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

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

scholarly journals Performance of lambs and the incidence of staggers and heat stress on two perennial ryegrass cultivars over three summers in the Manawatu

1999 ◽  
Vol 7 ◽  
pp. 143-150
Author(s):  
S.J. Bluett ◽  
J. Hodgson ◽  
P.D. Kemp ◽  
T.N. Barry
Keyword(s):  
Organic Matter ◽  
Heat Stress ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Nutritive Value ◽  
Stress Symptoms ◽  
Neotyphodium Lolii ◽  
Lolitrem B ◽  
Organic Matter Digestibility ◽  
Lamb Growth

Three lamb growth experiments were carried out at Massey University, Palmerston North, from 1995 to 1998 to evaluate the nutritive value and endophyte (Neotyphodium lolii) status of a new perennial ryegrass (Lolium perenne L.) cultivar (Aries HD). Aries HD was specifically selected for improved organic matter digestibility over summer and early autumn. Lamb liveweight gain on 'Aries HD' compared to a control cultivar 'Yatsyn 1' perennial ryegrass was higher in the summer of 1995/96 (104 vs 84 ± 4.6 g/day, P=0.1028), similar in two consecutive summers, 1996/97 (116 vs 111 ± 5.1 g/day, P=0.6542), and 1997/98 (71 vs 73 g/day ± 10.6 g/day, P=0.7350). The nutritive value (invitro organic matter digestibility, neutral detergent fibre and nitrogen content) of Aries HD and Yatsyn 1 pastures was similar. Lambs grazing Yatsyn 1 were more severely affected by ryegrass staggers than lambs grazing Aries HD, although the concentrations of lolitrem B in grazed herbage were similar. The concentration of ergovaline in Aries HD in association with endophyte was about half that in Yatsyn 1 in association with endophyte. Ergovaline may have acted synergistically to increase the toxicity of lolitrem B and the severity of staggers in lambs grazing Yatsyn 1 pastures. There was some indication that heat stress symptoms were more severe in lambs forced to graze lower into the sward. The effect of management and alkaloid concentration is likely to have a larger impact on lamb performance than small differences in nutritive value between cultivars of highendophyte perennial ryegrass. Keywords: alkaloids, animal performance, Aries HD, endophyte, heat stress, Lolium perenne, Neotyphodium lolii, perennial ryegrass, ryegrass staggers, Yatsyn 1

Incidence of ryegrass endophyte (Neotyphodium lolii) and diversity of associated alkaloid concentrations among naturalised populations of perennial ryegrass (Lolium perenne L.)

2000 ◽  
Vol 51 (5) ◽  
pp. 569 ◽  
Author(s):  
K. F. M. Reed ◽  
A. Leonforte ◽  
P. J. Cunningham ◽  
J. R. Walsh ◽  
D. I. Allen ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Critical Level ◽  
Clinical Symptoms ◽  
Lolium Perenne L ◽  
Grass Endophyte ◽  
Neotyphodium Lolii ◽  
The Mean ◽  
Lolitrem B ◽  
Mutualistic Association

The mutualistic association between perennial ryegrass (Lolium perenne L.) and the ryegrass endophyte Neotyphodium lolii (Latch, Christensen and Samuels) Glenn, Bacon and Hanlin, previously assigned to the genus Acremonium, is known to have a major impact on pasture and animal production. The perennial ryegrass ecotypes Victorian and Kangaroo Valley are the most widely sown varieties of grass in Australian pasture. The incidence of ryegrass endophyte (N. lolii) in these ecotypes, and the production of alkaloids associated with theryegrass endophyte, are largely unexplored. Fifty-six populations of Victorian and 45 of Kangaroo Valley were sampled from old pasture within the recognised zones of naturalisation of both ecotypes. All of the 101 populations examined were infected with ryegrass endophyte. The mean ryegrass endophyte (N. lolii) frequency for plants within the populations of the Victorian and Kangaroo Valley ecotypes was 88% and 93%, respectively. Alkaloid concentrations were determined from infected plants for 39 Kangaroo Valley populations and, in a separate study, for 24 Victorian populations. Ergovaline concentration was above the critical level of 0.4 mg/kg (above which clinical symptoms are observed) for 10% of the Kangaroo Valley populations and 17% of the Victorian populations. For lolitrem B, all Victorian populations were below the critical level of 1.8 mg/kg, but 28% of the Kangaroo Valley populations had mean concentrations above the critical level, 1.8 mg/kg. Concentrations for individual plants were <5 mg/kg for ergovaline, <6 mg/kg for lolitrem B, and <48 mg/kg for peramine. Within each ecotype examined, significant variation (P < 0.05) in the mean concentrations of ergovaline, lolitrem B, and peramine was found between the populations of naturalised perennial ryegrass. Mean concentrations for some of the various naturalised populations were higher than that observed in some of the control cultivars. Low ergovaline and lolitrem B concentrations observed for individual genotypes indicate scope for selecting grass endophyte combinations characterised by optimum production of alkaloids.

scholarly journals Survival of endophyte-infected ryegrass seed buried in soil

1999 ◽  
Vol 7 ◽  
pp. 151-156
Author(s):  
D.E. Hume ◽  
M.P. Rolston ◽  
D.B. Baird ◽  
W.J. Archie ◽  
M.R. Marsh
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Seed Viability ◽  
Seed Storage ◽  
Fungal Endophyte ◽  
Grass Species ◽  
Soil Conditions ◽  
Neotyphodium Lolii ◽  
Viable Seeds ◽  
One Year

