Production and physiological effects of perennial ryegrass alkaloids under thermoneutral conditions in Merinos

2016 ◽  
Vol 56 (10) ◽  
pp. 1629 ◽  
Author(s):  
M. L. E. Henry ◽  
S. Kemp ◽  
I. J. Clarke ◽  
F. R. Dunshea ◽  
B. J. Leury
Keyword(s):  
Perennial Ryegrass ◽  
High Dose ◽  
Plasma Prolactin ◽  
Physiological Effects ◽  
Wild Type ◽  
Short Period ◽  
Lolitrem B ◽  
Whole Seed ◽  
C 50 ◽  
Linear Manner

A confined feeding study was conducted to compare the production and physiological effects of feeding three doses of wild-type perennial ryegrass alkaloids via whole seed to Merino sheep housed under thermoneutral conditions (21°C, 50% relative humidity). Eighteen Merino ewe weaners (16 months; initial bodyweight 47 ± 1.94 kg) were offered Nil, Low (50 µg/kg liveweight ergovaline, 22 µg/kg liveweight lolitrem B) or High (100 µg/kg liveweight ergovaline, 44 µg/kg liveweight lolitrem B) doses of alkaloids for 21 days. Dry matter intake tended (P = 0.072) to decrease in a linear manner with increasing dietary alkaloid concentration. Rectal temperature and respiration rate increased (P = 0.002 for both) in a linear manner with increasing dietary alkaloid concentration. Oxygen consumption increased linearly (P = 0.064) and quadratically (P = 0.015) with increasing alkaloid concentration, being highest in the Low dose and intermediate in the High dose group. Plasma prolactin decreased linearly (P = 0.002) with increasing dietary alkaloids. These data clearly show that animal production and efficiency are compromised when sheep consume perennial ryegrass alkaloids, even over a short period of time. This study indicates that a pyrogenic response can occur when alkaloids are consumed, even under thermoneutral conditions.

The impact of endophyte on the health and productivity of sheep grazing ryegrass-based pastures

1999 ◽  
Vol 7 ◽  
pp. 11-17
Author(s):  
L.R. Fletcher ◽  
B.L. Sutherland ◽  
C.G. Fletcher
Keyword(s):  
Perennial Ryegrass ◽  
Growth Rates ◽  
Plasma Prolactin ◽  
Sheep Grazing ◽  
Wild Type ◽  
Lower Plasma ◽  
Lower Growth ◽  
Respiration Rates ◽  
Neotyphodium Lolii ◽  
The Impact

The health and production of sheep grazing perennial ryegrass with and without wild-type endophyte (Neotyphodium lolii) has been studied in several trials over a number of years. Lambs/ hoggets grazing predominantly perennial ryegrass swards with endophyte developed moderate to severe ryegrass staggers in summer and autumn, while those grazing endophyte-free ryegrass did not. Lambs/hoggets grazing ryegrass with endophyte also had more dags, lower growth rates, lower plasma prolactin levels, higher body temperatures and respiration rates under warm humid conditions. Most of these adverse responses were more severe in summer and autumn when endophyte toxin concentrations were highest. Many of these symptoms are similar to those described for the "autumn ill thrift" syndrome in New Zealand. Keywords: dags, endophyte, flystrike, growth rates, hyperthermia, Neotyphodium, perennial ryegrass, prolactin, ryegrass staggers, sheep

scholarly journals Evaluation of several lolitrem-free endophyte/perennial ryegrass combinations

1991 ◽  
pp. 215-219 ◽  
Author(s):  
L.R. Fletcher ◽  
A.J. Popay ◽  
B.A. Tapper
Keyword(s):  
Weight Loss ◽  
Perennial Ryegrass ◽  
Fungal Endophyte ◽  
Feeding Deterrent ◽  
Animal Performance ◽  
Wild Type ◽  
Affected Animal ◽  
Lolitrem B

