Phenotypic characterisation of Italian local chicken populations

In recent years the interest in saving biodiversity and local population is growing and becoming a matter of grate importance. The aim of this study was to determine the growing performance and to provide the phenotypic characterisation of four Italian chicken populations of three Italian purebred: Siciliana (S), Ancona (A) and Livorno in two plumage varieties, white (WL) and black (BL). A total of 77 black Livorno (40 males and 37 females), 30 white Livorno (10 males and 20 females), 47 Ancona (22 males and 25 females) and 44 Siciliana (22 males and 22 females) were evaluated. The birds were raised from day 1 to day 28 in controlled environment and feed ad libitum with a starter commercial diet (23% CP and 11.80 MJ/kg ME ), thereafter transferred in outdoor pens (1,5 m2/bird) and, from 56 day of age, the starter diet was gradually replaced with a low protein diet (13% CP and 12.10 MJ/kg ME commercial mixed grain diet). Starting from day one the birds were weighted at 14 days interval up to 16 weeks of age, then at 35 days interval up to 31 weeks of age. During the last data recording session, physical measurements of the young adults (body weight and length, chest circumference, shank length, circumference and diameter, wing span and spur length) were taken according to the 2012 FAO guidelines for chickens phenotypic characterization. The growth curves for males and females of each population were estimated by the Gompertz function and the goodness-of-fit of the model was assessed using R2adj. The physical measurements were analyzed by ANOVA. The R2adj calculated for the S, A, WL and BL young hens was 0.967, 0.965, 0.977 and 0.896 respectively, and for the S, A WL and BL cockerels was 0.967, 0.,967, 0.978 and 0.921, respectively. The physical characterisation confirmed that these breeds are slow-growing chickens, with a characteristic sexual dimorphism. Significant differences among the four populations (P<0,001), confirming S to be the lowest in body weight (male: 1766 g; female:1367 g) as well as in most of the other recorded parameters. WL, BL and A resulted similar for body weight (range for males: 2137-2416 g; range for female:1648-1685 g). WL was the widest for chest circumference while BL resulted the bigger in body length and wing span.