Effect of lipopolysaccharides and mixed Eimeria spp. challenge on performance and bone development in broilers.

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.