Utilization of Bone Alkaline Phosphatase (BAP) and Tartrate Resistant Acid Phosphatase (TRAP) as Biomarkers of Eggshell Quality and Bone Metabolism in Broiler Breeders and Progeny.

Eggshell breakage and broiler bone disorders are major problems for the breeder and broiler industries which are linked to mineral metabolism and animal genetics. The purpose of this work was to discover the link between individual animal phenotypic differences in mineral metabolism against concentrations of novel plasma biomarkers including tartrate resistant acid phosphatase (TRAP) and bone alkaline phosphatase (BAP). A subset of hens were selected from a flock of Cobb 500 breeders with the best or worst eggshell quality based upon dual energy x-ray absorptiometry (DEXA) and specific gravity (SG). Breeders were defined as having good eggshell quality (SG ≥ 1.080), or poor eggshell quality (SG < 1.080). Progeny hatched from breeders with good or poor eggshell quality were reared to 2 week of age and blood and bone samples were obtained after euthanasia. In both breeders and progeny, plasma concentrations of BAP and TRAP were measured, and bone mineral density was evaluated by DEXA. Results showed that breeders selected for eggshell quality had significantly different plasma concentrations of BAP (Good = 326.5 pg/mL, Poor = 253.2 pg/mL), and TRAP activity (Good = 2203 U, Poor = 4985 U). Breeders selected for eggshell quality produced progeny with different bone breaking strength (Good = 1.61 kg/mm, Poor = 1.47 kg/mm), tibia ash (Good = 45.9%, Poor = 42.2%), plasma BAP (Good = 372.3 pg/mL, Poor = 312.4 pg/mL), and lower plasma TRAP activity (Good = 18010 U, Poor = 23590 U). These data suggest that there is a strong correlation between the eggshell quality of breeders, performance and bone strength of progeny, and plasma of concentrations of BAP and TRAP in both breeder hens and progeny.