Abstract
Modern-day broilers are prone to disproportionate bone development besides beneficial broiler performance parameters. Cardinally, global concerns on production and welfare parameters are associated with altered intestinal health and bone homeostatic disturbances pertaining to oxidative stress and inflammation caused by coccidiosis. Nonetheless, lipopolysaccharides (LPS) released into systemic circulation during gut barrier integrity disruption also inhibits bone formation. The current study focused on bone health following the co-challenge of LPS and coccidia in broilers. Cobb500 male broilers were randomly assigned to 6 treatments (T1-T6) and 5 replicates with 12 birds in each pen. Mixed Eimeria spp., 12,500 E. maxima, 12,500 E. tenella, and 62,500 E. acervuline, were inoculated orally on day 14 for all treatments except for the non-challenged control (NC or T1) group. On the same day, LPS was injected intraperitoneally to T3 and T4 at 1 and 2 mg/kg, respectively. T5 and T6 had intraperitoneal injections of LPS at 1 and 2 mg/kg, respectively, on both days 14 and 18. Data obtained from Dual Energy X-ray Absorptiometry (DEXA) showed a significantly lower bone mineral content for the challenged treatments (T2-T6) compared to the non-challenged treatment. Furthermore, bone mineral density (BMD) for 6 days post Eimeria spp. inoculation (DPI) was significantly lower in T4, T5, and T6. Interestingly, micro-CT data revealed that tibial cortical bone porosity parameters such as closed pores number, volume of open pores, and total volume of pores at DPI 12 were significantly lower for T4 and T6. Moreover, sclerostin (SOST) levels in serum were significantly higher in T6, showing an evidence on aberrations in bone homeostasis following coccidiosis and LPS challenge. Reinforcing the above statement, calcein labelling for dynamic bone histomorphometry also revealed similar findings. Finally, the current study shows that higher doses of LPS and concomitant coccidiosis adversely affect bone development in broilers which improves our understanding on gut-bone axis besides deciphering novel findings on concomitant effects of both challenge candidates.