Impact of Phytobiotic Supplementation Administered in Drinking Water on Meat Quality in Heat-Stressed Broilers

This study evaluated the effects of a phytobiotic additive, hawthorn fruit extract (HFE), administered via drinking water on meat quality of broilers subjected to heat stress (HS). A total of 300 one-day-old broiler chicks were distributed into six experimental groups according to a 2×3 factorial design after a one-week acclimation period, with five replicates of 10 chicks each. Chicks had ad libitum access to feed and water for the duration of the 42-day trial and were exposed to a 24-hour lighting program. HS decreased the b* color value of breast meat while increasing L* and a* values and pH of thigh meat. Cooking loss (CL) of both breast and thigh meat was reduced, whereas water-holding capacity (WHC) remained unaffected. HS did not significantly alter thiobarbituric acid-reactive substances (TBARS), total saturated fatty acids (ΣSFA), or total unsaturated fatty acids (ΣUFA), but decreased monounsaturated fatty acids (ΣMUFA) and increased emulsion stability (ES) and polyunsaturated fatty acids (ΣPUFA). Adding HFE to the drinking water did not influence breast meat pH or color intensity, but WHC improved in breast meat with 0.2 mL/L HFE and in thigh meat at both HFE concentrations. The 0.4 mL/L HFE dose increased ΣSFA and decreased ΣUFA and ΣPUFA levels, while ΣMUFA decreased at both HFE concentrations. Overall, HFE supplementation mitigated several adverse effects of HS, notably enhancing ES and reducing redness of thigh meat. These findings suggest that HFE can be an effective phytobiotic strategy to improve meat quality in broilers under thermal stress conditions.