Li, YunhaiZhou, HuitongCheng, LongZhao, JennyHickford, Jonathan2021-03-022020-11-032020-11-032020-09-030003-9438OQ4KP (isidoc)33178884 (pubmed)https://hdl.handle.net/10182/13495Gene markers have become useful tools for improving animal genetics and breeding since they improve the accuracy of selection for superior breeding stock. In this study, the stearoyl-CoA desaturase (Δ-9-desaturase) gene (SCD) was investigated in New Zealand pasture-grazed Holstein-Friesian × Jersey cows. Three nucleotide substitutions were identified in exon 5 of the gene (c.702A/G, c.762T/C and c.878C/T), and a single nucleotide substitution was identified in intron 5 (c.880C105A/G). The c.878C/T substitution would, if expressed, result in the amino acid substitution p.A293V. Four nucleotide substitutions (c.∗1783A/G, c.∗1883C/T, c.∗1984G/A and c.∗2066T/C/G) were identified in the 30-untranslated region (3′-UTR), and these resulted in three nucleotide sequence variants (named a, b and c). The sequence that would encode valine (V) at position 293 of SCD was linked to 3′-UTR variant a, and the sequence that would encode alanine (A) was linked to variants b and c. The frequency of the genotypes was as follows: VV (equivalent to aa: 15.1 %), VA (equivalent to ab C ac: 50.0 %) and AA (equivalent to bb C cc C bc: 34.9 %). The cows with the V variant produced less C10:1, C12:1 and C14:1 fatty acid (FA) but more C10:0, C11:0, C14:0, C16:1 and C18:2 FA than the A variant cows (P < 0.001). Effects of c.∗1783A/G and c.∗2066T/C/G on milk fat composition were also found for the AA cows. The presence of c was associated with decreased levels of C16:1 (P < 0.001), C17:1 (P D 0.001), C18:2 cis-9, trans-13 (P D 0.045), C18:2 cis-9, trans-12 (P D 0:018) FA and C16:1 FA index (P < 0.001). The presence of b was associated with increased levels of C13:0 iso FAs (P < 0.001), monounsaturated FA (MUFA; P D 0.002) and C12:1 (P < 0.001).pp.355-366Electronic-eCollectionen© Author(s) 2020.genelactatedairy cattleStearoyl-CoA desaturase (SCD)fatty acidsmilkJournal Article10.5194/aab-63-355-2020ANZSRC::0702 Animal ProductionANZSRC::070202 Animal Growth and DevelopmentANZSRC::070201 Animal BreedingANZSRC::100104 Genetically Modified Animals2363-9822ANZSRC::3003 Animal productionhttps://creativecommons.org/licenses/by/4.0/Attribution