Exploring the genetic variation between Sarda and Lacaune dairy sheep breeds by genome wide association study on economic traits

Abstract Text: Three Sarda (S) x Lacaune (L) back-cross generations comprising 2,373 ewes from 10 F1 sires and Sarda ewes were used to investigate breed origins of SNP effects on economic traits. Ewes were measured for milk (yields and contents), udder morphology, mastitis (SCS) and nematode resistance (FEC). Ewes and sires were genotyped with the Illumina Inc. OvineSNP50Beadchip. F1 phase and S or L haplotypes origins were determined from transmissions. A within-family linear regression was applied on the across years average of random performance deviations. Twenty-two among 52 significant locations at 1% CW were significant at 1% GW. QTLs affected milk yields (16), milk contents (17), udder morphology traits (10), SCS (3) and FEC (6). For milk yield traits, most of positive contrasts were in favor of L alleles. For the other traits, positive alleles were equally distributed between the two breeds.

Keywords:

Milk sheep

Health traits

QTL detection