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Simple SummaryImproving 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.AbstractThe 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.

Claviceps purpurea infects the seed heads of cereal grains and grasses and produces ergopeptine alkaloids that cause hyperthermia and agalactia in cattle during periods of heat stress. A field experiment was undertaken to examine the effects of ergopeptine alkaloids found in barley on thermal status of dairy cattle during periods of heat stress. Production end points were also measured to identify the effect of the change in thermal status. Contaminated barley screenings containing known levels of ergopeptine alkaloids were fed to lactating Holstein cattle (10 microg total ergopeptine alkaloids/kg BW/day) for 10 days during summer heat stress. Air temperature increased 14.4 C during the first 8 days of treatment and then declined the same during the last 2 days. Extreme daily values for rectal temperature and respiration rate, using averages of all animals, showed maximum increases of 2.3 C and 56.8 breaths/minute, respectively, during this period. Group afternoon milk production decreased 2 kg/day during the heat stress period, with no measurable change in feed intake. A greater level of hyperthermia occurred in cattle consuming the diet with ergopeptine alkaloids, with only marginal symptoms of ergot toxicosis reflected in feed intake and milk production. Therefore, the ergopeptine alkaloid dose used in this study represents a level for minimal induction of the ergot toxicity response.