Curing and storage of alfalfa hay

The difficulty in determining the stage of the curing process at any given time was largely overcome in these studies by the perfection of a weighing device which enabled the operator to determine the moisture content of the hay as it was being cured in the field. The presence of living cells in the stems and leaves of field-cured hay plants was shown. The evidence and theories on heating of hay indicate that heating is due largely to chemical oxidation processes. These processes may be helped along by the respiration of the living cells in the plant up to 40-45 °C. and by the work of microorganisms from air temperatures to 70° C. in producing unstable, unsaturated compounds. It is believed that beyond this point the heating is due entirely to chemical processes. Alfalfa hay was found to cure more rapidly in the swath than in the windrow and more rapidly in the windrow than when cocked. Hay that was one-fourth, one-half or three-fourths cured in the swath prior to windrowing cured more rapidly than the hay windrowed at once, and the longer the hay was allowed to remain in the swath, the less time was required for curing. Cocking hay, either at once or after partial swath Or windrow-curing, delayed the curing process. Green hay in large cocks heated and lost its color. Good quality hay was made by cocking after partial swath or windrow-curing. Turning average sized windrows with the rake in good curing weather was found to be slightly detrimental as no appreciable time was gained and the quality of the hay was slightly lowered. Turning large windrows or windrows wet by rain caused them to cure more rapidly and gave a better quality of hay. Tedding hay was not found to be advantageous in any way in these experiments and was detrimental to the quality of the hay. The tedder may be valuable in curing extremely heavy swaths of hay. Complete swath-curing resulted in the greatest loss of leaves; three-fourth and one-half swath-curing were next in amount of leaves lost. Windrowing at once and one-fourth swath-curing followed by windrowing resulted in the least loss of leaves. The leaf-loss in swath-curing hay was increased by the use of the tedder. The turning of the windrow with the rake caused an additional leaf-loss in windrow-cured hay. DurIng these experiments hay was placed in the mow with as low as 20 percent and as high as 58.7 percent of moisture. The degree of heating was not found to be directly proportional to the moisture content of the hay. Hay with below 30 percent of moisture ordinarily may be considered safe from heating to a destructive or dangerous degree. Hay with less than 27 percent of moisture may be expected to retain its green color. The hay generally heats immediately on being mowed, then cools; this is followed by a second heating period in which the highest temperature is usually reached in 8 to 10 days after mowing, after which the hay cools gradually. The amount of carbon dioxide present in the mow, is a fair indication of the degree of heating of the hay . . The accumulation of carbon dioxide in the presence of moist, hot material results in a transformation of the chlorophyll, accompanied by a change in color from green to brown. The green color of hay was usually destroyed when the heating exceeded 50°C. Clean, brown hay is formed at temperatures above 55°C. and below 70 °C. In general, moldy, grayish-brown hay results when hay heats to between 40 and 50°C. during the storage period. Clean, brown hay is formed by heating quickly to 55° C., while if the heating is prolonged at 50° C. or less and later heats to above 55°C., the hay is dusty. The value of salting hay in the mow was tested eight times, with a distinctly beneficial effect once, slightly beneficial once and apparently no benefit in six trials. When hay baled from the field with 23 percent of moisture was carefully stored, there was no detrimental heating

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

Introduction: The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures. Methods: In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025. Findings: Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2–6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5–5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4–10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32–4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23–11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation. Interpretation: After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Curing and storage of alfalfa hay

