CONSERVATION AND VALORIZATION OF ITALIAN CHICKEN BREEDS

My research activities have been carried out within the CoVAL Project, a research program which examines the conservation of four Italian avian breeds (two chicken and two turkey breeds). The research has planned the development of several activities aiming the acquisition of a complete characterization of the breeds and the organization of a conservation program according FAO guidelines. Two conservation strategies have been considered: the primary in situ – that enables the conservation of the birds in their original background- and the complementary ex situ in vitro – with the aim to implement a semen cryobank. The project, funded by Regione Lombardia, lasted forty-two months, from December 2011 to June 2015. The results reported in this thesis only concern the two chicken breeds, in particular Milanino breed, that presents high meat-production potentialities. Data have been systematically gathered studying various generations of birds. The phenotypic characterization has highlighted the reproductive performance (fertility, hatchability) typical of each breed. Furthermore, variability of these traits has been studied depending on factors such as age, family, weight and storage period of eggs: prospects of selections and improvement have been pointed out. The results of zootechnical trials have provided a procedural guideline for outdoor extensive farming system specific for the chicken breeds. The guideline provides information about rearing density and dietary protein level during the growing period. In Milanino breed the slaughter performance and the quality of meat have been studied at two different age of slaughter (150 and 180 days old chickens). Milanino chickens have disclosed a high slaughter performance and the analysis of their meat has pointed out a high protein and a small lipid percentage, which suggest a high nutritional value. In general, the results achieved prove the potentiality of Milanino breed for meat production The ex situ in vitro strategy has been devoted to the identification of a reference procedure for the cryopreservation of chicken semen according FAO guidelines. Several trials have been carried out to improve cryopreservation success; in short, several gradients of cooling rates and the combined effect of permeant and non-permeant cryoprotectants have been studied. The final reference procedure involves the use of a very high cooling gradient and the innovative combination between a permeating cryoprotectant, dimethylacetamide, and a non-permeating one, trehalose. The cryopreservation reference procedure has been used for the conservation of the semen of Milanino and Mericanel della Brianza breeds, pointing out a lower cell damage post thawing in Milanino breed.