In pursuit of a better broiler: tibial morphology, breaking strength, and ash content in conventional and slower-growing strains of broiler chickens

• Published in: Poultry science 2022-04, Vol.101 (4), p.101755-101755, Article 101755
• Main Authors: Santos, Midian N., Widowski, Tina M., Kiarie, Elijah G., Guerin, Michele T., Edwards, A. Michelle, Torrey, Stephanie
• Format: Article
• Language: English
• Subjects: Animals; ash content; Bone and Bones; bone health; bone strength; chicken; Chickens; Diet; Female; genetic; growth rate; lameness; Male; MANAGEMENT AND PRODUCTION; mineralization; morphometry; slow-growth; tibia; Tibia - anatomy & histology
• ISSN: 0032-5791; 1525-3171
• DOI: 10.1016/j.psj.2022.101755

This study was conducted to determine the differences in bone traits in 14 strains of broiler chickens differing in growth rate. The strains encompassed 2 conventional (CONV; ADG0-48 >60 g/d) and 12 slower-growing (SG) strains classified as FAST (ADG0-62 = 53–55 g/d), MOD (ADG0-62 = 50–51 g/d), and SLOW (ADG0-62 0.69). At TW2, category (P > 0.50) had no effect on tibial diameter, yet CONV birds had the shortest tibiae (P < 0.001). The CONV birds had greater TBS:BW ratio than FAST and MOD birds at both TWs 1 and 2 (P < 0.039) and similar ash content as the other categories at TW2 (P > 0.220). At 48 d of age, CONV birds had the greatest absolute TBS (P < 0.003), yet lower TBS:BW ratio than SLOW birds (P < 0.001). Tibiae from CONV birds were longer than MOD and SLOW birds, and thicker in diameter than the other categories, yet CONV birds had the lowest dimensions relative to BW (P < 0.001) at 48 d, indicating a negative association between accelerated growth and tibial dimensions. These results indicate that differences in functional abilities among categories may be due to differences in morphometric traits rather than differences in bone strength and mineralization.