title: Effect of caponization on performance and quality characteristics of long bones in Polbar chickens.
abstract: The effect of caponization on the mechanical properties of Polbar chicken bones was the subject of investigation. The biomechanical strength of bones and the risk of their deformation or fracture were determined on the basis of their geometric, structural, material, and densitometric properties. Eight-week-old cockerels of Polbar breed were surgically castrated and then fattened until the 24th week of life. It was observed that caponization did not influence the weight and length of either of the long bones. It did however significantly reduce their ash content and the Ca and P contents in their femur, and P content in their tibia. Dual energy x-ray absorptiometry densitometry revealed that bone mineral content of the mid-diaphyseal part of both bones were reduced. Similarly, the bone tissue density of bones decreased. Caponization influenced the bone's geometric structure increasing the internal and external diameters of the bones. The bone cross-sectional area was greater in capons, and, consequently, the cross-sectional moment of inertia and the radius of gyration significantly increased. However, the relative wall thickness and cortical index were not altered. The three-point bending tests revealed the negative effect of caponization on the mechanical endurance of bones. Yield strength, Young modulus, and yield stress, characterizing the strength of the bone's material, decreased in capons. That suggests a higher risk of permanent deformation as capon bones become less elastic. Concluding, caponization negatively influenced the quality characteristics of Polbar chicken long bones.
authors: Department of Physics, Faculty of Production Engineering, University of Life Sciences in Lublin, Lublin, Poland siemowit.muszynski@up.lublin.pl.
authors: Siemowit
authors: S
authors: Muszyński
authors: Institute of Animal Nutrition and Bromatology, University of Life Sciences in Lublin, Lublin, Poland.
authors: Małgorzata
authors: M
authors: Kwiecień
authors: Department of Animal Physiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Lublin, Poland.
authors: Ewa
authors: E
authors: Tomaszewska
authors: Department of Physics, Faculty of Production Engineering, University of Life Sciences in Lublin, Lublin, Poland.
authors: Izabela
authors: I
authors: Świetlicka
authors: Department of Comparative Anatomy and Anthropology, Maria Curie-Skłodowska University, Lublin, Poland.
authors: Piotr
authors: P
authors: Dobrowolski
authors: Department of Biological Basis of Animal Production, University of Life Sciences in Lublin, Lublin, Poland.
authors: Kornel
authors: K
authors: Kasperek
authors: Department of Biological Basis of Animal Production, University of Life Sciences in Lublin, Lublin, Poland.
authors: Grażyna
authors: G
authors: Jeżewska-Witkowska
mesh_terms: D015502:Absorptiometry, Photon / Q000662:veterinary; D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density; D002645:Chickens / Q000502:physiology*; D005269:Femur / Q000737:chemistry*; D008297:Male; D009919:Orchiectomy / Q000662:veterinary*; D011897:Random Allocation; D013977:Tibia / Q000737:chemistry*
keywords: bone; caponization; cockerels; mechanical properties; the Polbar breed