Emergence of volunteer perennial ryegrass (Lolium perenne L.) from seed buried in soil may contribute to the ingress of ryegrass in newly sown pastures. To investigate this, ryegrass seed infected with fungal endophyte (Neotyphodium lolii) was buried in nylon bags under pasture at two depths and at two sites (Palmerston North, Lincoln) in early/mid-autumn 1998. Seed bags were removed from the soil at intervals over the course of one year to determine seed viability and presence of endophyte in seedlings. Viability of seed declined rapidly to be 10% 3 months after burial. Further decline in viability was less, so that 12 months after burial 4% of seeds were still viable. Endophyte viability also declined, from 58% infection of seedlings at the time of burial to 21% at 12 months. This was at a slower rate than the decline in seed viability and from what might have been predicted from seed storage experiments. Viability of seed buried at 10 cm was greater than that buried at 3 cm (e.g., means, 10% and 1% after 6 months, respectively). This has implications for cultivation practices before pasture establishment. Seed buried at Lincoln maintained higher viability than seed buried at Palmerston North (e.g., means, 6% and 4% after 6 months, respectively), which was associated with drier soil conditions at Lincoln. Survival of buried seed may therefore be of greater importance in summer-dry east coast regions, compared with moist west coast environments or in wet years. The significance of buried ryegrass seed will depend on the numbers involved, but after 12 months there were still viable seeds left in the soil and some of these were infected with endophyte. This is important for pastures sown with ryegrass that is free of endophyte or infected with a selected endophyte, and for slower establishing grass species such as tall fescue. Keywords: endophyte, endophyte survival, Lolium perenne, Neotyphodium lolii, perennial ryegrass, seed burial, seed survival

scholarly journals Toxic Indole Diterpenes from Endophyte-Infected Perennial Ryegrass Lolium perenne L.: Isolation and Stability

Toxins ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 16 ◽  
Author(s):  
Priyanka Reddy ◽  
Myrna A. Deseo ◽  
Vilnis Ezernieks ◽  
Kathryn Guthridge ◽  
German Spangenberg ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Rapid Development ◽  
Toxicity Testing ◽  
Flash Chromatography ◽  
Preparative Hplc ◽  
Purification Method ◽  
Isolation And Purification ◽  
Lolium Perenne L ◽  
Lolitrem B

The most potent of the indole diterpenes, lolitrem B, is found in perennial ryegrass (Lolium perenne L.) infected with the endophyte Epichloë festucae var. lolii (also termed LpTG-1). Ingestion causes a neurological syndrome in grazing livestock called ryegrass staggers disease. To enable the rapid development of new forage varieties, the toxicity of lolitrem B and its biosynthetic intermediates needs to be established. However, most of these indole diterpenes are not commercially available; thus, isolation of these compounds is paramount. A concentrated endophyte-infected perennial ryegrass seed extract was subjected to silica flash chromatography followed by preparative HPLC and purification by crystallization resulting in lolitrem B and the intermediate compounds lolitrem E, paspaline and terpendole B. The four-step isolation and purification method resulted in a 25% yield of lolitrem B. After isolation, lolitrem B readily degraded to its biosynthetic intermediate, lolitriol. We also found that lolitrem B can readily degrade depending on the solvent and storage conditions. The facile method which takes into consideration the associated instability of lolitrem B, led to the purification of indole diterpenes in quantities sufficient for use as analytical standards for identification in pastures, and/or for toxicity testing in pasture development programs.

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 Correlation of Ergovaline and Lolitrem B Levels in Endophyte-Infected Perennial Ryegrass (Lolium Perenne)

2001 ◽  
Vol 13 (4) ◽  
pp. 323-327 ◽  
Author(s):  
Jeannette T. Hovermale ◽  
A. Morrie Craig
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
High Performance ◽  
Clinical Signs ◽  
Strong Positive Correlation ◽  
State University ◽  
Lolitrem B ◽  
Toxic Alkaloids ◽  
Oregon State University

The varieties of perennial ryegrass ( Lolium perenne) infected with the endophytic fungus Neotiphodium lolii contain several classes of toxic alkaloids, including ergopeptide alkaloids and lolitrem alkaloids. Lolitrem B, a potent tremorgen, is generally considered to be the predominant alkaloid in endophyte-infected perennial ryegrass. Ergovaline, a vasoconstrictor normally associated with endophyte-infected tall fescue ( Festuca arudinacea), is also present in endophyte infected perennial ryegrass. Clinical signs of animals ingesting endophyte-infected perennial ryegrass are consistent with the presence of lolitrem B. However, clinical signs normally associated with ergovaline poisoning are not usually observed in animals ingesting endophyte-infected perennial ryegrass. A survey was conducted to quantitate both lolitrem B and ergovaline in 459 perennial ryegrass straw samples received at the Oregon State University College of Veterinary Medicine. Samples were analyzed for each alkaloid using separate high-performance liquid chromatography analyses. A strong positive correlation between the 2 alkaloids ( r2 = 0.7335) was observed, especially in the samples containing <3,000 ppb (ng/g) lolitrem B. The threshold levels above which clinical signs typically occur are 2,000 ppb lolitrem B and 300–400 ppb ergovaline. All of the samples analyzed contained <425 ppb ergovaline.

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