Jersey steer ruminal papillae histology and nutrigenomics with diet changes

The transition from a high forage to a high concentrate diet is an important milestone for beef cattle moving from a stocker system to the feedlot. However, little is known about how this transition affects the rumen epithelial gene expression. This study assessed the effects of the transition from a high forage to a high concentrate diet as well as the transition from a high concentrate to a high forage diet on a variety of genes as well as ruminal papillae morphology in rumen fistulated Jersey steers. Jersey steers (n = 5) were fed either a high forage diet (80% forage and 20% grain) and transitioned to a high concentrate diet (20% forage and 80% grain) or a high concentrate diet (40% forage and 60% grain) and transitioned to a high forage diet (100% forage). Papillae from the rumen were collected for histology and RT‐qPCR analysis. Body weight had a tendency for significant difference (p = .08). Histological analysis did not show changes in papillae length or width in steers transitioning from a high forage to a high concentrate diet or vice versa (p > .05). Genes related to cell membrane structure (CLDN1, CLDN4, DSG1), fatty acid metabolism (CPT1A, ACADSB), glycolysis (PFKL), ketogenesis (HMGCL, HMGCS2, ACAT1), lactate/pyruvate (LDHA), oxidative stress (NQO1), tissue growth (AKT3, EGFR, EREG, IGFBP5, IRS1) and the urea cycle (SLC14A1) were considered in this study. Overall, genes related to fatty acid metabolism (ACADSB) and growth and development (AKT3 and IGFBP5) had a tendency for a treatment × day on trial interaction effect. These profiles may be indicators of rumen epithelial adaptations in response to changes in diet. In conclusion, these results indicate that changes in the composition of the diet can alter the expression of genes with specific functions in rumen epithelial metabolism.     

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Effect of elevated carbon dioxide concentration and root restriction on net photosynthesis, water relations and foliar carbohydrate status of loblolly pine seedlings

To determine the effects of CO(2)-enriched air and root restriction on photosynthetic capacity, we measured net photosynthetic rates of 1-year-old loblolly pine seedlings grown in 0.6-, 3.8- or 18.9-liter pots in ambient (360 micro mol mol(-1)) or 2x ambient CO(2) (720 micro mol mol(-1)) concentration for 23 weeks. We also measured needle carbohydrate concentration and water relations to determine whether feedback inhibition or water stress was responsible for any decreases in net photosynthesis. Across all treatments, carbon dioxide enrichment increased net photosynthesis by approximately 60 to 70%. Net photosynthetic rates of seedlings in the smallest pots decreased over time with the reduction occurring first in the ambient CO(2) treatment and then in the 2x ambient CO(2) treatment. Needle starch concentrations of seedlings grown in the smallest pots were two to three times greater in the 2x ambient CO(2) treatment than in the ambient CO(2) treatment, but decreased net photosynthesis was not associated with increased starch or sugar concentrations. The reduction in net photosynthesis of seedlings in small pots was correlated with decreased needle water potentials, indicating that seedlings in the small pots had restricted root systems and were unable to supply sufficient water to the shoots. We conclude that the decrease in net photosynthesis of seedlings in small pots was not the result of CO(2) enrichment or an accumulation of carbohydrates causing feedback inhibition, but was caused by water stress.     

Additive and synergistic antifungal effects of copper and phenolic extracts from grape cane and apples

Background

Organic viticulture seeks sustainable alternatives for eco-toxic copper fungicides to control downy mildew caused by Plasmopara viticola. (Poly)phenol-rich extracts of agricultural byproducts are known to possess antifungal activity, but high production costs often limit their actual implementation.

Results

We developed and produced novel ligninsulfonate-based grape cane extract (GCE) formulations and an apple extract on a pilot plant scale, including a detailed (poly)phenol characterization by high-performance liquid chromatography photodiode array mass spectrometry (HPLC-PDA-MS). Our GCE formulations alone reduced downy mildew disease severity in greenhouse trials by 29%–69% in a dose-dependent manner, whereas a standard application of the copper-based agent alone reached ~56%. When applied together, disease severity was diminished by 78%–92%, revealing a synergistic effect that depended on the mixture ratio. Combining GCE formulations with the apple extract, additive effects were found (80% disease severity reduction).

Conclusion

The studied plant extracts are proposed to both substitute for and synergistically reinforce copper fungicides in grapevine downy mildew control. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Fumonisins affect the intestinal microbial homeostasis in broiler chickens,predisposing to necrotic enteritis

Fumonisins (FBs) are mycotoxins produced by Fusarium fungi. This study aimed to investigate the effect of these feed contaminants on the intestinal morphology and microbiota composition, and to evaluate whether FBs predispose broilers to necrotic enteritis. One-day-old broiler chicks were divided into a group fed a control diet, and a group fed a FBs contaminated diet (18.6 mg FB1+FB2/kg feed). A significant increase in the plasma sphinganine/sphingosine ratio in the FBs-treated group (0.21 ± 0.016) compared to the control (0.14 ± 0.014) indicated disturbance of the sphingolipid biosynthesis. Furthermore, villus height and crypt depth of the ileum was significantly reduced by FBs. Denaturing gradient gel electrophoresis showed a shift in the microbiota composition in the ileum in the FBs group compared to the control. A reduced presence of low-GC containing operational taxonomic units in ileal digesta of birds exposed to FBs was demonstrated, and identified as a reduced abundance of Candidatus Savagella and Lactobaccilus spp. Quantification of total Clostridium perfringens in these ileal samples, previous to experimental infection, using cpa gene (alpha toxin) quantification by qPCR showed an increase in C. perfringens in chickens fed a FBs contaminated diet compared to control (7.5 ± 0.30 versus 6.3 ± 0.24 log10 copies/g intestinal content). After C. perfringens challenge, a higher percentage of birds developed subclinical necrotic enteritis in the group fed a FBs contaminated diet as compared to the control (44.9 ± 2.22% versus 29.8 ± 5.46%).