The fungal endophyte Acremonium lolii, in association with its ryegrass host, produces both peramine, a feeding deterrent to Argentine stem weevil,andlolitrem B,a neurotoxin causing ryegrass staggers. Endophyte strains vary in the ratio of production of these alkaloids in the ryegrass. In field evaluations of several endophyte/ryegrass - combinations, 'Endosafe', a zero lolitrem B, high peramine strain protected its host against Argentine stem weevil attack and did not cause ryegrass staggers in lambs grazing three of four ryegrass cultivars. Lambs on the endophyte-free and Endosafe combinations had the highest liveweight gains and while endophyte-free ryegrass did not cause ryegrass staggers it suffered significant stem weevil damage. Ryegrasses with their 'wild-type' endophyte and a high lolitrem B strain 'Waiau', had only minor stem weevil damage but caused severe ryegrass staggers and weight loss in lambs. Ryegrass with the no lolitrem B, low peramine strain, 'IOOA', suffered some stem weevil damage and although not causing ryegrass staggers, did cause weight loss in lambs. Ryegrass/endophyte metabolites in addition to lolitrem B may have affected animal performance on endophyte-infected ryegrass. Keywords endophytc, Endosafe, perennial ryegrass,ryegrass staggers, Argentine stem weevil, liveweight gains, peramine, lolitrem B

scholarly journals Field performance of perennial ryegrass (Lolium oerenne) infected with toxin-free fungal endophytes (Neotyphodium spp.)

1999 ◽  
Vol 7 ◽  
pp. 113-122
Author(s):  
A.J. Popay ◽  
D.E. Hume ◽  
J.G. Baltus ◽  
G.C.M. Latch ◽  
B.A. Tapper ◽  
...  
Keyword(s):  
Insect Resistance ◽  
Perennial Ryegrass ◽  
Fungal Endophytes ◽  
Field Performance ◽  
Insect Damage ◽  
Wild Type ◽  
Pasture Production ◽  
Adult Feeding ◽  
Lolitrem B ◽  
Beetle Damage

A national series of six small plot trials were sown in 1996 and four in 1997 to evaluate the performance of six novel fungal endophytes in Grasslands Nui perennial ryegrass. These endophytes do not produce the mammalian toxins, ergovaline and lolitrem B, but produce peramine, a feeding deterrent to the major ryegrass pest, Argentine stem weevil (ASW). Trials included the naturally occurring endophyte (wild-type) which produces both toxins, and an endophyte-free (nil) treatment. Pasture production was measured regularly and samples were taken at least once each summer-autumn from all trials for assessment of ASW damage. Black beetle larval damage was recorded on three trials. The toxin-free endophytes, AR1, AR12, AR22 and the wild-type were equally effective at reducing ASW adult feeding and larval damage significantly below that which occurred in nil treatments. Ryegrass infected with AR1, AR12, AR22 and the wild-type endophyte was damaged less by black beetle larvae than ryegrass without endophyte. The effect of AR24 on insect damage was variable and two other toxin-free endophytes, AR17 and AR506, which had low infection rates, seldom reduced either ASW or black beetle damage. Yield differences between treatments were found on two of 21 sampling occasions between October and December and 12 of 30 sampling occasions between January and April. During summer-autumn, wild-type, AR1, AR12 and AR22 gave higher ryegrass yields than the nil, AR17 and AR506 treatments. In the second year of the 1996-sown trials, productivity of ryegrass with AR1 in the summer-autumn tended to be lower than that of the wild-type with significant differences occasionally occurring. Yield differences were correlated with either ASW or black beetle damage in North Island trials and with percent endophyte infection at all sites. Differences in yield at Lincoln, Canterbury, were attributed to pasture mealy bug. Three conclusions were drawn from these results: 1. Endophytes are very important for maximising ryegrass yield during summer and early autumn. 2. The effect of endophytes on yield is at least partly due to the insect resistance they impart. 3. The field performance of three toxin-free endophytes, AR1, AR12 and AR22, equalled that of the wild-type in terms of increased insect resistance but did not always match it in plant growth. Keywords: AR1, Argentine stem weevil, black beetle, endophyte strain, ergovaline, insect damage, lolitrem B, Neotyphodium lolii, ryegrass yield

Fluctuations in the concentration of ergovaline and lolitrem B produced by the wild-type endophyte (Neotyphodium lolii) in perennial ryegrass (Lolium perenne) pasture

2011 ◽  
Vol 51 (12) ◽  
pp. 1098 ◽  
Author(s):  
K. F. M. Reed ◽  
Z. N. Nie ◽  
L. V. Walker ◽  
G. Kearney
Keyword(s):  
Seed Development ◽  
Perennial Ryegrass ◽  
Animal Health ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Wild Type ◽  
Neotyphodium Lolii ◽  
Eastern Australia ◽  
Lolitrem B

