Preliminary estimates of genetic parameters for bone geometry, strength, and metabolism traits and their relationship with walking ability in turkeys (Meleagris gallopavo)

Impaired walking ability is a persistent concern in commercial turkeys, affecting both animal welfare and productivity. Although bone geometry, strength, and metabolism contribute to overall walking ability, the genetic background of these traits remains poorly characterized. Therefore, the main objectives of this study were to estimate genomic-based variance components and genetic parameters for bone geometry, strength to fracture, and collagen turnover metabolism, and to evaluate their relationship with walking ability in domestic turkeys ( Meleagris gallopavo ). Phenotypic data were collected from 722 male turkeys raised under experimental conditions across three repetitions. Birds were sampled at either 8, 12, and 18–19 weeks of age, and traits related to bone geometry and bone strength were measured. Bone geometry traits included weight, length, midpoint, anterior-posterior diameter, and medial-lateral diameter; and bone strength traits included peak force and work to fracture, which were recorded for the femur (n = 339), tibia (n = 177), and humerus (n = 167). Additionally, a collagen turn-over marker, pyridinoline (PYD) and welfare-related traits with repeated records, including gait score (GS; n = 2,215), footpad lesions (n = 2,216), head lesions (n = 2,216), and body weight (BW; n = 704) were also collected. All 722 birds were genotyped using a SNP chip panel containing 13,491 SNPs after quality control. Variance components were estimated using Bayesian animal models via Gibbs sampling in the GIBBSF90+ software. Heritability estimates across bone traits ranged from 0.11 ± 0.08 to 0.48 ± 0.27 for bone geometry traits and from 0.09 ± 0.08 to 0.29 ± 0.25 for bone strength traits. PYD presented a heritability of 0.17 ± 0.10. Our preliminary results suggest that bone geometry is moderately heritable with variable genetic correlations with bone strength, suggesting that geometry-based selection alone could be insufficient for improving skeletal health in turkeys. The preliminary estimates of heritability and phenotypic correlations observed for PYD suggest its potential as a phenotype to enhance selection for skeletal integrity in turkeys. However, future research using larger sample sizes and diverse turkey populations is recommended to validate these findings.