Primers for PGK1, SDHA and G6PD were based on previous publications [5, 7] . The other primers were designed using Primer3 software [32] by aligning ovine sequences available in GenBank with bovine and human homologous genes. Primers were selected to produce amplicons spanning two exons and their specificity was tested using ovine pooled cDNA and genomic DNA in preliminary PCR assays. The PCR products were subsequently run on 2% agarose gel to check for size specificity and, eventually, sequenced. Table 3 summarises primers information including sequences, product size, putative exon position, estimated size of the amplicon, efficiency of RT-PCR (E) and correlation coefficients (R 2 ). 