Changes in the content of edible and non-edible components and distribution of tissue components in cockerels and capons

Magdalena Zawacka,Danuta Michalik,Michal Gesek,Daria Murawska

doi:10.5424/sjar/2018161-11834

Abstract

The aim of this study was to determine the effects of castration and age on the content of edible and non-edible components, and the distribution of tissue components in the carcasses of cockerels and capons. The study was conducted on 200 birds (Green-legged Partridge), divided into two sex categories (with 5 replications per group and 20 birds per replication), raised to 28 wk of age. At 8 wk of age, 100 birds were surgically castrated and afterwards at 12 wk of age and at four-wk intervals, 10 intact cockerels and 10 capons were selected randomly and slaughtered. Cockerels, compared with capons, were characterized by a higher proportion of edible components at 24 and 28 wk of age, and a more desirable carcass tissue composition due to a higher content of lean meat in total body weight (BW). Capons had higher abdominal fat content than cockerels, which resulted in a higher percentage of non-edible components in their BW at 24 and 28 wk of age. Differences in the distribution of lean meat in the carcass were noted from 20 wk of age in both castrated and intact birds. The content of breast muscles increased in capons, and the content of leg muscles (thigh and drumstick) increased in cockerels. The results of this study indicate that in view of the optimal lean meat content of the carcass and the optimal distribution of major tissue components, Green-legged Partridge capons should be fattened for a maximum period of 24 wk.

Highlights

In Europe, the meat of capons is appreciated by consumers for its tenderness and flavor, and it is more expensive than meat from broiler chickens and organic chickens (Muriel Durán, 2004; Franco et al, 2016)
The results of this study indicate that in view of the optimal lean meat content of the carcass and the optimal distribution of major tissue components, Green-legged Partridge capons should be fattened for a maximum period of 24 wk
At 24 and 28 wk of age, the weight of edible components was higher in cockerels than in capons (p≤0.05), which was reflected in the content of edible and non-edible components expressed as a percentage of total body weight (BW) (Table 2)

Summary

Introduction

In Europe, the meat of capons (surgically castrated male chickens) is appreciated by consumers for its tenderness and flavor, and it is more expensive than meat from broiler chickens and organic chickens (Muriel Durán, 2004; Franco et al, 2016). The cited authors demonstrated that chickens castrated at an early age (3 wk) had higher body weight (BW) and a higher percentage of breast muscles in the carcass than intact males, whereas such a correlation was not observed in birds caponized at a later age (12 wk). A higher proportion of adipose tissue in the form of abdominal and peri-intestinal fat contributes to a higher content of non-edible components in the total BW of birds. The total weight of edible components (lean meat, skin and fat, giblets) and non-edible components (slaughter offal and bones) in poultry carcasses is of key importance for both producers and consumers (Murawska et al, 2011; Murawska, 2013a,b). The above proportions are much more desirable in broiler chickens than in layer-type chickens (Murawska et al, 2005; Murawska & Bochno, 2007)

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