Differences in broiler bone, gut, and tissue mineral parameters, as influenced by broilers grouped based on bodyweight

Context: Variation in bodyweight is an undesirable feature in broiler production. Compositional differences between high- and low-bodyweight (BW) chicks in bone parameters and tissue mineral concentrations may provide insight into underlying causes of variation in BW. Aims: This study aimed to investigate differences in bone measurements, tissue mineral concentrations, and gut parameters of Ross 308 male broiler chicks with identical diet and environmental conditions, but with distinct BW on Day 21 (D21). Methods: A 3-week growth study was conducted involving 40 male, day-old chicks from the Ross 308 line. Chicks were reared in a deep-litter house with a controlled environment and the same commercial diet. On D21, BW data collected from chicks were used as a criterion to rank them into high- and low-BW groups (n = 11/group). Retrospective BW measurements were compared between groups. Birds were selected for assessing bone parameters, liver mineral profile, gut pH, gizzard neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents. Key results: Retrospective BW measurements among the high- and low-BW groups showed a consistent difference in BW between the two groups in early life. Tibial concentrations of manganese and strontium were significantly (P < 0.05) higher in the low-weight (LW) group relative to the high-weight (HW) group. Concentrations of manganese, cadmium and caesium in the liver tissue showed significant differences, with the LW group having higher concentration of these trace elements. The LW chicks had lower gizzard digesta pH, higher gizzard NDF and a statistical tendency for higher ADF concentrations compared to the HW group. Conclusions and implications: In summary, broilers ranked on the basis of D21 BW showed differences in tibial bone, gut, and tissue mineral parameters. The LW group had lower gizzard pH and higher gizzard fibre content than did the HW group, which may be attributed to factors such as behavioural activities relating to more litter consumption among the LW group than the HW group.