Detection of endophyte toxins in the imported perennial ryegrass straw.

The research article examines the impact on cattle and horses of toxins found in endophytes in imported perennial ryegrass straw.

Introduction

• The study was conducted between 1997 to 1999.
• The researchers documented 29 cases of disorders in horses and cattle that were fed imported perennial ryegrass straw.
• The straw was majorly imported from the USA.
• The symptoms resembling ryegrass staggers, however, disappeared after the straw diet was removed from the animals.

Endophyte Detection

• The researchers discovered endophytic hyphae in all the examined straw samples.
• These endophytes were believed to be responsible for the clinical cases of disorder among the animals.

Toxin Concentration Measurement

• The concentrations of Lolitrem B detected in straw samples ranged between 972 and 3740 ppb.
• Similiarly, concentrations of Ergovaline noticed were between 355 and 1300 ppb.

Key Findings & Implications

• The study found that despite the concentrations of Lolitrem B being lower than the toxic threshold proposed by Oregon State University in the majority of the cases, its presence still appeared to have negative effects.
• This suggests that concentrations of Lolitrem B lower than the proposed toxic threshold might still cause disorders in sensitive individuals.
• This finding raises important implications for the safe importation and use of perennial ryegrass straw in livestock feed, as well as the threshold levels currently considered to be non-toxic.