Merino ewes ( n = 36, 40 kg, n = 6 per group) were maintained at thermoneutral (TN, n = 18, 21 °C) or cyclical HE ( n = 18, 18-43 °C) conditions for 21 days, and supplemented with either 0 (control), 2 or 4 g betaine/day. 
THERM