Cellular and mitochondrial adaptation mechanisms in the colon of lactating dairy cows during hyperthermia.Heat stress causes barrier dysfunction and inflammation of the small intestine of several species.  However, less is known about the molecular and cellular mechanisms underlying the response of the bovine large intestine to hyperthermia.  Eighteen lactating Holstein dairy cows were kept under constant thermoneutral conditions (16°C and 68% relative humidity (RH); temperature-humidity-index (THI) = 60) for 6 d (period  1) thermoneutral condition with ad libitum feeding (TNAL; 16°C, RH = 68%, THI = 60),  2) heat-stressed condition (HS; 28°C, RH = 50%, THI = 76) with ad libitum feeding, or 3) pair-feeding at thermoneutrality (TNPF; 16°C, RH = 68%, THI = 60) for another 7 d (period 2). 
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