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-015-0234-8) contains supplementary material, which is available to authorized users.     

Landscape variation in microarthropod response to calcium addition in a northern hardwood forest ecosystem

Loss of base cations from soils of the northeastern US may adversely influence forest health. A watershed-level calcium (as wollastonite, CaSiO₃) addition experiment was initiated at the Hubbard Brook Experimental Forest, NH, USA, in fall 1999 to examine responses of forest ecosystem structure and function to restoration of exchangeable Ca that was lost over previous decades. We quantified the response of soil microarthropods to Ca addition as part of this larger study, and we also quantified microarthropod response to smaller scale (1×2 m plots) wollastonite additions within one site in an untreated reference watershed. We observed a small increase in pH in the surface organic horizon, accompanied by a decline in microarthropod abundance per gram organic matter three years following wollastonite application. However, responses varied among microarthropod groups, across years, and among study plots that were distributed along an elevation gradient in treatment and reference watersheds. Collembola declined in the treatment relative to the reference watershed in the second year but recovered in the third year following wollastonite application, whereas oribatid, prostigmatid, and mesostigmatid mites all declined in the treatment relative to the reference watershed by the third year following treatment. The largest treatment responses were observed in two base-poor hardwood stands, whereas at a slightly less poor hardwood site we found the least abundant and least variable microarthropod populations, and no response was observed to either the watershed or the plot-level treatments. Our results demonstrate that soil microarthropods are sensitive to relatively small changes in soil Ca, but that landscape position must be considered in testing responses of these soil biota to soil base status.     

Solar UVB response of bioactives in strawberry (Fragaria × ananassa Duch. L.): a comparison of protected and open-field cultivation

Strawberries (Fragaria × ananassa Duch. cvs. Everest, Elsanta) were grown in a tunnel covered with two films, which were distinguished in their ultraviolet transparency, as well as under open-field conditions. One applied film was not transparent for UVB radiation, and the second film transmitted 70% of UVB radiation. During the present study, the nutritional value and quality parameters of the fruits were evaluated. Strawberries were UV-unresponsive in view of the content of ascorbic acid and sum parameters like total anthocyanins and antioxidant capacity measured with TEAC (trolox equivalent antioxidant capacity), ORAC (oxygen radical absorbance capacity) and total phenols. These parameters were mainly affected by sampling date and cultivar. However, HPLC analysis showed that individual phenolics were affected in the absence of UV radiation. The content of the anthocyanin cyanidin 3-glucoside and the flavonols quercetin 3-glucuronide and kaempferol 3-glucoside was decreased in the fruits grown under UV blocking film compared to open-field grown strawberries. By means of the UV transparent film the content of the mentioned flavonoids could be enhanced up to similar amounts like in open-field grown strawberries. All other phenolics were not consistently affected by UV radiation. This result was independent of cultivar.     

Soil CO2 flux from a norfolk loamy sand after 25 years of conventional and conservation tillage

Tillage affects the ability of coarse-textured soils of the southeastern USA to sequester C. Our objectives were to compare tillage methods for soil CO₂ flux, and determine if chemical or physical properties after 25 years of conventional or conservation tillage correlated with flux rates. Data were collected for several weeks during June and July in 2003, October and November in 2003, and April to July in 2004 from a tillage study established in 1978 on a Norfolk loamy sand (fine-loamy, kaolinitic, thermic Typic Kandiudults). Conventional tillage consisted of disking to a depth of approximately 15 cm followed by smoothing with an S-tined harrow equipped with rolling baskets. Conservation tillage consisted of direct seeding into surface residues. Flux rates in conservation tillage averaged 0.84 g CO₂ m⁻² h⁻¹ in Summer 2003, 0.36 g CO₂ m⁻² h⁻¹ in Fall 2003, 0.46 g CO₂ m⁻² h⁻¹ in Spring 2004, and 0.86 g CO₂ m⁻² h⁻¹ in Summer 2004. Flux rates from conventional tillage were greater for most measurement times. Conversely, water content of the surface soil layer (6.5 cm) was almost always higher with conservation tillage. Soil CO₂ flux was highly correlated with soil water content only in conventional tillage. In conservation tillage, no significant correlations occurred between soil CO₂ flux and soil N, C, C:N ratio, pH, bulk density, sand fraction, or clay fraction of the surface 7.5 cm. In conventional tillage, sand fraction was positively correlated, while bulk density and clay fraction were negatively correlated with soil CO₂ flux rate, but only when the soil was moist. Long-term conservation tillage management resulted in more uniform within- and across-season soil CO₂ flux rates that were less affected by precipitation events.