Mammalian toxins produced by the wild-type endophyte, Neotyphodium lolii, in perennial ryegrass (PRG) pasture cause production losses and animal health and welfare problems in livestock. Managing this risk is limited by the lack of information on fluctuations in the concentration of toxin in Australian pasture. We investigated how the toxin concentrations may be related to recent observations of weather. Swards sown from common seedlots of two cultivars of wild endophyte-infected PRG, grazed short by sheep, were sampled at 2–4 weekly intervals from spring to autumn at two sites in Victoria. The highest concentration of ergovaline and lolitrem B was observed at Hamilton, the site with the longer-growing season. The concentration of ergovaline peaked in early summer, coinciding with seed development, and declined through summer, before increasing with the commencement of autumn growth. The concentration of lolitrem B remained low in summer, then rose in autumn. Variation between the two cultivars in the concentration of toxins was small and rarely significant. The concentration of ergovaline declined as the mean daily maximum temperature over the preceding 1–5 days increased. Similarly, for lolitrem B, the concentration declined over the temperature range 12−20°C, from 1.3 to 0.3 mg/kg. At Hamilton, where solar radiation and soil temperature were recorded, both were superior to maximum temperature for predicting lolitrem B. Serial sampling of PRG from old naturalised pasture on seven farms across south-eastern Australia found two seasonal peaks for both alkaloids in most pastures. The concentration of ergovaline reached or exceeded tolerance levels for livestock in 23 of 43 samples, compared with 5 of 43 for lolitrem B. Ergovaline concentrations initially peaked (at 1.0–1.6 mg/kg) when mature reproductive material was present (coinciding with peduncle elongation and seed development). In pastures with low grazing pressure, i.e. where growth was allowed to continue through summer, ergovaline concentration was relatively low (<0.7 mg/kg) but in a hard-grazed pasture (sward height 3 cm), the ergovaline concentration was greater (up to 1.1 mg/kg). Concentration of lolitrem B also peaked in December, except on pasture where growth continued through summer. High concentrations of lolitrem B associated with neurotoxic signs in sheep (viz. 2.4–3.9 mg/kg) were observed only in mid-summer and autumn, and only if conditions favoured growth or where close grazing by sheep left the crown as the dominant source of herbage.

scholarly journals "Non-toxic" endophytes in ryegrass and their effect on livestock health and production

1999 ◽  
Vol 7 ◽  
pp. 133-139
Author(s):  
L.R. Fletcher
Keyword(s):  
Perennial Ryegrass ◽  
The Other ◽  
Serum Prolactin ◽  
Sheep Grazing ◽  
Wild Type ◽  
Respiration Rates ◽  
Neotyphodium Lolii ◽  
Lolitrem B ◽  
Livestock Health ◽  
Gross Margins

Ryegrass/endophyte associations have been developed which produce peramine, but not the endophyte toxins ergovaline or lolitrem B. Sheep grazing these ryegrasses in small paddocks and in a systems trial over three years gained weight as rapidly as those grazing endophyte-free ryegrass, and showed none of the adverse responses associated with grazing ryegrass naturally infected with wild-type endophyte (Neotyphodium lolii). Growth rates, rectal temperatures, respiration rates, serum prolactin concentrations, ryegrass staggers scores and scores for dag burdens were equivalent for the selected endophyte and nil endophyte treatments, whereas sheep grazing the wild-type endophyte treatment were adversely affected for all parameters. This was reflected in calculated gross margins for the systems trial of only $605 per hectare for the wild-type endophyte treatment compared with over $700 per hectare for each of the other treatments. To date there have been no conclusive studies of non-toxic endophyte with cattle. Keywords: AR1, dags, endophyte, ergovaline, liveweight gain, lolitrem B, Lolium perenne, Neotyphodium, peramine, perennial ryegrass, prolactin, sheep

scholarly journals Prominent Indomethacin-Induced Enteropathy in Fcgriib Defi-cient lupus Mice: An Impact of Macrophage Responses and Immune Deposition in Gut

2021 ◽  
Vol 22 (3) ◽  
pp. 1377
Author(s):  
Thansita Bhunyakarnjanarat ◽  
Kanyarat Udompornpitak ◽  
Wilasinee Saisorn ◽  
Bhumdhanin Chantraprapawat ◽  
Peerapat Visitchanakun ◽  
...  
Keyword(s):  
Cytokine Production ◽  
High Dose ◽  
Flux Analysis ◽  
Wild Type ◽  
Fc Gamma Receptor ◽  
Serum Cytokines ◽  
Extracellular Flux ◽  
Gamma Receptor ◽  
Gut Leakage ◽  
Gastrointestinal Permeability

