Quality of organic eggs of hybrid and Italian breed hens.
The quality of eggs laid by 2 hybrid and 2 Italian dual-purpose genotypes of hens reared under organic farming system was studied. Hens belonging to Hy-Line Brown (brown eggshell, HLB), Hy-Line White (white eggshell, HLW), Ermellinata di Rovigo (brown eggshell, E), and Robusta maculata (brown eggshell, R) genotypes were reared from 24 to 43 wk of age. The trial was carried out from July to December, with environmental temperature ranging from 25°C (±5°C, summer) to 13°C (±7°C, autumn). The HLB eggs were heavier (P < 0.01) than HLW (62.9 vs. 60.4 g), and R eggs were heavier (P < 0.01) than E (56.5 vs. 54.4 g). The albumen weight differed (P < 0.01) among HLB, HLW, R, and E (40.7, 38.3, 32.7, 34.1 g, respectively). The E and R yolk weights were similar (16.2 g) and higher (P < 0.01) than hybrids; HLW yolk was higher (P < 0.05) than HLB (15.8 vs. 15.5 g). The HLB showed the highest (P < 0.01, 6.74 g) shell weight and E had the lowest (P < 0.01; 5.43 g). The yolk cholesterol content was higher (P < 0.01) in the Italian eggs than in the hybrids (258 vs. 219 mg/yolk). The HLB yolk had the lowest (P < 0.01) saturated fatty acids (33.8 vs. 34.9%), and R yolks showed the lowest (P < 0.01) monounsaturated fatty acids (36.3 vs. 38.0%) and the highest (P < 0.01) polyunsaturated fatty acids (28.7 vs. 27.4%) than the other groups. The HLW yolk showed the highest (P < 0.01) n-6/n-3 ratio (13.7) in comparison to the other 3 groups (12.8). During 21 d of storage (at 21°C and 62% RH), the E eggs showed the lowest (P < 0.01) quality (albumen height, 4.93 vs. 5.56 mm; Haugh units, 71 vs. 74). A sensory profile of boiled eggs showed differences (P < 0.05) in odor and flavor sensations and in certain yolk and albumen texture properties according to genotype. The quality of organic eggs from different genotypes differs in relation to the strain but also the interaction with the environmental conditions has to be considered.
Department of Animal Science, University of Padua, Viale dell'Università, 16 Agripolis, 35020 Legnaro (Padua), Italy. chiara.rizzi@unipd.it
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Marangon
D000821:Animal Feed / Q000032:analysis; D000822:Animal Husbandry / Q000379:methods*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000235:genetics*; D004032:Diet / Q000662:veterinary; D004531:Eggs / Q000592:standards*; D005260:Female; D005838:Genotype; D006824:Hybridization, Genetic; D006863:Hydrogen-Ion Concentration