Journal article

Perennial Ryegrass Alkaloids Increase Respiration Rate and Decrease Plasma Prolactin in Merino Sheep under Both Thermoneutral and Mild Heat Conditions

Michelle LE Henry, Stuart Kemp, Iain J Clarke, Frank R Dunshea, Brian J Leury

TOXINS | MDPI | Published : 2019


A study was undertaken to determine the effects of feeding two levels of perennial ryegrass alkaloids (nil vs. moderate) under two climatic conditions. Alkaloids were fed via endophyte-infected perennial ryegrass seed and hay. Twenty-four Merino ewe weaners (six months, initial BW 32 ± 1.7 kg) were used in a study that lasted for 21 days after 14 days of adaptation. Sheep were fed either a control or alkaloid (Alk, 110 μg/kg LW ergovaline and 75 μg/kg LW lolitrem B) supplemented diet. Sheep were exposed to either constant thermoneutral (TN, 21-22 °C, 49% RH) or mildly heated (HS, 33 °C 1000-1500 h, 28% relative humidity) conditions. Dietary Alk and HS reduced dry matter intake (DMI) (p < 0.0..

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