Files
Abstract
The genetic selection for heavy muscle gain and fast growth in broilers has been linked to the increased prevalence of bone diseases and leg problems. Meanwhile, coccidiosis which is caused by Eimeria spp., has become one of the most economically impactful diseases in poultry production. In this study, we firstly reported that Eimeria-infected birds had high levels of oxidative stress and lower antioxidant capacity in the bone marrow, Eimeria-infected birds had lower bone mineral content, density, and slower bone formation. The second experiment showed that other than malnutrition, inflammation-mediated osteoclast activity attributed to bone mineral loss during Eimeria infection. Meanwhile, oxidative stress negatively correlated with bone formation rate. In order to further understand the interaction between oxidative stress and bone metabolism, we utilized in ovo and in vitro models to study induced oxidative stress on bone growth. Chicken primary mesenchymal stem cells (MSCs) were exposed to hydrogen peroxide (H2O2) to induce oxidative stress in vitro study. Microinjection of H2O2 into chicken embryos was used to induce systemic oxidative stress at early embryonic development. Both in vitro and in ovo studies showed that oxidative stress negatively regulated the expression of the osteogenic genes and inhibited bone formation in the chicken MSCs and embryo. In the last part of the study, fish oil was used as a dietary supplement to reduce performance loss due to coccidiosis in broilers. Fish oil supplementation enhanced intestinal barrier integrity and positively impacted bone mineral content and growth performance in broilers during coccidiosis. Taken altogether, our studies demonstrate that oxidative stress and inflammation are key factors that mediate bone homeostasis by suppressing bone formation and increasing bone resorption during Eimeria infection in broilers. With current studies, we provide a more accurate understanding of bone homeostasis, and more evidence to uncover the pathology of the chicken bone disorder.