Effects of Pre-Stratification Storage Conditions on Black Walnut Seed Post-Stratification Germination Capacity

The objective of this work was to quantify changes in the germination capacity of Juglans nigra seeds following storage and then artificial stratification. Seeds were stored at 5 and –20 °C under 5% and 14% internal moisture content (IMC) for 0, 8, 10, and 12 months under conditions with oxygen or under vacuum. Germination percentage (GP) was affected by storage temperature, IMC, and storage period. Seeds stored with 5% IMC succeeded in germinating regardless of the temperature. Seeds stored with 14% IMC did not germinate (–20 °C) or germinated during storage (5 °C). The GP was reduced with the time of storage in seeds at –20 °C and 5% IMC and this effect was avoided in storage under vacuum. In conclusion, the germination capacity of black walnut seeds did not change for up to 12 months at low above-zero temperature and low IMC (5 °C, 5% IMC), being the most cost-effective alternative for long-term storage of black walnut seeds in commercial nurseries. Vacuum storage avoided the decrease of around 50% in average germination capacity of seeds stored for a year at –20 °C.     

Uptake and metabolism as mechanisms of selective herbicidal activity of the 1,2,4-triazolo[1,5-a] pyrimidines

In order to identify the factors providing the triazolopyrimidines with a wide range of selectivity amongst agriculturally important plant species, studies were made on the uptake and metabolism of a representative compound, N-(2,6-dichlorophenyl)-5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine- 2-sulfonamide. This compound is much more phytotoxic to dicots than to monocots. Experiments showed that variations in leaf morphologies and geometries relative to spray applications resulted in different herbicide dosages applied to plant species used in selectivity evaluations. However, this parameter did not have a statistically significant correlation to herbicide selectivity measurements. Characterization of the metabolic pathways showed that the major herbicide metabolites involved methyl hydroxylation or hydroxylation of the aniline ring followed by glucose conjugation. Since these metabolites were not exclusive to either monocots or dicots, herbicide selectivity does not appear dependent on the pathway of metabolism. Studies on the kinetics of metabolism suggest instead that metabolic rate was important. Monocots metabolized the herbicide rapidly and generally were tolerant while the opposite was true of dicots.     

Endometrial Adenocarcinoma and Mucometra in a 6-year-old Alaska Malamute Dog

A 6-year-old female Alaska Malamute dog was presented for evaluation of abdominal enlargement referred by a local veterinarian. On the history, the owner complained of chronic abdominal enlargement initiated more than 4 months ago, reduced appetite, occasional vomiting and general dullness. He also complained of greenish mucous intermittent vaginal discharge starting 10 days ago. The bitch was chronically treated with medroxiprogesterone acetate. A laparatomy was performed and fluid in the abdomen was found and aspirated during the surgery. Also a very fluid-filled distended uterus and a mass in the distal part of the left uterine horn were found. The mass was encapsulated by the omentum, but areas of necrosis and calcification were identified. Histopathological diagnosis was endometrial adenocarcinoma.     

Flash electroretinography in standing horses using the DTL microfiber electrode

Purpose The goal of our study was the evaluation of a practical method for the recording of flash electroretinograms (ERGs) in sedated, standing horses with the DTL? microfiber electrode. Methods The horses were sedated intravenously with detomidine hydrochloride (0.015 mg/kg). The pupil was dilated and the auriculopalpebral nerve was blocked. The ERGs were recorded with the active electrode on the cornea (DTL?), the reference electrode near the lateral canthus, and the ground electrode over the occipital bone. The light intensities of the white strobe light were 0.03 cd·s/m² (scotopic) and 3 cd·s/m² (scotopic and photopic). Photopic and scotopic single flash and flicker responses to Ganzfeld stimulation were recorded. During the 20‐min dark adaptation period the retina was stimulated every 5 min with the 0.03 cd·s/m² single flash. Results The median b‐wave amplitudes and implicit times were 38 µV and 33 ms (photopic cone‐dominated response), 43 µV and 63 ms (5‐min dark adaptation), 72 µV and 89 ms (10 min), 147 µV and 103 ms (15 min), 188 µV and 109 ms (20 min, 0.03 cd·s/m², rod response), and 186 µV and 77 ms (20 min, 3 cd·s/m², maximal combined rod‐cone response). A steady increase in amplitude and implicit time was noted during dark adaptation. No oscillatory potentials could be isolated. Conclusions The use of detomidine hydrochloride sedation and the DTL? microfiber electrode allowed the recording of good quality ERGs. This protocol should permit the detection of functional problems in the retina without the risk involved with general anesthesia.     

Serological response of guinea pigs to oily and aqueous inactivated vaccines containing a Brazilian isolate of the Bovine Viral Diarrhea Virus (BVDV)

Bovine Viral Diarrhea Virus (BVDV) is widespread in cattle in Brazil and research shows its large antigenic variability. Available vaccines are produced with virus strains isolated in other countries and may not be effective. In this study, inactivated vaccines containing the Brazilian BVDV-Ib IBSP11 isolate were developed and tested on 6 groups of 10 guinea pigs (Cavia porcellus). Animals in groups A and C received an aqueous vaccine (aluminum hydroxide); B and D groups received an oily vaccine (Montanide ISA50); Group E positive-control animals were given an imported commercial vaccine with BVDV-Ia Singer; Group F animals were sham vaccinated (negative control). Groups A, B and E received two doses, and Groups C and D, three, every 21 days. Twelve blood samples were taken, at 21-day intervals over 231 days, and evaluated for antibody titer through virus-neutralization (VN), using a homologous strain (IBSP11), and a heterologous strain (BVDV-Ia NADL). Most animals, 42 days following the first dose, seroconverted to both strains and, after the second dose, there was a significant increase of titers in all groups. The oily formulation induced greater response after the third administration. This increase was not observed with the aqueous vaccines, regardless of the virus used in the VN. Antibody decline was more rapid in animals that received aqueous vaccines. The results showed the importance of studying the influence of endemic strains of commercial vaccines, to improve the efficacy of BVD vaccination. Use of the endemic strain in vaccine formulation presented promising results, as well as the use of guinea pigs as a laboratory model.     

