Response of tibia bone morphology, biomechanics and minerals to Organic Hawthorn (Crataegus tanacetifolia) Fruit Vinegar application in broiler chickens exposed to cyclic heat stress

This study aimed to determine the effects of adding different doses of organic hawthorn fruit vinegar (HFV) to the drinking water of male broilers (Ross 308) reared under cyclic heat stress (CHS) on tibia bone morphology, biomechanics, and minerals. Broilers were distributed into six groups based on a 2 × 3 factorial design, testing two ambient temperatures (24 and 35°C CHS for 8 h/day starting from day 21) and three HFV levels (0, 2, and 4 ml/L). Cyclic heat stress had no effect on the morphological and biomechanical properties of the tibia bone, except for a decrease in cortex thickness (P < 0.05). However, CHS significantly decreased the bone Ca, P, Mg, Cu, Zn, Mn, and K levels, while increasing the Fe levels (P < 0.01). The addition of 2 and 4 ml/L HFV had no effect on the morphological and biomechanical properties of the tibia bone (P > 0.05), except for an increase in bone diameter with 2 ml/L HFV (P < 0.05). HFV additions were not sufficient to increase the Ca level decreased by CHS, and the tibia bone Ca level of birds under CHS decreased further with HFV additions (P < 0.01). Conversely, 2 ml/L HFV increased Mg levels, and both 2 and 4 ml/L HFV increased Cu, Fe, Zn, and Mn levels, whereas P levels decreased (P < 0.01). K level decreased with 2 ml/L HFV and increased with 4 ml/L HFV supplementation. In conclusion, HFV supplementation has positive effects on bone mineralization in broilers exposed to HS and can be used up to 4 ml/L to mitigate the negative effects of heat stress.