Effects of drought‐stressed temperate forage legumes on the degradation and the rumen microbial community in vitro

According to climate change scenarios, central Europe may expect extending drought periods during summer. Lower water availability may influence the ruminal digestion of individual forage legume species differently. To test this hypothesis, Lotus corniculatus L. (var. Bull), Medicago lupulina L. (var. Ekola), Medicago falcata L. (wild seeds) and Trifolium repens L. (var. Rivendel) were each grown in parallel lots of control and drought‐stressed monocultures. Rainout shelters (installed in May 2011 on a regrowth after first cut until harvest in mid of June) withheld rainfall of 40 mm in the drought stress treatment. Samples of dried (60°C) and milled (5 mm screen) forage legumes were incubated in a simulation experiment using Rusitec to assess drought effects on parameters for microbial metabolism. Degradability of dry matter and organic matter as well as methane production decreased in incubations with drought‐stressed compared to control variants of legume species. Degradability of crude protein, neutral detergent fibre, acid detergent fibre and residual organic matter including non‐fibre carbohydrates and lipids were affected by interactions between drought stress and species. Significant interactions were also found for ammonia concentrations, molar SCFA proportions and the microbial communities. It is concluded that drought stress for growing forage legumes influences their ruminal degradation and fermentation as well as the ruminal microbial communities of Bacteria and Archaea differently in a legume species‐dependent manner.     

Untersuchungen zur Lagerung von Erdbeeren unter Berücksichtigung verschiedener Verpackungsmaterialien

In order to reduce the loss of quality of freshly harvested strawberries during storage, the effects of different packaging materials were examined with regard to storage time and temperature regime (20°C with relative humidity 75%, 4°C with relative humidity 88%). Strawberry containers (500?g) were used differing in form, alignment and number of ventilation openings, top and material. It was found that a drop in temperature to 4°C preserved the quality of strawberries longer in all packaging variants. Nevertheless, the used packaging material had different effects on the quality parameters. The packaging material made of polypropylene, which was closed with a lid and was equipped only with little ventilation openings, yielded the best results, e.?g. the transpiration losses were strongly reduced, thus favouring the preservation of pulp consistency and colour stability of the fruits. On the other hand, the fresh mass during storage was reduced by the materials polyethylenterephthalat, polyactid and groundwood. The quality loss was less dependent on the material, but more dependent on the number of ventilation openings. The results showed that with increasing numbers of ventilation openings the transpiration losses increased and the consistency and colour stability of the fruits decreased. In this context, a strong reduction of pathogenic infestation in relation to the ventilation openings could not be observed. As such, the loss of freshness was lowest with the packaging material of polypropylene, followed by the polyethylenterephthalat, polyactid and groundwood. Moreover, it was found that the kind of packaging material and the ventilation openings had an effect on the amount of pressure marks and the discharge of cell sap of the strawberries. The uneven ground surface of the materials made of polyethylenterephthalat and polyactid increased the punctual pressure on the strawberry fruits, which led to pressure marks and injuries of the fruit surface. Sharp-edged ventilation openings close to the ground surface of these variants favoured injuries and cell sap discharges of the packaging.     

Salicylate and biomass yield,and leaf phenolics of dark-leaved willow (Salix myrsinifolia Salisb.) clones under different cultivation methods after the second cultivation cycle

