Does the incidence of egg yolk influence the meat quality and fatty acid profile of broilers of two chicken genotypes?

The present experiment studied the effects of egg composition (egg yolk content; Y) of two different chicken genotypes (selected by computed tomography; CT) on hatched chick growth performance, slaughter traits, and meat quality. Three thousand five hundred eggs per genotype were scanned by CT. Then, for each genotype, eggs were selected according to their Y content: low (21.0 ± 0.88 - 350 eggs), medium (24.5 ± 0.15- 350 eggs) and high (28.3 ± 0.98 - 350 eggs). The remaining eggs were excluded from the study. At 11 weeks of age, 15 chickens per group were slaughtered, carcasses were dissected and breast and legs were excised and dedicated to meat quality evaluations. Many parameters were influenced in the meat-type (EE) chickens, including slaughter, breast and leg weights, and abdominal fat content, whereas only the breast incidence on slaughter weight was affected in Tetra-H hybrid. In neither genotype were the meat traits affected by Y content. Two exceptions were represented by leg thawing loss, higher in low Y group compared to medium and high Y group, and by tibia length, longer in high Y content group than in the medium one, both for EE chickens. Similar findings were observed for the meat fatty acid (FA) profile, as only some single FA were influenced by Y content, however, apparently without a specific physiological meaning. The present work demonstrated that the Y content, measured by CT, allowed to select high-quality meat-type animals characterised by the best productive performances in terms of growth rate, live weight, slaughter weight, breast and thigh weights, and with lower abdominal fat content. These findings would bring positive advantages to hatcheries in terms of chick quality and also to farmers in terms of economic revenues: They would rear robust animals that would guarantee a higher probability of survival in the first rearing period and would be characterised by a high slaughter weight at the end of the productive cycle.