Characterization of the Italian sheep breed Cornella Bianca

The Cornella Bianca (CO) is a native Italian ovine breed, belonging to the Apennines breed cluster. The last information about the state of this sheep population was from 1983, when about 2000-2500 animals where detected, mostly reared in the provinces of Bologna and Modena. A study, including population census, morfological, productive and genetic characterization of CO, has been recently carried out with the aim to characterize and preserve this autochthon breed. A total number of 750 animals, distributed in 16 different stocks, where detected, located in the provinces of Modena, Reggio Emilia, Bologna, Ferrara and Rovigo. Transhumance is already utilized by some shepherd. The presence of animals of another breed, Massese (MA), reared in the same herds with CO was very often detected. This last breed, specialized for milk production, has probably been utilized in the last decades to improve the milk productivity of CO. The study revealed that milk is the main production for CO, utilized for cheese-making. Linear measures of 49 animals were collected and these data show that the current CO population meets the breed standard. The evaluation of the genetic structure of CO was investigated using 15 microsatellites. The analyses where carried out on 31 CO individuals. Comparison with three other breeds belonging to the Apennines cluster, reared in neighbouring territories (35 Massese – MA, 29 Garfagnina Bianca – GA and 31 Zerasca – ZE) was studied. Observed and expected heterozygosity, mean number of alleles, F statistics, and Nei’s genetic standard distance (Ds) where calculated. The neighbour-joining tree topology was also obtained. A total of 140 alleles (from 7 to 16 alleles per microsatellite) were detected. Average heterozygosity was 0.693 in CO and ranged from 0.676 to 0.738 in the other three breeds. Gene differentiation coefficient (Fst) had an average value of 0.053. Standard Nei’s genetic distance values ranged from 0.132 between CO and MA and 0.271 between GA and ZE. In the Phylogenetic tree CO and MA form a separate cluster. These data confirm the introduction of MA rams in CO population. This study shows a strong decreasing in number of Cornella Bianca population in the last 25 years. Prosecution of the utilize of other breed for crossing could be very dangerous for the survival of this rare breed.