Mob stocking is a type of livestock management method where high densities of animals are restricted to a small area of grassland for short periods of time (e.g., 12-24 hr.) before being moved to new ...forage. Use of mob stocking has generated considerable interest among forage-livestock professionals in recent years, but questions remain about its purported benefits to cattle and forage plants. To address questions about the possible benefits of mob stocking, a 3-yr study (2014-2016) was conducted in Virginia, USA comparing mob, rotational, and continuous stocking methods in a temperate grassland common to that region. The main objective of this study was to evaluate how mob-stocking management affected selected forage variables, cattle performance, and legume/weed abundance. Herbage mass and nutritive value were measured monthly. Cow and calf weights and body condition score (BCS) were used as indicators of animal performance. Legumes (red and white clover) were over-seeded prior to the study, and their abundance along with weeds were evaluated annually thereafter. Mean herbage mass and forage nutritive values were similar across mob, rotational and continuously stocked systems despite extra-long rest periods that allowed grasses to grow tall and over-mature under mob stocking. Cow weights going into winter were lower (P < 0.05) under mob stocking (619 kg) compared with continuous stocking (688 kg) possibly because many tall grasses were trampled and not grazed. Lastly, we found mob stocking can favor establishment of erect-growing red clover (Trifolium pretense L.), but it had no effect on weed abundance. Overall, we found few compelling reasons why mob stocking should be adopted for season-long forage and livestock production over other stocking methods in this environment.
Integrated crop-livestock systems directly link crop and livestock production together to generate positive economic and environmental outcomes. Some methods used in integrated systems, like winter ...grazing on cropland, could negatively affect soil properties and crop productivity. We compared soil compaction, corn (Zea mays L.) yield, and soil nutrient pools between an integrated crop-livestock system and continuous corn system to address this issue. The study was conducted near Pana, IL, between 2002 and 2006. Soil compaction was evaluated indirectly by measuring soil penetration resistance (PR) and surface CO2 effluxes. Total soil C, N, and microbial biomass C, were measured from 2002 to 2005. Soil PR and CO2 effluxes showed inconsistent trends related to soil compaction and cattle presence. Corn yield from 2004 to 2006 was higher (P = 0.01) in the integrated system (11.6 Mg ha-1) compared with continuous corn (10.6 Mg ha-1). Total soil C concentration increased significantly from 2002 to 2005 within components of the integrated system but remained unchanged in continuous corn. Microbial biomass C was also higher in the integrated system but only in 2005. The study determined that integration of crops with livestock had generally positive effects on crop yield and soil organic matter despite the potential for livestock to compact soil during winter grazing.
Agricultural production systems in North America have become increasingly specialized. The lack of diversification has had negative economic, biological, and environmental consequences. One ...alternative approach to diversify agricultural production is to integrate cash grain cropping with ruminant livestock production. Our objective was to review research applicable to development of diversified crop-livestock systems in the U.S. Corn Belt and discuss research priorities and constraints to adoption of those systems. One form of integration becoming more common in the U.S. Corn Belt occurs through contractual arrangements between spatially separated, specialized crop and livestock production farms. Less common is the spatial and temporal integration of crops and livestock on the same land base, which can occur via rotations of grain crops with perennial pastures, short rotations of grain crops with annual or short-season pastures, and utilization of grain crop residues for livestock grazing. We feel this latter model is truer to the concept of diversification. Based on published research and preliminary results from an integrated crop-livestock system project in Illinois, we suggest that integration of crops and livestock on the same land base offers tremendous potential to diversify farm ecosystems in the U.S. Corn Belt while being economically competitive and more environmentally compatible than prevailing specialized production systems. Although studies have addressed or are applicable to components of crop-livestock systems in humid-cool environments, there remains a need for systems level research and funding opportunities for addressing the complex environment-plant-animal-economic-social interactions associated with integrated crop-livestock systems.
To ascertain the frequency of maternal and neonatal complications, as well as maternal disease severity, in pregnancies affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ...infection.
MEDLINE, Ovid, ClinicalTrials.gov, MedRxiv, and Scopus were searched from their inception until April 29, 2020. The analysis was limited to reports with at least 10 pregnant patients with SARS-CoV-2 infection that reported on maternal and neonatal outcomes.
Inclusion criteria were pregnant women with a confirmed diagnosis of SARS-CoV-2 infection. A systematic search of the selected databases was performed by implementing a strategy that included the MeSH terms, key words, and word variants for "coronavirus," "SARS-CoV-2," "COVID-19," and "pregnancy.r The primary outcomes were maternal admission to the intensive care unit (ICU), critical disease, and death. Secondary outcomes included rate of preterm birth, cesarean delivery, vertical transmission, and neonatal death. Categorical variables were expressed as percentages with number of cases and 95% CIs.
