrigated rice production in central Brasil (tropical lowlands of Tocantins state). The experiment was conducted in a 5x5?+?1 factorial scheme, five Mn sources and five levels (0.5; 1.0; 1.5; 2.0; and 2.5?kg ha^?1), applied in induction of tillering of rice plants, plus a control without treatment, and Mn content in leaves (mg kg^?1), number of panicles per area (m²), hundred grains weight (g), intact grains (%), and grain yield (kg ha^?1) were analyzed. Treatments with Mn-carbonate source got the best results and this source at the level of 1.5?kg ha^?1 provided the highest yield: 7,375?kg ha^?1. Higher values were obtained with the application of 1.0 to 1.5?kg ha^?1 of Mn, except for the intact grains where the best means were obtained at 2.5?kg ha^?1.     

Effect of seed phosphorus concentration on nodulation and growth of three common bean cultivars

Abstract

An experiment was conducted in the greenhouse to evaluate the effects of seed phosphorus (P) concentration on growth, nodulation, and nitrogen (N) and P accumulation of three common bean (Phaseolus vulgaris L.) cultivars. Seeds were produced under low or high soil P levels, and soaked, or not, in 200 mM KH₂PO₄ solution. The experiment had a 3×3×2×2 factorial block design: three cultivars (ICA Col 10103, Carioca and Honduras 35), three levels of applied P (15, 30 and 45 mg P kg^?1 soil), two native seed P concentrations, and two seed soaking treatments. Plants were harvested at flowering. Soaked seeds increased the number, dry mass and P content of nodules, but did not affect plant growth. Plants originated from seeds with high native P concentration presented higher shoot dry mass and nodule number and mass at every soil P level, and were less responsive to increased soil P supply, than plants from low seed P. In plants from seeds with high P, soil P levels did not alter significantly root dry mass, while in plants from seeds with low P bean cultivars expressed wider differences in root dry mass. The genotypic variability of nodulation was influenced by soil P levels and seed P concentration. Both higher soil or seed P supply enhanced N and P accumulation in shoots. These results indicate that a high seed P concentration produces plants less dependent on soil P supply, and can enhance nodulation and N₂ fixation of common bean. Seed P supply affected the cultivar performance, and should be considered in evaluation of bean genotypes.     

Quantification of loss in oilseed rape yield caused by delayed sowing date in a Mediterranean environment

ABSTRACT

Rapeseed acreage has been increasing fast in the last few decades and cultivated areas have expanded into lower latitudes because of the high value of its seed. This work evaluates the effect of date of sowing and nitrogen (N) fertilization on crop productivity and N use efficiency in a Mediterranean environment. The experiment was arranged in a split-plot design with the dates of sowing as the main-plots and N rates the sub-plots. Rapeseed recovered 128 to 212 kg N hm^-2 before top-dress N application in late winter if sown before the last week of September. Seed yield was very dependent on the date of sowing, varying from 3.4 to 6.2 Mg hm^-2 on the first sowing date in September to 0.3 to 1.0 Mg hm^-2 on the last sowing date in November. The daily loss in seed production was 68.9 kg hm^-2 (or 482.3 kg hm^-2 per week) or 1.53 % (or 10.7 % per week). N rate significantly increased seed yield within each sowing date but did not allow late-sowed plants to regain the productivity levels of those sown earlier. Apparent N recovery and agronomic N efficiency were particularly dependent on the growing conditions associated to different sowing dates.     

Five-year survey uncovers extensive diversity and temporal fluctuations among fusarium head blight pathogens of wheat and barley in Brazil

We conducted a five-year survey (2011–2015) of barley and wheat fields in Paraná state, Brazil, obtaining 754 Fusarium isolates from spikes with fusarium head blight (FHB)-symptoms. Multilocus genotyping and TEF-1α gene sequence analyses confirmed the dominance of the F. graminearum species complex (FGSC, 75.7%), but F. poae (11.5%), as well as F. avenaceum and related members of the F. tricinctum species complex (FTSC, 8.1%) appeared as substantial contributors to FHB. Within the FGSC, F. graminearum of the 15-ADON genotype was dominant (63%), followed by F. meridionale of the NIV genotype (23.1%), F. cortaderiae of the NIV (7%) or 3-ADON (2.6%) genotypes, and F. austroamericanum (3.8%) of the 3-ADON genotype. Substantial variation in pathogen composition was observed across years, with F. poae and F. meridionale frequencies significantly elevated in some years. Most F. poae strains produced DAS, diANIV, and butenolide, but not neosolaniol, T-2, or HT-2. All FTSC species produced moniliformin. Enniatin production was widespread among FTSC species, with the single F. acuminatum strain found to be the strongest producer of enniatins. Our findings confirm FGSC as a major contributor to FHB and expand considerably our knowledge of the presence, frequency, and conditions under which other pathogens may emerge, altering the spectrum of toxins that may accumulate in grain.