## 4 Discussion
[31] have confirmed the QTL regions associated with mastitis resistance in sheep of that breed. The Greek breed most frequently recorded in the farms was the Chios. These animals are considered highly susceptible to mastitis. For example, [PERSON] et al. [32] have reported that _Staphylococcus chromogenes_ can survive in the mammary glands of Chios-breed ewes during the dry-period and cause subclinical infection after the subsequent lambing; in another study, [PERSON] et al. [33] have reported that the prevalence of subclinical mastitis in flocks with Chios-breed animals was 32%, higher than the national average of 26% [33]. Although genomic regions associated with specific mastitis traits in Chios-breed sheep have been identified [34], unfortunately, in Greece, no genetic improvement programmes have been developed for resistance to mastitis despite the significance of the breed for the sheep population of the country. This was reflected in the fact that there was a high proportion of farms with Chios-breed animals that had increased somatic cell counts in the bulk-tank milk; in fact, the results indicated that farms with Chios-breed animals had higher odds for increased SCC. Possible reasons for the increased susceptibility of the breed could be the bad udder conformation in animals of this breed, which adversely affects correct milking and can predispose animals to mammary infections [2]. In Latka- and Sarda-breed animals, a positive association was found between SCC and udder conformation [35; 36], suggesting that udders with what is perceived to be a good shape would be less affected by subclinical mastitis. Moreover, in Chios-breed animals, a peri-parturient immunosuppression associated with macrophage and neutrophil function has been found and can contribute to the development of mastitis [37]. In contrast, there was a low proportion of farms with animals of the Mytilini-breed that had increased SCC in bulk-tank milk. Future studies could be based on breed as a potential model for mastitis resistance among Greek breeds. Unfortunately, however, the breed is native to the island of Lesvos, where bluetongue is endemic [38] and, consequently, the Ministry of Agriculture has imposed a total ban on animal movements outside that island. In goats, there is significantly less work regarding potential resistance to mastitis. Some work has been carried out in Alpine-breed [11] or Saanen-breed [39] animals. Again, in the Greek breeds, no efforts toward relevant genetic improvement have been made and this was reflected in farms with the local Indigenous Greek breed (_Capra prisca_) being at higher odds of having increased SCC in bulk-tank milk. However, no systematic efforts have been carried out as in sheep for resistance to the infection. However, apart from breed, other factors were also found to be important for increased SCC, specifically the use of hand-milking for sheep and the application of semi-extensive or extensive management systems for goats (in which most often hand-milking is used). Similar findings have been reported in Spain by [PERSON] et al. [40], who studied four breeds (Assaf, Awassi, Churra and Castelana) and found that SCC in hand-milked flocks were higher than in machine-milked ones. In hand-milked ewes, staphylococci from the hands of milkers can be transmitted to the teats of ewes [41]. Likely as a consequence of that, hand-milking has been found to result in increased bacterial colonisation within the teat duct [42]. These bacteria can lead to mastitis, when the local defences of the teat are impaired [43,44], during which SCC increases, and reflect higher SCC in the bulk-tank milk of the farm. In contrast, in goats, no such differences were reported in a study of two breeds (Alpine and Nubian) and SCC did not differ between machine- or hand-milked herds [45]. In goat farms, we found that the application of extensive or semi-extensive management systems can be significant factors for increased SCC.