Of the 99 articles identified, 13 included 538 pregnancies complicated by SARS-CoV-2 infection, with reported outcomes on 435 (80.9%) deliveries. Maternal ICU admission occurred in 3.0% of cases (8/263, 95% CI 1.6-5.9) and maternal critical disease in 1.4% (3/209, 95% CI 0.5-4.1). No maternal deaths were reported (0/348, 95% CI 0.0-1.1). The preterm birth rate was 20.1% (57/284, 95% CI 15.8-25.1), the cesarean delivery rate was 84.7% (332/392, 95% CI 80.8-87.9), the vertical transmission rate was 0.0% (0/310, 95% CI 0.0-1.2), and the neonatal death rate was 0.3% (1/313, 95% CI 0.1-1.8).
With data from early in the pandemic, it is reassuring that there are low rates of maternal and neonatal mortality and vertical transmission with SARS-CoV-2. The preterm birth rate of 20% and the cesarean delivery rate exceeding 80% seems related to geographic practice patterns.
PROSPERO, CRD42020181497.
The Hippo pathway plays a key role in development, organ size control and tissue homeostasis, and its dysregulation contributes to cancer. The LATS tumor suppressor kinases phosphorylate and inhibit ...the YAP/TAZ transcriptional co-activators to suppress gene expression and cell growth. Through a screen of marine natural products, we identified microcolin B (MCB) as a Hippo activator that preferentially kills YAP-dependent cancer cells. Structure-activity optimization yielded more potent MCB analogs, which led to the identification of phosphatidylinositol transfer proteins α and β (PITPα/β) as the direct molecular targets. We established a critical role of PITPα/β in regulating LATS and YAP. Moreover, we showed that PITPα/β influence the Hippo pathway via plasma membrane phosphatidylinositol-4-phosphate. This study uncovers a previously unrecognized role of PITPα/β in Hippo pathway regulation and as potential cancer therapeutic targets.
Dietary sulfur amino acid restriction (SAAR) improves body composition and metabolic health across several model organisms in part through induction of the integrated stress response (ISR).
We ...investigate the hypothesis that activating transcription factor 4 (ATF4) acts as a converging point in the ISR during SAAR.
Using liver-specific or global gene ablation strategies, in both female and male mice, we address the role of ATF4 during dietary SAAR.
We show that ATF4 is dispensable in the chronic induction of the hepatokine fibroblast growth factor 21 while being essential for the sustained production of endogenous hydrogen sulfide. We also affirm that biological sex, independent of ATF4 status, is a determinant of the response to dietary SAAR.
Our results suggest that auxiliary components of the ISR, which are independent of ATF4, are critical for SAAR-mediated improvements in metabolic health in mice.
The phosphorylation of eukaryotic initiation factor 2 (p-eIF2) during dietary amino acid insufficiency reduces protein synthesis and alters gene expression via the integrated stress response (ISR).
...We explored whether a Met-restricted (MR) diet activates the ISR to reduce body fat and regulate protein balance.
Male and female mice aged 3–6 mo with either whole-body deletion of general control nonderepressible 2 (Gcn2) or liver-specific deletion of protein kinase R-like endoplasmic reticulum kinase (Perk) alongside wild-type or floxed control mice were fed an obesogenic diet sufficient in Met (0.86%) or an MR (0.12% Met) diet for ≤5 wk. Ala enrichment with deuterium was measured to calculate protein synthesis rates. The guanine nucleotide exchange factor activity of eIF2B was measured alongside p-eIF2 and hepatic mRNA expression levels at 2 d and 5 wk. Metabolic phenotyping was conducted at 4 wk, and body composition was measured throughout. Results were evaluated with the use of ANOVA (P < 0.05).
Feeding an MR diet for 2 d did not increase hepatic p-eIF2 or reduce eIF2B activity in wild-type or Gcn2−/− mice, yet many genes transcriptionally regulated by the ISR were altered in both strains in the same direction and amplitude. Feeding an MR diet for 5 wk increased p-eIF2 and reduced eIF2B activity in wild-type but not Gcn2−/− mice, yet ISR-regulated genes altered in both strains similarly. Furthermore, the MR diet reduced mixed and cytosolic but not mitochondrial protein synthesis in both the liver and skeletal muscle regardless of Gcn2 status. Despite the similarities between strains, the MR diet did not increase energy expenditure or reduce body fat in Gcn2−/− mice. Finally, feeding the MR diet to mice with Perk deleted in the liver increased hepatic p-eIF2 and altered body composition similar to floxed controls.