Willow based herbal products containing salicin and its derivatives can be used to alleviate aches and fevers. To guarantee the high quality of the willow drugs and moderate low cultivation and transportation costs, the willows with high salicylate concentrations are recommended for herbal production. Dark-leaved willow (Salix myrsinifolia Salisb.) with its high salicylate content is a promising source of herbal drugs. In the present study, seven dark-leaved willow clones were cultivated under short-rotation system with a two-year cultivation cycle. The yields of salicylates and biomass, and the concentrations of foliar phenolics were determined after the second cultivation cycle. Willow clones were treated by different cultivation methods, i.e. combinations of mulching (black polythene vs. cutter chip) and fertilisation (0, 25, 150 kg ha^?1, N), with the objective of evaluating the most productive clone and cultivation method for herbal willow production. Furthermore, we compared our results to those obtained after the first cultivation cycle. Results showed that the yields of salicylates and biomass, and the concentrations of all foliar phenolic metabolites varied significantly amongst the clones. Biomass yields and salicylate yield were increased by polythene mulching, but the level of response varied between clones. Fertilisation (only the highest rate) caused an increase in yields, but the effect of fertilisation was smaller than that of mulching. Salicylate yield of most clones was higher than that had been during the previous rotation. Phenolic analyses showed that the concentrations of chlorogenic acid, total p-OH-cinnamic acids and soluble condensed tannins were higher in the willows grown in polythene mulch plots than in willows grown on cutter chip mulched plots. Furthermore, the concentrations of diglucoside of SaOH, salicin, disalicortin 1, disalicortin 2, chlorogenic acid, total chlorogenic acids and total flavonoids were higher in fertilized than in unfertilized willows. Salicortin, which was the most abundant salicylate, and total salicylates were not affected by fertilisation and mulching. The effects of fertilisation and mulching on several phenolics were clone-dependent. In conclusion, after two cultivation cycles, the cultivation methods were not effective in increasing the foliar total salicylate concentration, but rather increased the salicylate yield by enhancing the biomass of the synthesising tissues. Since biomass production was increased by the second cultivation cycle, the cultivation of herbal willows under a two-year cycle is recommended. The highly variable responses of the clones to treatments indicate that profitable willow cultivation for herbal industry is based on the right clone selection.     

Effect of gentamicin on CD3+ T-lymphocyte proliferation for treatment of equine recurrent uveitis: An in vitro study

Objective

The objective of the study was to determine the effect of gentamicin on CD3+ T-lymphocyte proliferation and cell viability using an in vitro cell culture model as a means of investigating the mechanism of action of low-dose intravitreal gentamicin injection.

Animals Studied

Three adult horses with no evidence of ophthalmic or systemic disease.

Procedure

Peripheral blood lymphocytes were treated with gentamicin at concentrations 37.5 μg/mL, 112.5 μg/mL, 187 μg/mL, 375 μg/mL, or 750 μg/mL then stimulated to proliferate with concanavalin A (ConA). 4′,6-diamidino-2-phenylindole (DAPI) and carboxyfluoroscein succinimidyl ester (CSFE) were used as markers of cell viability and cell proliferation, respectively. Following 5-day culture, live cell counts and CSFE fluorescent intensity data were collected via automated cell count and flow cytometry. The experimental design was duplicated using preservative-free gentamicin and a proprietary brand formulation. Statistical analysis was performed using two-way ANOVA with Tukey's multiple comparison test.

Results

No statistically significant comparisons in CD3+ T-lymphocyte live cell counts and geometric mean fluorescent intensity of CSFE were identified between gentamicin concentrations or formulations.

Conclusions

Gentamicin had no effect on equine peripheral blood CD3+ T-lymphocyte cell viability and proliferation in concentrations ranging from “safe” to “retinotoxic” in relation to intravitreal injection volumes. Low-dose intravitreal gentamicin may not suppress the Th1- and Th17-mediated immune response.     

Alterations to the synovial invaginations of the navicular bone are associated with pathology of both the navicular apparatus and distal interphalangeal joint when evaluated using high field MRI

Limited information exists regarding associations between distal interphalangeal joint (DIPJ) abnormalities and synovial invagination changes in the distal sesamoid (navicular) bone. This retrospective, analytical study aimed to measure specific characteristics of the synovial invaginations of the navicular bone to determine whether any single characteristic was associated with abnormalities in the DIPJ or navicular apparatus (NA) using high field MRI and a sample of 200 horses’ feet. The DIPJ and NA were graded independently by three scorers. The grades were averaged, creating a global pathology score for the DIPJ, NA, and synovial invaginations. Higher global scores represented more severe pathology. The number of invaginations, depth of penetration, invagination shape, and cross-sectional area (CSA) of the largest invagination were recorded. Interobserver agreement was measured using Cohen's Kappa. Associations of global scores of the DIPJ and NA with individual invagination characteristics were assessed using linear mixed modeling. A significant relationship was found between the number of invaginations and global DIPJ score, with higher invagination numbers associated with higher DIPJ scores. For invagination depth and CSA, a significant relationship was noted with global scores of both the DIPJ and NA. Reliable relationships between the shape of synovial invaginations and global scores of DIPJ and NA were not found, likely due to poor interobserver scoring (0.305). These findings suggest that primary DIPJ disease and NA pathology should be considered when noticing alterations to navicular synovial invaginations on MRI. This contrasts traditional views that synovial invagination abnormalities are indicative solely of NA pathology.