The difficulty in determining the stage of the curing process at any given time was largely overcome in these studies by the perfection of a weighing device which enabled the operator to determine the moisture content of the hay as it was being cured in the field. The presence of living cells in the stems and leaves of field-cured hay plants was shown. The evidence and theories on heating of hay indicate that heating is due largely to chemical oxidation processes. These processes may be helped along by the respiration of the living cells in the plant up to 40-45 °C. and by the work of microorganisms from air temperatures to 70° C. in producing unstable, unsaturated compounds. It is believed that beyond this point the heating is due entirely to chemical processes. Alfalfa hay was found to cure more rapidly in the swath than in the windrow and more rapidly in the windrow than when cocked. Hay that was one-fourth, one-half or three-fourths cured in the swath prior to windrowing cured more rapidly than the hay windrowed at once, and the longer the hay was allowed to remain in the swath, the less time was required for curing. Cocking hay, either at once or after partial swath Or windrow-curing, delayed the curing process. Green hay in large cocks heated and lost its color. Good quality hay was made by cocking after partial swath or windrow-curing. Turning average sized windrows with the rake in good curing weather was found to be slightly detrimental as no appreciable time was gained and the quality of the hay was slightly lowered. Turning large windrows or windrows wet by rain caused them to cure more rapidly and gave a better quality of hay. Tedding hay was not found to be advantageous in any way in these experiments and was detrimental to the quality of the hay. The tedder may be valuable in curing extremely heavy swaths of hay. Complete swath-curing resulted in the greatest loss of leaves; three-fourth and one-half swath-curing were next in amount of leaves lost. Windrowing at once and one-fourth swath-curing followed by windrowing resulted in the least loss of leaves. The leaf-loss in swath-curing hay was increased by the use of the tedder. The turning of the windrow with the rake caused an additional leaf-loss in windrow-cured hay. DurIng these experiments hay was placed in the mow with as low as 20 percent and as high as 58.7 percent of moisture. The degree of heating was not found to be directly proportional to the moisture content of the hay. Hay with below 30 percent of moisture ordinarily may be considered safe from heating to a destructive or dangerous degree. Hay with less than 27 percent of moisture may be expected to retain its green color. The hay generally heats immediately on being mowed, then cools; this is followed by a second heating period in which the highest temperature is usually reached in 8 to 10 days after mowing, after which the hay cools gradually. The amount of carbon dioxide present in the mow, is a fair indication of the degree of heating of the hay . . The accumulation of carbon dioxide in the presence of moist, hot material results in a transformation of the chlorophyll, accompanied by a change in color from green to brown. The green color of hay was usually destroyed when the heating exceeded 50°C. Clean, brown hay is formed at temperatures above 55°C. and below 70 °C. In general, moldy, grayish-brown hay results when hay heats to between 40 and 50°C. during the storage period. Clean, brown hay is formed by heating quickly to 55° C., while if the heating is prolonged at 50° C. or less and later heats to above 55°C., the hay is "dusty." The value of salting hay in the mow was tested eight times, with a distinctly beneficial effect once, slightly beneficial once and apparently no benefit in six trials. When hay baled from the field with 23 percent of moisture was carefully stored, there was no detrimental heating.</p

Plant parasitic nematodes: the effect of lolines.

Grass endophytes live their entire life cycle within the aerial portion of the grass host, with which they form a defensive mutualism. The endophyte which resides intercellularly within the grass, synthesizes an array of alkaloids that collectively deter mammalian, insect and nematode herbivory. Reciprocally the endophyte profits directly from the host’s provision of nutrients, water, isolation from competition and guarantee of vertical transmission to the next host generation. The discovery by Bacon et al., (1977) of a link between livestock toxicity and endophyte presence in pasture initially resulted in the selection for nil endophyte grasses. However it was soon discovered that production and persistence of nil endophyte grass stands were decidedly inferior to endophyte-infected stands. Further research revealed that there was much variation in the alkaloids and respective functions, produced within and between species of Neotyphodium endophytes. Some endophytes were shown to confer resistance to an array of insect pests without extending any ill effect to livestock. Since then these endophytes, referred to hereafter as ‘novel’ endophytes have been selected and bred into grass with high agronomic value However concerns have been raised regarding persistence of novel endophyte infected tall fescue stands under plant parasitic nematode pressure. These nematodes through feeding on and burrowing through young root tissue affect the water uptake capability of the grass roots. This compromises plant persistence under drought conditions particularly on free draining sandy soils. This problem warrants investigation of all grass-endophyte associations and alkaloid interactions in a bid to identify such an association that would confer resistance to this pest. Three glasshouse pot trials were conducted at Lincoln University, Canterbury, NZ. The objective of the trials were to (1) investigate the relationship between the root concentrations of Neotyphodium produced alkaloid (loline) and nematode parasitism; (2) To investigate the effect of nematode parasitism on plant loline synthesis as a defensive response mechanism. (3) To investigate whether lolines leached from endophyte-infected, dead grass material is taken up by neighbouring plants. Due the unfortunate necessity to pool replications, results attained from this trial were merely indicative. The results however did suggest that there is an inversely proportional relationship between nematode presence in roots and total root loline concentrations. Additionally the results suggested that root loline concentrations increased with trimming and nematode herbivory. There no evidence to suggest that loline leached from endophyte-infected dead grass material were taken up by other members of the plant community. The suggestive evidence presented in the results of the first two trials holds significant implications for New Zealand and International pastoral agriculture if shown by further research to be accurate. Loline producing endophytes such as Neotyphodium uncinatum can now be bred or introduced into prominent pastoral grasses Festuca arundinacea Shreb. and Lolium perenne L. This would extend the nematoxic properties of loline, which confers no ill effect to grazing livestock, to these important pasture constituents