Hepatic activation of the ISR resulting from an MR diet does not require p-eIF2. Gcn2 status influences body fat loss but not protein balance when Met is restricted.
Producers of orchardgrass (
L.) hay in the Mid-Atlantic US have experienced a reduction in regrowth vigor and a decline in the persistence of their swards. The common management practice for the ...region is to harvest the first growth of hay by cutting at 2.5-7.5 cm height in May or June. We hypothesize that high temperature and low cutting height interact to limit the regrowth rate. To test this, orchardgrass plants were cut to either 2.5 or 7.5 cm and then placed into environmentally controlled chambers with a constant temperature of 20 or 35°C. Stubble was harvested on days 0, 1, 3, and 11 following cutting and subjected to metabolite analysis. Photosynthetic parameters were measured in the regrown leaves on days 3 and 11, and regrowth biomass was recorded on day 11. Under optimal growth temperature (20°C), vegetative regrowth upon defoliation was significantly enhanced when more stubble tissue remained. However, this advantage was not observed under heat stress. Defoliation generally decreases the abundance of carbohydrate reserves in stubble. Interestingly, high temperature stimulated the accumulation of starch and ethanol-soluble carbohydrates in plants cut to 7.5 cm. The similar trends were also observed in protein, amino acids, nitrate, and ammonium. These responses were not pronounced in plants cut to 2.5 cm, presumably due to inhibited photosynthesis and photosystem II photochemistry. Overall, we anticipated that heat-activated metabolite accumulation is part of adaptive response to the stress. However, modified allocation of carbohydrate and nitrogen reserves leads to reduced vegetative regrowth upon defoliation. These data suggest that cutting height management for orchardgrass may be more effective for its regrowth vigor and productivity in cool seasons or when cool weather follows hay harvest.
Data suggest women are more sensitive to the lipolytic action of epinephrine compared with men while maintaining similar glucoregulatory effects (Horton et al. J Appl Physiol 107: 200-210, 2009). ...This study aimed to determine the specific adrenergic receptor(s) that may mediate these sex differences. Lean women (n = 14) and men (n = 16) were studied on 4 nonconsecutive days during the following treatment infusions: saline (S: control), epinephrine E: mixed β-adrenergic (lipolytic) and α2-adrenergic (antilipolytic) stimulation, epinephrine + phentolamine (E + P: mixed β-adrenergic stimulation only), and terbutaline (T: selective β2-adrenergic stimulation). Tracer infusions of glycerol, palmitate, and glucose were administered to determine systemic lipolysis, free fatty acid (FFA) release, and glucose turnover, respectively. Following basal measurements, substrate and hormone concentrations were measured in all subjects over 90 min of treatment and tracer infusion. Women had greater increases in glycerol and FFA concentrations with all three hormone infusions compared with men (P < 0.01). Glycerol and palmitate rate of appearance (Ra) and rate of disappearance (Rd) per kilogram body weight were greater with E infusion in women compared with men (P < 0.05), whereas no sex differences were observed with other treatments. Glucose concentration and kinetics were not different between sexes with any infusion. In conclusion, these data support the hypothesis that the greater rate of lipolysis in women with infusion of E was likely due to lesser α2 antilipolytic activation. These findings may help explain why women have greater lipolysis and fat oxidation during exercise, a time when epinephrine concentration is elevated.
► Mixture yield exceeded 16tha−1 after four years with no fertilization or irrigation. ► A majority of multi-species plots exhibited overyielding. ► Moderately diverse prairie plant mixtures can ...improve forage productivity with minimal inputs.
Ten prairie plant species were grown in monoculture and mixtures of two, four, six, and all ten species for four years at a study site near Blacksburg, VA (USA) to examine relationships between species richness of perennial prairie plant mixtures and forage yield. Mixtures were highly productive, exceeding 16t (1t=1000kg)ha−1 after four years with no fertilization or irrigation. Forage yield was affected by sown species richness only in years 1 and 4 when most mixture treatments yielded more than monoculture plots. The majority of multi-species plots (71%) exhibited a positive biodiversity effect where mixtures yielded more than respective monocultures. The data also suggested a strengthening of biodiversity effects with time (more multispecies plots with relative yield totals >1 and a positive net biodiversity effect). Mixtures that were more productive than the best performing species grown in monoculture (transgressive overyielding) increased from 25% in year 1 to 54% by year 4. Plots sown with ten species produced the most consistently high and stable yields and also effectively suppressed weeds. Livestock producers in cool-season regions could improve forage productivity with minimal external inputs by adding pastures sown with moderately diverse (n=4–10 species) prairie plant mixtures.
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