A high dose of NSAIDs, a common analgesic, might induce lupus activity through several NSAIDs adverse effects including gastrointestinal permeability defect (gut leakage) and endotoxemia. Indomethacin (25 mg/day) was orally administered for 7 days in 24-wk-old Fc gamma receptor IIb deficient (FcgRIIb-/-) mice, an asymptomatic lupus model (increased anti-dsDNA without lupus nephritis), and age-matched wild-type (WT) mice. Severity of indomethacin-induced enteropathy in FcgRIIb-/- mice was higher than WT mice as demonstrated by survival analysis, intestinal injury (histology, immune-deposition, and intestinal cytokines), gut leakage (FITC-dextran assay and endotoxemia), serum cytokines, and lupus characteristics (anti-dsDNA, renal injury, and proteinuria). Prominent responses of FcgRIIb-/- macrophages toward lipopolysaccharide (LPS) compared to WT cells due to the expression of only activating-FcgRs without inhibitory-FcgRIIb were demonstrated. Extracellular flux analysis indicated the greater mitochondria activity (increased respiratory capacity and respiratory reserve) in FcgRIIb-/- macrophages with a concordant decrease in glycolysis activity when compared to WT cells. In conclusion, gut leakage-induced endotoxemia is more severe in indomethacin-administered FcgRIIb-/- mice than WT, possibly due to the enhanced indomethacin toxicity from lupus-induced intestinal immune-deposition. Due to a lack of inhibitory-FcgRIIb expression, mitochondrial function, and cytokine production of FcgRIIb-/- macrophages were more prominent than WT cells. Hence, lupus disease-activation from NSAIDs-enteropathy-induced gut leakage is possible.

Exacerbated febrile responses to LPS, but not turpentine, in TNF double receptor-knockout mice

1997 ◽  
Vol 272 (2) ◽  
pp. R563-R569 ◽  
Author(s):  
L. R. Leon ◽  
W. Kozak ◽  
J. Peschon ◽  
M. J. Kluger
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Motor Activity ◽  
Knockout Mice ◽  
Low Dose ◽  
Late Phase ◽  
High Dose ◽  
Wild Type ◽  
Inflammatory Stimuli ◽  
Necrosis Factor

We examined the effects of injections of systemic [lipopolysaccharide (LPS), 2.5 mg/kg or 50 pg/kg ip] or local (turpentine, 100 microl sc) inflammatory stimuli on fever, motor activity, body weight, and food intake in tumor necrosis factor (TNF) double receptor (TNFR)-knockout mice. A high dose of LPS resulted in exacerbated fevers in TNFR-knockout mice compared with wild-type mice for the early phase of fever (3-15 h); the late phase of fever (16-24 h) and fevers to a low dose of LPS were similar in both groups. Motor activity, body weight, and food intake were similarly reduced in both groups of mice after LPS administration. In response to turpentine, TNFR-knockout and wild-type mice developed virtually identical responses to all variables monitored. These results suggest that 1) TNF modulates fevers to LPS dose dependently, 2) TNF does not modulate fevers to a subcutaneous injection of turpentine, and 3) knockout mice may develop cytokine redundancy in the regulation of the acute phase response to intraperitoneally injected LPS or subcutaneously injected turpentine.

scholarly journals High-dose vitamin C infusion for the treatment of critically ill COVID-19

2020 ◽  
Author(s):  
Jing Zhang ◽  
Xin Rao ◽  
Yiming Li ◽  
Yuan Zhu ◽  
Fang Liu ◽  
...  
Keyword(s):  
Placebo Group ◽  
Vitamin C ◽  
Critically Ill ◽  
Day Treatment ◽  
Invasive Mechanical Ventilation ◽  
Controlled Clinical Trial ◽  
High Dose ◽  
C 50 ◽  
Intravenous Vitamin ◽  
High Dose Vitamin

