Quality characterization of eggs from Romagnola hens, an Italian local breed

In the past years, consumers' concerns about sustainability and animal welfare have increased, strengthening the demand for eggs and meat produced through alternative and extensive farming methods. In addition, producers have also become increasingly interested in the recovery and exploitation of local breeds due to their adaptability to local environmental conditions, to valorize the biodiversity and to provide added value to typical products. Among the Italian local breeds, Romagnola has almost risked extinction and currently is reared in small-scale farms for eggs and meat production. The aim of this study was to characterize the egg quality traits of Romagnola chicken breed (RMG) compared to those obtained by a commercial hybrid (CONV). Ten laying hens of both Romagnola breed and Hy-Line Brown at 40 wk of age were housed in the same outdoor pen and fed the same commercial feed (ME 2,830 kcal/kg, CP 17.2%) for 10 wk. At 5 and 10 wk after housing, all the eggs laid in 4 consecutive days were collected and used for the determination of egg and eggshell characteristics as well as proximate composition and fatty acid profile of egg yolk. As expected, some important productive traits such as egg weight and production resulted higher in CONV chickens. However, eggs from RMG hens presented a higher yolk/egg ratio (31.1 vs. 24.9%; P < 0.01) as well as carotenoids (36.8 vs. 20.2 ppm; P < 0.01) and cholesterol content (12.8 vs. 11.7 mg/g of yolk; P < 0.01) than those laid by the conventional genotype. Moreover, yolks from RMG eggs were characterized by lower polyunsaturated fatty acid (PUFA) n-6 content (22.6 vs. 28.4%; P < 0.01) and PUFA n-6/n-3 ratio (11.3 vs. 13.5; P < 0.01) showing a healthier fatty acids profile than conventional eggs. These results highlighted several valuable egg quality traits of Romagnola chicken breed that might be exploited for the conservation and the development of this underutilized Italian pure breed.