Circulating (A) glucose (mg/dL) and (B) insulin (μIU/ mL) concentrations before (Pre), during, and after (Post) treatment in cows exposed to 1 of 4 treatments: ad libitum, 25% feed restriction (25FR), 50% feed restriction (50FR), and 50% of TMR replaced with wheat straw (50ST). a–cWithin day, means with different letters differ (P < 0.05).