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

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

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 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

Impact of mycotoxins and of a mycotoxin deactivator on alpacas grazing perennial ryegrass infected with wild endophyte (Neotyphodium spp.)

2010 ◽  
Vol 50 (9) ◽  
pp. 902 ◽  
Author(s):  
K. F. M. Reed ◽  
J. L. Vaughan ◽  
L. J. Cummins ◽  
D. D. Moore
Keyword(s):  
Perennial Ryegrass ◽  
Animal Health ◽  
Late Summer ◽  
Treated Group ◽  
The Other ◽  
Control Group ◽  
Liver Enzyme Activity ◽  
Early Autumn ◽  
Lolitrem B ◽  
The Difference

Liveweight gain, animal health and the effectiveness of a mycotoxin deactivator were studied on an old pasture that contained 61% perennial ryegrass. Sixty-seven percent of the ryegrass population was infected with endophyte (Neotyphodium spp.). The pasture was fenced into two halves and two groups of 28 alpaca male weaners were rotated between the two plots. Nine to 10 Suris and 18–19 Huacayas were allocated to each group. One group was fed a concentrate supplement (100 g/head per day) and the other was fed the same supplement to which was added the toxin deactivator, Mycofix® Plus (5 g/100 g). Mean liveweight gain on the low-quality pasture over late summer and early autumn was not significantly (P > 0.05) different between the groups. For the control group it was 41 g/day but individual rates of gain ranged from 67 to 0 g/day, depending on the severity of signs of perennial ryegrass toxicosis (r = 0.82, P < 0.001). Liveweight gain was independent of neurotoxic signs in the Mycofix® Plus treated group. Ergovaline concentration in perennial ryegrass varied from 0.43 to a peak in early autumn (March) of 1.05 mg/kg. Mean urine lysergol alkaloid concentration peaked in mid-summer (January) at 109 ng/mg creatinine (control group) and was consistently lower in the Mycofix® Plus group, although the difference approached significance (P = 0.06) only in March. Lolitrem B concentration in perennial ryegrass varied from 0.78 to 1.57 mg/kg. Neurotoxic signs in alpacas were observed throughout the study and peaked in early autumn, coinciding with peak lolitrem B concentration; at this time, 84% of alpacas exhibited neurotoxic signs. Over the 145-day study, the Mycofix® Plus treated group exhibited a lower mean rating of perennial ryegrass toxicosis signs (P < 0.05). Variation in liveweight gain and signs of toxicosis were not associated with significant differences in liver enzyme activity.

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 Progress in breeding sheep for resistance to ryegrass staggers

2007 ◽  
Vol 13 ◽  
pp. 431-431
Author(s):  
C.A. Morris ◽  
N.C. Amyes
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Metabolic Disorder ◽  
Scoring System ◽  
Neotyphodium Lolii ◽  
High Heritability ◽  
Lolitrem B ◽  
Clinical Cases

Ryegrass Staggers (RGS) is predominantly a summer/autumn metabolic disorder of ruminants, caused by ingestion of the toxin lolitrem B. The toxin is produced by an endophyte (Neotyphodium lolii) found in perennial ryegrass (Lolium perenne). In clinical cases of RGS, animals experience neuromuscular uncoordination when under stress, e.g. when mustered by sheep dogs. Experiments with a standardised RGS scoring system show that resistance/susceptibility in sheep has a moderate/high heritability (0.37 ± 0.05). An AgResearch flock was established in 1993, with two lines bred for resistance (R) or susceptibility (S) to RGS. Annually, lambs are scored for susceptibility, when both lines graze together on high endophyte pastures, and are mustered by sheep dogs. In 2005 and 2006, 2% and 6.5% of R-line lambs, respectively, showed clinical staggers, compared with 94% and 91% of S-line lambs (P

Distribution and Accumulation of the Mycotoxin Lolitrem B in Neotyphodium lolii- Infected Perennial Ryegrass

1997 ◽  
Vol 23 (5) ◽  
pp. 1435-1449 ◽  
Author(s):  
O. J.-P. Ball ◽  
G. M. Barker ◽  
R. A. Prestidge ◽  
J. M. Sprosen
Keyword(s):  
Perennial Ryegrass ◽  
Neotyphodium Lolii ◽  
Lolitrem B

scholarly journals Degradation of endophyte alkaloids in field-dried cut ryegrass herbage

2007 ◽  
Vol 13 ◽  
pp. 167-170
Author(s):  
D.E. Hume ◽  
M.J. Hickey ◽  
B.A. Tapper
Keyword(s):  
Lolium Perenne ◽  
Weather Conditions ◽  
Wild Type ◽  
Neotyphodium Lolii ◽  
Low Concentrations ◽  
Lolitrem B ◽  
Relative Decline ◽  
The Stability ◽  
Drying Regime ◽  
Over Time

The stability of endophyte alkaloids was investigated in ryegrass herbage cut and then dried in the field under a simulated hay drying regime in early and mid-summer. Ryegrass (Lolium perenne) infected with typical 'wild-type' and the 'AR37' strain of endophyte (Neotyphodium lolii) was measured for peramine, ergovaline and lolitrem B for wild-type, and epoxy-janthitrems for AR37. Despite very contrasting weather conditions, relative decline in alkaloid concentrations was similar in both early and mid-summer. Concentrations had halved within 5 to 7 days, except for lolitrem B in mid-summer which had no decline until after 4 days of drying. Ergovaline showed quite variable and erratic responses over time possibly due to the low concentrations in the cut herbage. At least in the mid-summer experiment, if herbage had been conserved at the time of normal haying making, alkaloid concentrations would have been similar to those of the herbage at the time of cutting. Keywords: endophyte, Neotyphodium lolii, Lolium perenne, peramine, lolitrem, ergovaline, janthitrems