Seasonal and temporal changes in species use of the landscape: how do they impact the inferences from multi-scale habitat modeling?

Context

Multi-scale approaches to habitat modeling have been shown to provide more accurate understanding and predictions of species-habitat associations. It remains however unexplored how spatial and temporal variations in habitat use may affect multi-scale habitat modeling.

Objectives

We aimed at assessing how seasonal and temporal differences in species habitat use and distribution impact operational scales, variable influence, habitat suitability spatial patterns, and performance of multi-scale models.

Methods

We evaluated the environmental factors driving brown bear habitat relationships in the Cantabrian Range (Spain) based on species presence records (ground observations) for the period 2000–2010, LiDAR data on forest structure, and seasonal estimates of foraging resources. We separately developed multi-scale habitat models for (i) each season (spring, summer, fall and winter) (ii) two sub-periods with different population status: 2000–2004 (with brown bear distribution restricted to the main population nuclei) and 2005–2010 (with expanding bear population and range); and (iii) the entire 2000–2010 period.

Results

Scales of effect remained considerably stable across seasonal and temporal variations, but not the influence of certain environmental variables. The predictive ability of multi-scale models was lower in the seasons or periods in which populations used larger areas and a broader variety of environmental conditions. Seasonal estimates of foraging resources, together with LiDAR data, appeared to improve the performance of multi-scale habitat models.

Conclusions

We highlight that the understanding of multi-scale behavioral responses of species to spatial patterns that continually shift over time may be essential to unravel habitat relationships and produce reliable estimates of species distributions.

     

Modulation of porcine biotransformation enzymes by anthelmintic therapy with fenbendazole and flubendazole

Fenbendazole (FEN) and flubendazole (FLU) are benzimidazole anthelmintics often used in pig management for the control of nematodoses. The in vivo study presented here was designed to test the influence of FLU and FEN on cytochrome P4501A and other cytochrome P450 (CYP) isoforms, UDP-glucuronosyl transferase and several carbonyl reducing enzymes. The results indicated that FEN (in a single therapeutic dose as well as in repeated therapeutic doses) caused significant induction of pig CYP1A, while FLU did not show an inductive effect towards this isoform. Some of the other hepatic and intestinal biotransformation enzymes that were assayed were moderately influenced by FEN or FLU. Strong CYP1A induction following FEN therapy in pigs may negatively affect the efficacy and pharmacokinetics of FEN itself or other simultaneously or consecutively administered drugs. From the perspective of biotransformation enzyme modulation, FLU would appear to be a more convenient anthelmintic therapy of pigs than FEN.     

Effect of restricted suckling on milk yield,milk composition and udder health in cows and behaviour and weight gain in calves,in dual-purpose cattle in the tropics

The study was conducted to evaluate the effects of restricted suckling (RS) in dual-purpose cows and calves compared to artificial rearing (AR). Twelve Holstein-Zebu cows with calves were assigned to each treatment. Cows were milked once daily in the morning with calves present to stimulate milk let-down. RS calves suckled 30 min after milking and 30 min in the afternoon, whereas AR calves were milk-fed from nipple bottles. The daily saleable milk yield was higher in RS than in AR cows (p < 0.01; 7.44 vs 6.50 kg/day), whereas RS cows had lower milk-fat content (p < 0.001). AR cows had higher California Mastitis Test scores (p < 0.001) and lower lactose content (p < 0.001) compared to RS cows, which indicates an improved udder health in RS cows. AR calves displayed more ‘cross-suck’ during suckling/milk feeding (p < 0.001) and during observations of general behaviour (p < 0.05), and more ‘lick and sniff interior’ during milking (p < 0.05) and suckling/milk feeding (p < 0.01), compared to RS calves. During observations of general behaviour the RS calves were more often observed to ‘walk’ (p < 0.01) and ‘lick self’ (p < 0.05) and less frequently to ‘eat concentrate’ (p < 0.05) than AR calves. Results support the hypothesis that RS increases milk yield, influences milk composition and improves udder health in cows, and decreases abnormal sucking in calves.     

Skin and coat traits in sheep in Brazil and their relation with heat tolerance

The objective of this study was to evaluate and compare physical parameters in groups of sheep with different phenotypic characteristics in the Centre-west region of Brazil. Five groups of sheep, with nine animals per group, were selected, three groups of Santa Inês animals with different coat colours (white, brown and black), one group with crossbred animals (Santa Inês × Bergamasca) and one group with animals of the Bergamasca breed. The following traits were evaluated: coat thickness, number and length of hair, pigmentation level in the coat and the skin as well as the percentage area of sweats glands in the skin tissue, carried out by histological analysis. The number of hairs and the area of sweats glands were not significantly different between the evaluated groups. The Bergamasca breed showed low pigmentation of the skin and long hairs. The levels of pigmentation of the hair and of the skin were highly correlated. Between the Santa Inês groups, the group with white hair showed the better parameters for heat adaptation, while the brown hair group showed the lower heat adaptation when compared with another hair breed groups.