Identification of the association between gene polymorphisms and milk production traits in Sfakia sheep.

The aim of this study was to estimate the effect of variation in the fatty acid binding protein 4 gene () on milk production traits in Greek Sfakia sheep. Polymerase chain reaction - single-stranded conformational polymorphism (PCR-SSCP) analysis was used to genotype a total of 374 Sfakia ewes for two regions of located around exon 2-intron 2 (Region 1) and exon 3-intron 3 (Region 2). Each month, for a period of 6 months, milk samples were collected from the ewes to measure total milk yield, fat content, protein content, lactose content, non-fat solid content, pH, and somatic cell count (SCC). A general linear model was used to test the association between the variation observed in and milk production traits. Four gene variants (-) were found in Region 1 and two variants (-) were found in Region 2. In the first region, the genotype significantly affected ( ) non-fat solid levels, fat content, and SCC. The presence of the variant was significantly associated ( ) with decreased SCC, while the presence of was significantly associated with decreased milk yield ( ), increased non-fat solid content ( ), decreased fat content ( ), increased lactose content ( ), and increased pH ( ). In the second region, genotype had an effect ( ) on protein content and the presence of the variant was associated ( ) with increased protein content, decreased SCC, and lower pH. The results suggest an association between variation in ovine and milk production traits in Greek Sfakia sheep. Nevertheless, further analyses in independent sheep populations of increased size will strengthen these findings.