Thermotolerance of Broiler Chicks Ingesting Dietary Betaine and/or Creatine

SIMPLE SUMMARY: Improving broiler performance is still an essential task in animal production, especially under certain environmental challenge conditions. Heat stress is among the first and crucial limiting factors of the development of poultry production in warm regions. Betaine (B) and creatine (C) are seemingly two promising additives that showed enhancement in water metabolism in several animal species. Despite the clear beneficial effect of B and/or C on water metabolism, limited information is available about their use and effect on performance and thermophysiological responses of broiler chicks exposed to heat stress challenge. In view of the above consideration and in order to improve the productivity of broiler chickens, the present study was designed to examine the potential alteration in water metabolism in broiler chicks treated with B and/or C under thermoregulation challenge, which may contribute to the ongoing efforts to improve broiler chicken production. Under the current study conditions, the results demonstrated that performance and carcass parameters measured were not affected by B and/or C supplementation by the end of the rearing period. In light of the improved thermoregulatory performance and water balance indicators, it seems that B and/or C have successfully improved water holding capacity and therefore helped in enhancing thermo-tolerance. ABSTRACT: The present study aimed to assess the effect of dietary betaine (B) and/or creatine (C) on performance and thermoregulatory responses of broiler chicks. Indian River broiler chicks, fitted with compact thermosensors, were reared to market age (five weeks). The chicks were randomly distributed into four treatment groups, in a 2 × 2 factorial arrangement of treatments—basal control diet (Control group: CONT; B−/C−); 1 g betaine/kg feed (Betaine group: BETA; B+/C−), 1.2 g creatine monohydrate/kg feed (Creatine group: CRET; B−/C+), and combination (Betaine and Creatine group: COMB; B+/C+) of both supplements. At 31 days of age, 20 chicks from each group were exposed to acute heat stress (A-HS) for 3 h (34.45 ± 0.20 °C), and hemogramic profiles were screened before and after. Performance parameters (feed intake, body weight gain, and feed conversion ratio) were reported on a weekly basis, and carcass meat quality was evaluated at the end of experiment. Redness of breast was higher due to B and C treatments separately than the CONT group (B by C interaction; p < 0.05). Compared to the CONT, dietary supplements alleviated hyperthermia responses, with B alone being more efficient than C or COMB treatments. The mitigation of hyperthermia is likely mediated by enhancement of water balance indicators. Although not efficient in improving growth performance, dietary B and/or C are efficient in improving thermophysiological performance and survival of finishing broiler chicks under A-HS.