Effects of hawthorn (Crataegus oxycantha) fruit extract on tibia bone properties in broiler chickens subjected to heat stress

The purpose of this study was to examine the effects on tibia morphology, biomechanics, and mineral levels of varying dosages of hawthorn (Crataegus oxyacantha) fruit extract (HFE) addition to experimentally heat-stressed broiler drinking water. A 2x3 factorial experimental design was used to randomly assign 300 one-day-old male broilers to six experimental groups. The experimental groups included three different HFE additions (0, 0.2, and 0.4 mL/L) and two different ambient temperatures (24 and 35 °C). Each experimental group consisted of five replicates, with 10 chicks (initial body weight 38±4 g) per replicate. The study results indicated that heat stress (IIS) led to a decline in tibia dry weight, length, wet weight, volume, Seedor index, cortex thickness, shear force and shear stress, while concurrently resulting in an increase in dry matter percentage (P<0.05). Heat stress led to a decline in the levels of calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), zinc (Zn) and potassium (K) (P<0.05). The addition of HFE in the drinking water of broiler chickens exposed to HS did not significantly affect the morphological and biomechanical properties of the tibia. However, tibial Ca levels increased with the addition of 0.2 mL/L HFE, while Mg and Zn levels were elevated at both 0.2 and 0.4 mL/L HFE concentrations compared to the control group (P<0.05). In contrast, Fe and Mn levels decreased with 0.2 mL/L HFE supplementation, and K levels were reduced at both supplementation levels compared to the control (P<0.05). The findings suggest that the addition of 0.2 mL/L HFE to the drinking water of heat-stressed broiler chickens may be an effective and recommended strategy to enhance bone quality characteristics.