Broiler carcass and meat quality as affected by egg yolk content determined by means of Computer Tomography

摘要

Computer tomography (CT) was used to select eggs with Low (L; 21.0±0.88 %), Medium (M; 24.5±0.1 5 %) and High (H; 28.3±0.98 %) yolk content with the purpose to check the effectiveness of this egg selection technique in improving broiler carcass and meat traits of two genotypes: dual purpose, LL (Tetra-H hybrid; Babolna TETRA Kft.) and meat type, EE (hybrid of Plymouth rock breed origin). All chicks were slaughtered at 11 wk of age. Carcass yield, leg components and rheological traits, and breast main fatty acid (FA) groups were analyzed. All traits of LL birds weren't influenced by the egg yolk content. On the contrary, it significantly affected broiler carcass traits of EE genotype: birds belonging to L group, compared to H and M groups, showed higher slaughter weight (SW; 3.6 vs 3.4 vs 3.3 kg; P<0.05) and grill-ready weight (2.4 vs 2.3 vs 2.2 kg; P<0.05), respectively. The abdominal fat incidence significantly increased as yolk content increased (0.77 vs 1.00 vs 1.33 %; P<0.05). Birds belonging to the L group exhibited the highest leg weight (840 vs 754 vs 793 g for L, M and H groups, respectively; P<0.05) and thawing losses (2.22 vs 1.46 vs 1.67 % for L, M and H groups, respectively; P<0.001). No effect of yolk content on main FA groups was found in the 2 genotypes. EE males exhibited best SW, carcass yield, WHC, tibia strength, PUFA contents and lower dissectible fat of legs than EE females (P<0.05). On LL males only SW and tibia strength were higher than on females (P<0.01). Bird selection according to the yolk content was effective only on EE genotype: chickens whose belonged to eggs with L yolk content were heavier and leaner but were characterized by a reduced meat WHC.