Effect of Genotype on Slaughtering Performance and Meat Physical and Sensory Characteristics of Organic Laying Hens

Abstract

Slaughtering yields and some meat physical and sensorial parameters of laying hens reared under organic system production were studied. The hens belonged to both Italian dual-purpose breeds [Ermellinata di Rovigo (ER; brown eggshell) and Robusta Maculata (RM; brown eggshell)] as well as hybrid genotypes [Hy Line White 36 (white eggshell) and Hy Line Brown (brown eggshell)]. The birds were reared under organic farming system production from 24 to 44 wk of age, when they were slaughtered. They were reared throughout summer and autumn, and the temperature ranged from about 28 to 3 degrees C. Local breeds presented higher (P < 0.01) live BW and dressing percentage compared with hybrids. The RM and ER carcasses had (P < 0.01) the highest breast and leg (thigh and drumstick) percentage, respectively. The muscle-bone ratio of the Hy Line White 36 drumstick was lower (P < 0.05) than the RM ratio, whereas the other groups were intermediate. The ER breast presented the highest (P < 0.01) lightness value and the lowest (P < 0.01) final pH value compared with the other 3 groups. The breast meat significantly differed according to genotype for almost all the studied sensorial parameters (adhesivity, fibrousness, chewiness, solubility, juiciness, tenderness, shear resistance), with the exception of aroma and odor intensity. In the thigh, genotype significantly affected aroma, adhesivity, fibrousness, solubility, tenderness, and shear resistance.

Differences between spent hens of different genotype in performance, meat yield and suitability of the meat for sausage production

“…This could be explained by differences in dressing procedure. There was a difference between the two genotypes in the present study, which was not found by Rizzi et al (2007) between the two Hy-Line hybrids. In contrast, de Souza et al (2011) reported a generally higher carcass yield than that found in the present study both for Hy-Line White 36 (62%) and Hy-Line Brown (63%) layers.…”

“…In the present study, the advantage of the ISA Warren had two components, a higher BW and a higher carcass yield. The ISA Warren hens used in the present study even had a 2% points higher carcass yield than the Hy-Line Brown hens investigated by Rizzi et al (2007). In addition, the sausage meat yield in relation to carcass weight was generally higher in the present study.…”

“…These obvious disadvantages of the ISA Warren genotype concerning laying performance were at least partially counterbalanced when considering the meat yield. Rizzi et al (2007) also found a superior meat yield for Hy-Line Brown hybrids compared with Hy-Line White 36. In the present study, the advantage of the ISA Warren had two components, a higher BW and a higher carcass yield.…”

“…These so-called spent hens are culled and available for food purpose. However, in the past decades it has become difficult to market the carcasses worldwide (Lee et al, 1997;Rizzi et al, 2007;Chueachuaychoo et al, 2011), mainly because the cooking habits in industrialized countries have changed toward a more convenient, short preparation of meals. Thus, the traditional use as stewing hens has become much less common.…”

“…Among modern commercial layer genotypes, particularly the brown layers are heavier (Institut de Sélection Animale (ISA) B.V., 2011 and 2012) and thus likely also have a better meat yield per animal. Yet, thorough comparisons of different layer genotypes, which include the quantification of differences in meat amount and product quality issues, are scarce and sometimes outdated (Kondaiah and Panda, 1992;Rizzi et al, 2007;de Souza et al, 2011) considering the rapid breeding progress in poultry. The latter two studies both dealt with Hy-Line White 36 and Hy-Line Brown hens, but only de Souza et al (2011) studied a manufactured meat product.…”