Abstract BackgroundNo specific medication has been proven effective for the treatment of patients with severe coronavirus disease 2019 (COVID-19). Here, we tested whether high-dose vitamin C infusion was effective for severe COVID-19.MethodsThis randomized, controlled clinical trial was performed at 3 hospitals in Hubei, China. Patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the ICU were randomly assigned in as 1:1 ratio to either the high-dose intravenous vitamin C (HDIVC) or the placebo. HDIVC group received 12 g of vitamin C/50 ml every 12 hours for 7 days at a rate of 12 ml/hour, and the placebo group received bacteriostatic water for injection in the same way. The primary outcome was invasive mechanical ventilation-free days in 28 days(IMVFD28). Secondary outcomes were 28-day mortality, organ failure, and inflammation progression.ResultsFifty-four critical COVID-19 patients were ultimately recruited. There was no difference in IMVFD28 between two groups. During the 7-day treatment period, patients in the HDIVC group had a steady rise in the PaO2/FiO2 (day 7: 229 vs. 151 mmHg, 95% CI 33 to 122, P = 0.01). Patients with SOFA scores ≥ 3 in the HDIVC group exhibited a significant reduction in 28-day mortality (P = 0.05) in univariate survival analysis. IL-6 in the VC group was lower than that in the placebo group (19.42 vs. 158.00; 95% CI -301.72 to -29.79; P = 0.04) on day 7.ConclusionThe addition of HDIVC may provide a protective clinical effect without any adverse events in critically ill patients with COVID-19.Clinicaltrial.gov identifer: NCT04264533

scholarly journals Determination of the toxic threshold of lolitrem B in cattle eating endophye-infected perennial ryegrass

2007 ◽  
Vol 13 ◽  
pp. 399-402
Author(s):  
L. Blythe ◽  
C. Estill ◽  
J. Males ◽  
A.M. Craig
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Clinical Signs ◽  
Positive Control ◽  
Control Group ◽  
Crossbred Cattle ◽  
Testing Laboratory ◽  
Neotyphodium Lolii ◽  
Lolitrem B

Perennial ryegrass (Lolium perenne) straw is used as a feed for livestock and horses. Some straw is infected with the endophyte, Neotyphodium lolii, which produces lolitrem tremorgens. Ingesting of the toxin produces clinical "ryegrass staggers." A 28 day feeding trail was conducted using 61 Black Angus, pure and crossbred cattle. The cattle were fed one of three levels of lolitrem B in chopped perennial ryegrass straw ranging from 0 ppb up to 3058 ppb. Four Japanese Wagyu crossbred cattle were fed chopped ryegrass straw containing 1400 ppb lolitrem B. The cattle were evaluated and scored twice a day for clinical signs of gait difficulties. Cattle consuming 1400 ppb lolitrem B did not show any overt clinical signs. After 14 days, 7 out of 15 cattle in the 1954 ppb lolitrem B group showed clinical signs of ataxia, stiffness, and tremors as seen in ryegrass staggers. All of the cattle in the positive control group of up to 3058 ppb lolitrem B with a 4 week mean of 2574 ppb developed clinical signs of staggers. None of the Wagyu cattle at 1400 ppb lolitrem B developed clinical signs. A dose response curve was developed based on the results of this study coupled with a prior study for use in the testing laboratory. Keywords: lolitrem B, perennial ryegrass, Lolium perenne, endophyte fungus, Neotyphodium lolii, cattle, threshold levels

Physiological effects of a short period of adaptation to the farrowing environment in gilts

1998 ◽  
Vol 1998 ◽  
pp. 41-41
Author(s):  
A.B. Lawrence ◽  
K.A. McLean ◽  
C.L. Gilbert ◽  
S. Calvert ◽  
J. Chirnside ◽  
...  
Keyword(s):  
Physiological Effects ◽  
Minimal Period ◽  
Short Period ◽  
Oxytocin Release

Moving gilts from a strawed pen to a crate during farrowing profoundly inhibits oxytocin, probably as a result of a stress-induced opioid-inhibition of hypothalamic oxytocin release (Lawrence et al., 1992). Other work suggests that confinement of gilts in crates for 5 days prior to farrowing protects the gilt against stressinduced inhibition of oxytocin. As producers introduce gilts and sows into farrowing crates at variable times prior to farrowing it is important to identify the minimal period of exposure to crates required to confer adaptation. This work tested whether only a short period of adaptation (1 day) to farrowing crates prior to expected farrowing date (EFD) would be sufficient to prevent stress-induced inhibition of oxytocin.

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