Combination effects of phytonutrient pellet and lemongrass (Cymbopogon citratus) powder on rumen fermentation efficiency and nutrient degradability using in vitro technique

Phytonutrients (PTN) namely saponins (SP) and condensed tannins (CT) have been demonstrated to assess the effect of rumen fermentation and methane mitigation. Phytonutrient pellet containing mangosteen, rambutan, and banana flower (MARABAC) and lemongrass including PTN, hence these plant-phytonutrients supplementation could be an alternative plant with a positive effect on rumen fermentation. The aim of this experiment was to evaluate the effect of supplementation of MARABAC and lemongrass (Cymbopogon citratus) powder on in vitro fermentation modulation and the ability to mitigate methane production. The treatments were arranged according to a 3 × 3 Factorial arrangement in a completely randomized design. The two experimental factors consisted of MARABAC pellet levels (0%, 1%, and 2% of the total substrate) and lemongrass supplementation levels (0%, 1%, and 2% of the total substrate). The results of this study revealed that supplementation with MARABAC pellet and lemongrass powder significantly improved gas production kinetics (P < 0.01) and rumen fermentation end-products especially the propionate production (P < 0.01). While rumen methane production was subsequently reduced by both factors. Additionally, the in vitro dry matter degradability (IVDMD) and organic matter degradability (IVOMD) were greatly improved (P < 0.05) by the respective treatments. MARABAC pellet and lemongrass powder combination showed effective methane mitigation by enhancing rumen fermentation end-products especially the propionate concentration and both the IVDMD and IVOMD, while mitigated methane production. The combined level of both sources at 2% MARABAC pellet and 2% lemongrass powder of total substrates offered the best results. Therefore, MARABAC pellet and lemongrass powder supplementation could be used as an alternative source of phytonutrient in dietary ruminant.

Comparison of forages’ digestion levels for different in vitro digestion techniques in horses

BACKGROUND

Forages are widely used in horse diets. Different in vitro techniques are being tried to determine the fermentation levels of forages in the horse digestive tract.

OBJECTIVES

This study aimed to evaluate the digestion levels of four dry forages commonly used in horse nutrition: alfalfa herbage, meadow hay, wheat straw, and Italian ryegrass. In vitro total digestion (TDT), in vitro Sunvold-large intestine digestion (SDT) and in vitro Menke-large intestine digestion (MDT) techniques were compared.

METHODS

The study determined in vitro true dry matter digestion (T-DMD), in vitro true organic matter digestion (T-OMD) and in vitro true neutral detergent fibre digestion (T-NDFD). Additionally, concentrations of straight short-chain fatty acids (SCFAs; acetic acid - AA, propionic acid , butyric acid, and valeric acid ) and branched short-chain fatty acids (BSCFA) were assessed.

RESULTS

The highest in vitro T-DMD, T-OMD and T-NDFD values were determined by the in vitro TDT for the four forages (p < 0.05). In vitro T-DMD and T-OMD values of alfalfa herbage were higher than those of Italian ryegrass, meadow hay and wheat straw in the in vitro TDT (p < 0.001). In addition, in vitro T-DMD and T-OMD values of alfalfa herbage in the in vitro SDT were higher than those of meadow hay and wheat straw (p < 0.001). In the in vitro TDT, the molarity of AA, total SCFA and BSCFA in the digestion fluid of alfalfa herbage was higher than those of other forages (p < 0.05).

CONCLUSION

The in vitro total enzymatic + fermentative digestion technique for horse forages revealed higher values than the in vitro fermentative digestion techniques. In general, the higher the non-structural carbohydrate and crude protein contents in the forage, the higher the results of the in vitro TDT compared to the other techniques.

Organoids: a promising new in vitro platform in livestock and veterinary research

Organoids are self-organizing, self-renewing three-dimensional cellular structures that resemble organs in structure and function. They can be derived from adult stem cells, embryonic stem cells, or induced pluripotent stem cells. They contain most of the relevant cell types with a topology and cell-to-cell interactions resembling that of the in vivo tissue. The widespread and increasing adoption of organoid-based technologies in human biomedical research is testament to their enormous potential in basic, translational- and applied-research. In a similar fashion there appear to be ample possibilities for research applications of organoids from livestock and companion animals. Furthermore, organoids as in vitro models offer a great possibility to reduce the use of experimental animals. Here, we provide an overview of studies on organoids in livestock and companion animal species, with focus on the methods developed for organoids from a variety of tissues/organs from various animal species and on the applications in veterinary research. Current limitations, and ongoing research to address these limitations, are discussed. Further, we elaborate on a number of fields of research in animal nutrition, host-microbe interactions, animal breeding and genomics, and animal biotechnology, in which organoids may have great potential as an in vitro research tool.