Weather and pasture characteristics associated with outbreaks of perennial ryegrass toxicosis in southern Australia

2011 ◽  
Vol 51 (8) ◽  
pp. 738 ◽  
Author(s):  
K. F. M. Reed ◽  
Z. N. Nie ◽  
L. V. Walker ◽  
W. J. Mace ◽  
S. G. Clark
Keyword(s):  
Perennial Ryegrass ◽  
High Growth ◽  
High Growth Rate ◽  
Infection Frequency ◽  
Neotyphodium Lolii ◽  
Whole Plant ◽  
Faecal Samples ◽  
Summer Pasture ◽  
Lolitrem B ◽  
Mycelial Mass

Severe outbreaks of toxicosis caused by the natural endophyte Neotyphodium lolii in perennial ryegrass (Lolium perenne L.) have occasionally resulted in heavy loss of livestock in Victoria and Tasmania. Meteorological records were examined from locations where acute toxicosis was recorded. High rainfall (>350 mm) in spring–summer was an obvious common feature; typically, it prolonged the period of high growth rate of pasture, increasing predicted spring–summer (September–March) growth (by ~36%) and increasing the predicted digestibility of organic matter of summer pasture (1 February) by 2.7% units (up to 55.6%). In years when severe toxicosis occurred, such rainfall was accompanied by dry, warm conditions in March and April, viz. mean maximum daily temperatures on the mainland of ≥21°C (March) and ≥18°C (April). During summer–autumn 2002, pastures from 10 Victorian farms on which acute perennial ryegrass toxicosis resulted in the loss of >7000 sheep/deer, were found to be dominated by perennial ryegrass. The ryegrass endophyte-produced toxins, ergovaline and lolitrem B, were detected in 74% and 100%, respectively, of composite faecal samples collected from acutely affected animals. The populations of perennial ryegrass all tested positive for Neotyphodium lolii endophyte, with a mean infection frequency of 90.5% (s.e.m. 1.81). The mean mycelial mass in basal tillers of perennial ryegrass was estimated at 66.00 (s.e.m. 3.40) from a sample of 20 plants, each of which was assessed on a scale of 1–5. Mycelial mass accounted for 19–20% of the variation in the concentration of ergovaline and lolitrem B in perennial ryegrass. Toxin concentrations in the plants where acute toxicosis was observed exceeded the tolerance levels for sheep (ergovaline 0.8 mg/kg; lolitrem B 1.8 mg/kg) in the minor (green) fraction of the plant in all but one affected pasture for ergovaline and all but two for lolitrem B. Maximum concentrations recorded were 4.3 and 4.6 mg/kg for ergovaline and lolitrem B respectively. Ergovaline increased in an asymptotic relationship with lolitrem B, which accounted for 45% of the variation in ergovaline. The concentrations of ergovaline and lolitrem B in the whole plant (green and dead fractions combined) were not greater than those recorded from randomly sampled pastures in earlier seasons, when only occasional mild cases of toxicosis were reported. Further examination of stored grass samples collected during the 2002 outbreak recently revealed unidentified peaks on the chromatograms for both ergovaline and lolitrem B; peaks that are not seen on chromatograms for toxic perennial ryegrass from New Zealand, where the expression of perennial ryegrass toxicosis is usually milder and rarely fatal.

scholarly journals Establishing and maintaining a toxin-free pasture: a review

1999 ◽  
Vol 7 ◽  
pp. 123-132
Author(s):  
D.E. Hume
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Fungal Endophytes ◽  
Wild Type ◽  
Neotyphodium Lolii ◽  
Domestic Livestock ◽  
Buried Seed ◽  
On Farm ◽  
Sources Of Contamination

This paper reviews how new pastures may become contaminated with perennial ryegrass (Lolium perenne) infected with wild-type fungal endophytes (Neotyphodium lolii). These wild-type endophyte strains may be toxic to domestic livestock. Sources are from seed (natural reseeding, buried seed, sown seed, in dung, hay, carried on farm machinery) and survival of existing infected ryegrass plants. In particular, seed in soil and dung are reviewed. Contamination may occur both pre- and postestablishment. It is recommended that steps should be taken to minimise contamination from all sources when establishing new pastures. Although normal establishment practices for successful rapid establishment of weed-free pastures (e.g., cropping, fallow, herbicides) will minimise the risk of contamination, a number of cases highlight that extra time (e.g., 18-24 months planning rather 6- 12 months) and consideration of all sources of contamination is needed to minimise risk. Once established, further measures should be taken to prevent seed being transferred in dung or hay. This has implications when establishing pastures with endophyte-free ryegrasses, ryegrasses with selected non-toxic endophytes, a new ryegrass cultivar, or other grasses (e.g., tall fescue), whether for grazing by animals or for seed production. Keywords: endophyte, endophyte survival, faeces, Lolium perenne, natural reseeding, Neotyphodium lolii, pasture establishment, perennial ryegrass, seed burial, seed survival, tall fescue

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