Aflatoxin B1 Impairs Bone Mineralization in Broiler Chickens

Aflatoxin B1 (AFB1), a ubiquitous mycotoxin in corn-based animal feed, particularly in tropical regions, impairs liver function, induces oxidative stress and disrupts cellular pathways, potentially worsening bone health in modern broilers. A 19-day experiment was conducted to investigate the effects of feeding increasing levels of AFB1-contaminated feed (<2, 75-80, 150, 230-260 and 520-560 ppb) on bone mineralization markers in broilers (n = 360). While growth performance remained unaffected up to Day 19, significant reductions in tibial bone ash content were observed at levels exceeding 260 ppb. Micro-computed tomography results showed that AFB1 levels at 560 ppb significantly decreased trabecular bone mineral content and density, with a tendency for reduced connectivity density in femur metaphysis. Moreover, AFB1 above 230 ppb reduced the bone volume and tissue volume of the cortical bone of femur. Even at levels above 75 ppb, AFB1 exposure significantly downregulated the jejunal mRNA expressions of the vitamin D receptor and calcium and phosphorus transporters. It can be concluded that AFB1 at levels higher than 230 ppb negatively affects bone health by impairing bone mineralization via disruption of the vitamin D receptor and calcium and phosphorus homeostasis, potentially contributing to bone health issues in broilers.