Risk assessment of selection for restistant PrP alleles on milk production in Valle del Belice

Bottleneck detection in Sicilian goat breeds based on molecular information

Stima delle componenti della (co)varianza per il contenuto in cellule (CCS) in pecore di razza Valle del Belice

Survey of milk protein polymorphism in the "Rossa Siciliana" dairy cattle

“Rossa Siciliana” is a dairy cattle population traditionally linked to cheese production protein polymorphisms from 62 individual milk samples from 19 farms were analyzed by isoelectrofocusing. High variability was found at the CNS1S1, CSN2, CSN3, LGB and LALBA loci, while the CNS1S2 locus was monomorphic for the A allele. The casein haplotype frequencies and the occurrence of the linkage disequilibrium, taking into account the association among loci were investigated. The population was not in Hardy-Weinberg equilibrium (Chi-square=19.0, p-value=0.0407), probably due to genetic drift. Frequencies of the three allele detected at CSN1S1 locus were B (0.734), C (0.258) and D (0.008). high fre…

Trend in dairy sheep BLG genotype found with repeatability test-day model.

A total of 19.207 test-days, collected on 4 farms from 1999-2006 and belonging to 1109 Valle del Belice dairy sheep were analyzed with a repeatability model. After strict outlier analysis 17.747 records were retained. Animals were reared in an extensive system resulting in large environmental influences. However, significant genetic variation was detected in production traits (milk production mean=1336 stdg=93 g/d, fat+protein 167 stdg=12 g/d). Heritability was only 3% while the interaction year by month of test-day explained 27% of the variation. A protein and DNA analysis program was initiated in order to facilitate selection to maintain these flocks under these conditions. In total 427 a…

An experience in pedigree reconstruction based on likelihood methods using genetic markers

GoMilkSicily: an opportunity for transfer of knowledge

Relazione tra SNPs ai loci caseinici e tipizzazione lattoproteica nella capra Girgentana

La filogenesi della razza Girgentana ancora oggi rimane più o meno sconosciuta sebbene l’ipotesi più valida sembrerebbe quella che la ricollega alla capra Falconeri o Markor (Himalaya). La consistenza numerica della razza nell’ultimi anni ha subito una notevole contrazione, tanto da potersi annoverare tra le razze in via di estinzione. Il latte della capra Girgentana era utilizzato solo per il consumo diretto. Quando è entrato in vigore il regolamento che vietava la vendita del latte al dettaglio, il valore zoo-economico della razza Girgentana è diminuito notevolmente, contribuendo alla contrazione numerica della razza nell’ultimo ventennio. La rivalutazione della razza sarebbe di fondament…

Analyses of udder health in Valle del Belice dairy sheep using SCC

Intramammary infections (IMI) are a complex of inflammatory diseases of the mammary gland. Mastitis is one of the most frequent IMI affecting small dairy ruminants. Direct selection against clinical mastitis is difficult because mastitis in not widely recorded; therefore, somatic cell count (SCC) is promoted as selection criterion for mastitis resistance. A dataset containing 2,457 first- lactation Valle del Belice ewes from 14 flocks recorded from 1998 to 2003 was analysed. In total 116 sires with at least four daughters with a record were included in the pedigree file. Test-day IMI events were coded as a binary trait using a SCC cut-off value of 750,000 cells/ml. Analyses of risk factors …