Dietary supplementation of artificial sweetener and capsicum oleoresin as a strategy to mitigate the negative consequences of heat stress on pig performance.

Pigs exposed to elevated ambient temperatures exhibit reduced daily gain, alterations in muscle and fat deposition, and decreased health. Negative aspects of gastrointestinal (GI) function, integrity and permeability also occur. High intensity sweeteners can ameliorate the negative effects of heat stress (HS) by increasing GI glucagon-like peptide (GLP)-2 production while capsicum oleoresin has been shown to reduce inflammatory response. Effects of an artificial high intensity sweetener and capsicum oleoresin (CAPS-SUC; TakTik X-Hit, Pancosma, Switzerland) on growth performance of pigs were examined. Forty-eight pigs (12 weeks of age, 43.2 kg +/- 4.3 kg) were assigned to six treatments: thermoneutral conditions (21 degrees C +/- 1.1 degrees C; 40% to 70% relative humidity) fed ad libitum with (TN+) or without supplement (TN-), heat stress (35 degrees C +/- 1 degrees C; 20% to 40% relative humidity) fed ad libitum with (HS+) or without supplement (HS-), and thermoneutral conditions pair-fed to HS intake with (PFTN+) or without supplement (PFTN-). Supplementation (0.1g/kg feed) began 2 days prior to the 3-day environmental treatment period. Body weights and blood samples were collected on day -1 and day 3. Rectal temperature (RT) and respiration rate (RR) were measured thrice daily and feed intake (FI) was recorded daily. Intestinal sections were collected for histology. Pigs in HS conditions exhibited increased RT (~1.2 degrees C) and RR (~2.7-fold) compared to TN and PFTN groups (P < 0.01). HS+ animals had increased RR when compared to HS- animals (P < 0.02). Heat stress decreased FI compared to TN. HS and PFTN decreased (P < 0.05) average daily gain (ADG) compared to TN. Supplement did not alter body weight gain. HS and PFTN decreased (P < 0.05) Gain:Feed compared to TN during environmental treatment. Supplementation with CAPS-SUC increased Gain:Feed by 0.12 (P < 0.05). Circulating glucose concentrations tended to decrease in CAPS-SUC vs. non-supplemented HS and PFTN animals (P