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.

A metabolite of leucine (β-hydroxy-β-methylbutyrate) given to sows during pregnancy alters bone development of their newborn offspring by hormonal modulation

“…The measuring head loaded bone samples with a constant speed of 10 mm/min until fracture as it was described previously [29]. The ultimate endurance was determined as the force causing bone fracture and the maximum elastic strength as maximal force under elastic (reversible) deformation of bone [27, 30]. The registered strength data were also normalized to bone geometry and expressed as a ratio of recorded force and the mid-diaphysis cross section area.…”

“…The registered strength data were also normalized to bone geometry and expressed as a ratio of recorded force and the mid-diaphysis cross section area. Moreover, on the basis of measured geometric and mechanical traits the material properties of the mid-diaphyseal fragment of the bone were calculated with method described previously [30]. These traits describe the specific mechanical properties of midshaft cortical tissue and are independent of the bone size and the conditions under which the strength tests were conducted.…”

“…These traits describe the specific mechanical properties of midshaft cortical tissue and are independent of the bone size and the conditions under which the strength tests were conducted. Bending moment can be described as a yield load adjusted to the bone length and it indicates bone elastic load capability [30]. The elastic stress reflects the elastic strength of midshaft cortical bone, the ultimate stress is equal to the maximum stress a bone can withstand in bending before fracture [30, 31].…”

Effect of Breed and Caponisation on the Growth Performance, Carcass Composition, and Fatty Acid Profile in the Muscles of Greenleg Partridge and Polbar Breeds

“…Another native breed that can be used for production of capons and, simultaneously, high-quality poultry meat is the Polbar (Pb) breed (Gryzińska et al, 2014). The result of caponisation of Pb cocks is interesting, since this is a synthetic breed originating from crossing of the Greenleg Partridge breed with cocks of the heavy breed Barred Plymouth Rock (Muszyński et al, 2017).…”

Analysis of bone mineralization, osteometric and mechanical properties in turkey hens at slaughter demonstrates a influence of housing system but not stocking density

“…Bone structural properties (stiffness, yield strength, ultimate strength, elastic energy and work to fracture) were determined on the basis of recorded force-displacement curves. Whole-bone material properties were calculated on the basis of determined structural properties and geometry of the bone diaphysis using engineering beam-theory equations (Muszy ski et al 2017). The ascertained structural properties included: elastic stress, elastic strain, Young modulus, ultimate strain and ultimate stress.…”