Perennial ryegrass endophyte effects on plasma prolactin concentration in dairy cows

Bluett, S. J.; Kolver, E.S.; Auldist, M.J.; Thom, E. R.; Davis, Stephen R.; Farr, V. C.; Tapper, B.A.

doi:10.1080/00288233.2003.9513523

Cited by 11 publications

(3 citation statements)

References 27 publications

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“…Shoots and roots of L. arundinaceum infected with Neotyphodium coenophialum E WT had nearly 10% more total phenols than their E – counterparts. Moreover, the response to endophyte infection on L. arundinaceum phenol content differed according to genotype, the type of tissue investigated (shoots and roots), site conditions such as shading and defoliation, and abiotic stress factors such as phosphorus deficiency. , Ponce et al found that endophyte infection of L. multiflorum influences both the quantity and the variety of polyphenols. In contrast, the present study indicates that endophytic infection can have either positive or negative effects on phenol content in L. perenne based on the strain of endophyte involved.…”

Section: Resultsmentioning

confidence: 99%

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Influence of Fungal Endophyte Infection on Phenolic Content and Antioxidant Activity in Grasses: Interaction between Lolium perenne and Different Strains of Neotyphodium lolii

Qawasmeh

Obied

Raman

et al. 2012

J. Agric. Food Chem.

100

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Lolium perenne is a major forage and turf grass, which is often naturally infected with a "wild-type" strain (E(WT)) of the fungal endophyte Neotyphodium lolii , establishing a symbiotic relationship. In this study, the impacts of different strains wild type E(WT), AR1 (E(AR1)) and AR37 (E(AR37)), of N. lolii on the phenolic profile, phenolic content, and antioxidant capacity of L. perenne were examined. Samples could be ranked according to their phenol content as follows: E(AR1) > E(AR37) ≥ E(-) > E(WT). Radical-scavenging assays showed the same relative ranking of extracts. Flavonoid glycosides and hydroxycinnamic acids were the most abundant polyphenols in L. perenne extracts. Chlorogenic acid and its derivatives were the major compounds responsible for the antioxidant activity. Infection with N. lolii significantly influenced L. perenne phenolic content and antioxidant activity. In conclusion, changes in phenolic composition were merely quantitative. Endophyte infection can have zero, positive, or negative effect on phenol content depending on the endophyte strain.

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Section: Resultsmentioning

confidence: 99%

“…ABTS •+ Radical-Scavenging Assay. The stock solution of ABTS •+ was prepared as described previously 23 by mixing ABTS •+ reagent (7.0 mM) with potassium persulfate (2.45 mM). The solution was kept in darkness overnight.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Influence of Fungal Endophyte Infection on Phenolic Content and Antioxidant Activity in Grasses: Interaction between Lolium perenne and Different Strains of Neotyphodium lolii

Qawasmeh

Obied

Raman

et al. 2012

J. Agric. Food Chem.

100

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“…Several reports (Table 1) have shown a depression in circulating prolactin concentration as a response to ergovaline intake from endophyte-infected ryegrass. However, using dairy cattle, Bluett et al (2003a) provided evidence that serum prolactin concentration may not be useful as an indicator of an ergovaline effect on animal production because it has not been well correlated with effects on liveweight gains in animals (Aldrich et al 1993). In essence, a suppressed prolactin concentration is a good indicator of ergovaline intake but not of the level of intake, or magnitude of other responses.…”

Section: Ergovaline Intakementioning

confidence: 99%

Ergovaline, an endophytic alkaloid. 2. Intake and impact on animal production, with reference to New Zealand

Nicol

Klotz

2016

Anim. Prod. Sci.

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Abstract. On the basis of published reports, the daily intake of the alkaloid ergovaline from the consumption of endophyte-containing ryegrass in New Zealand ranges from 0.008 to 0.287 mg ergovaline/kg LW 0.75 .day. Most of the reports are based on the use of standard endophyte-containing ryegrass and, thus, it is difficult to disassociate the impact of ergovaline consumption from that of lolitrem B. However, physiological effects of ergovaline consumption, such as reduced circulating prolactin concentration, vasoconstriction and elevated core temperature, have been detected at fairly low ergovaline intake, whereas decreased feed intake, liveweight gain and milk production have not generally been observed in animals at an intake below 0.07 mg ergovaline/kg LW 0.75 .day. Intakes above this value represent only 17% of published values. There are insufficient data to suggest a threshold ergovaline intake associated with heat stress with animal-welfare implications. The relationship between published ergovaline intake and the corresponding ergovaline concentration in pasture is poor (R 2 = 0.48), but on average an intake of 0.07 ergovaline/kg LW 0.75 .day is associated with an ergovaline concentration in ryegrass of 0.70 mg/kg DM. About 16-18% of published ergovaline concentrations in ryegrass pasture exceed this value. The ergovaline concentration in ryegrass is greater in the basal parts of the plant than in the leaf and during the late summer-autumn than in spring. Animals grazing in the lower sward horizons (horizontal grazing plane) are more at risk of high ergovaline intake, although the reduction in grazing intake induced by grazing at low pasture height aids in limiting ergovaline intake. As pasture growth rates decline in late summer, supplementary feed may be used to maintain stocking rate and, if such feeds have zero ergovaline concentration, they serve to dilute the mean dietary ergovaline intake. Ergovaline-containing ryegrass pastures are widely used in New Zealand. It appears that farmers consider the risks of depressed animal production on these pastures to be less than the benefits ergovaline bestows through its deterrent effect of specific insect attack and thus greater survival and pasture persistence.

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Managing Ryegrass‐Endophyte Toxicoses

Fletcher

2005

Neotyphodium in Cool‐Season Grasses

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Perennial ryegrass endophyte effects on plasma prolactin concentration in dairy cows

Cited by 11 publications

References 27 publications

Influence of Fungal Endophyte Infection on Phenolic Content and Antioxidant Activity in Grasses: Interaction between Lolium perenne and Different Strains of Neotyphodium lolii

Influence of Fungal Endophyte Infection on Phenolic Content and Antioxidant Activity in Grasses: Interaction between Lolium perenne and Different Strains of Neotyphodium lolii

Ergovaline, an endophytic alkaloid. 2. Intake and impact on animal production, with reference to New Zealand

Managing Ryegrass‐Endophyte Toxicoses

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