Assessment of erythrocyte damage and in-line pressure changes associated with simulated transfusion of canine blood through microaggregate filters

OBJECTIVE

To determine whether passage of whole blood through a microaggregate filter by use of a syringe pump would damage canine erythrocytes.

SAMPLE

Blood samples obtained from 8 healthy client-owned dogs.

PROCEDURES

Whole blood was passed through a standard microaggregate filter by use of a syringe pump at 3 standard administration rates (12.5, 25, and 50 mL/h). Prefilter and postfilter blood samples were collected at the beginning and end of a simulated transfusion. Variables measured at each time point included erythrocyte osmotic fragility, mean corpuscular fragility, RBC count, hemoglobin concentration, RBC distribution width, and RBC morphology. In-line pressure when blood passed through the microaggregate filter was measured continuously throughout the simulated transfusion. After the simulated transfusion was completed, filters were visually analyzed by use of scanning electron microscopy.

RESULTS

Regardless of administration rate, there was no significant difference in mean corpuscular fragility, RBC count, hemoglobin concentration, or RBC distribution width between prefilter and postfilter samples. Additionally, there were no differences in in-line pressure during the simulated transfusion among administration rates. Echinocytes were the erythrocyte morphological abnormality most commonly observed at the end of the transfusion at administration rates of 12.5 and 25 mL/h.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that regardless of the administration rate, the microaggregate filter did not alter fragility of canine RBCs, but may have altered the morphology. It appeared that the microaggregate filter would not contribute to substantial RBC damage for transfusions performed with a syringe pump.

Assessment of anoxia tolerance and photoperiod dependence of GABAergic polarity in the pond snail Lymnaea stagnalis

The pond snail Lymnaea stagnalis is reported to be anoxia-tolerant and if the tolerance mechanism is similar to that of the anoxia-tolerant painted turtle, GABA should play an important role. A potentially confounding factor investigating the role of GABA in anoxia tolerance are reports that GABA has both inhibitory and excitatory effects within L. stagnalis central ganglion. We therefore set out to determine if seasonality or photoperiod has an impact on: 1) the anoxia-tolerance of the intact pond snail, and 2) the response of isolated neuroganglia cluster F neurons to exogenous GABA application. L. stagnalis maintained on a natural summer light cycle were unable to survive any period of anoxic exposure, while those maintained on a natural winter light cycle survived a maximum of 4h. Using intracellular sharp electrode recordings from pedal ganglia cluster F neurons we show that there is a photoperiod dependent shift in the response to GABA. Snails exposed to a 16h:8h light:dark cycle in an environmental chamber (induced summer phenotype) exhibited hyperpolarizing inhibitory responses and those exposed to a 8h:16h light:dark cycle (induced winter phenotype) exhibited depolarizing excitatory responses to GABA application. Using gramicidin-perforated patch recordings we also found a photoperiod dependent shift in the reversal potential for GABA. We conclude that the opposing responses of L. stagnalis central neurons to GABA results from a shift in intracellular chloride concentration that is photoperiod dependent and is likely mediated through the relative efficacy of cation chloride co-transporters. Although the physiological ramifications of the photoperiod dependent shift are unknown this work potentially has important implications for the impact of artificial light pollution on animal health.

In vitro passages impact on virulence of Saprolegnia parasitica to Atlantic salmon, Salmo salar L. parr

The effect of serial in vitro subculturing on three pathogenic strains of Saprolegnia parasitica was investigated. The isolates were passed through Atlantic salmon, Salmo salar L. parr, and then re-isolated as single spore colonies. All strains caused infection. The isolate obtained from diseased fish served as a virulent reference culture and was designated 'AP' ('activated through passage'). Successive subculturing was made by obtaining an inoculum from AP to produce the 2nd subculture and then passaged to the 3rd subculture (from the 2nd), until the 15th passage was obtained. Spores used to produce storage cultures were collected at passages 5, 10 and 15. The different passages of each strain were used to artificially infect Atlantic salmon parr. Morphological characterization of growth patterns was performed to observe differences occurring due to serial in vitro subculturing. Two of the strains declined in virulence after 15 successive in vitro subcultures, whereas one did not. This study is the first to investigate attenuation of virulence in Saprolegnia and whether or not isolates of S. parasitica should be passed through the fish host prior to challenge experiments. It reveals that some strains degenerate more rapidly than others when subjected to successive in vitro subculturing on glucose-yeast extract.