title: Milk fatty acid profile is modulated by DGAT1 and SCD1 genotypes in dairy cattle on pasture and strategic supplementation.
abstract: Milk fat composition is important to consumer health. During the last decade, some fatty acids (FA) have received attention because of their functional and beneficial effects on human health. The milk FA profile is affected by both diet and genetics. Differences in milk fat composition are based on biochemical pathways, and candidate genes have been proposed to explain FA profile variation. Here, the association between DGAT1 K232A, SCD1 A293V, and LEPR T945M markers with milk fat composition in southern Chile was evaluated. We selected five herds of Holstein-Friesian, Jersey, Frisón Negro, Montbeliarde, and Overo Colorado cows (pasture-grazed) that received strategic supplementation with concentrates and conserved forages. We genotyped the SNPs and calculated allele frequencies and Hardy-Weinberg equilibrium. Milk fat composition was determined for individual milk samples over a year, and associations between genotypes and milk composition were studied. The most frequent variants for DGAT1, SCD1, and LEPR polymorphisms were GC/GC, C, and C, respectively. The DGAT1 GC/GC allele was associated with lower milk fat and protein content, lower saturated fatty acid levels, and higher polyunsaturated FA (PUFA), n-3 and n-6 FA, and a linolenic acid to cholesterolemic FA ratios, which implied a healthier FA profile. The SCD1 CC genotype was associated with a low cholesterolemic FA content, a high ratio of linolenic acid to cholesterolemic FA, and lower conjugated-linolenic acid and PUFA content. These results suggest the possible modulation of milk fat profiles, using specific genotypes, to improve the nutritional quality of dairy products.
authors.affiliation: Instituto de Investigaciones Agropecuarias INIA Remehue, Osorno, Chile.
authors.forename: A M
authors.initials: AM
authors.lastname: Carvajal
authors.affiliation: Instituto de Investigaciones Agropecuarias INIA Remehue, Osorno, Chile.
authors.forename: P
authors.initials: P
authors.lastname: Huircan
authors.affiliation: Programa de Magister en Producción Animal, Universidad Austral de Chile, Valdivia, Chile.|Ministère de l'Agriculture des Ressources Naturelles et du Développement Rural, Direction Départementale Agricole de l'Artibonite, Gonaives, Haiti.
authors.forename: J M
authors.initials: JM
authors.lastname: Dezamour
authors.affiliation: Instituto de Investigaciones Agropecuarias INIA Remehue, Osorno, Chile.
authors.forename: I
authors.initials: I
authors.lastname: Subiabre
authors.affiliation: Centro de Estudios Científicos, Valdivia, Chile.
authors.forename: B
authors.initials: B
authors.lastname: Kerr
authors.affiliation: Instituto de Investigaciones Agropecuarias INIA Remehue, Osorno, Chile.
authors.forename: R
authors.initials: R
authors.lastname: Morales
authors.affiliation: Instituto de Investigaciones Agropecuarias INIA Carillanca, Vilcun, Chile.
authors.forename: E M
authors.initials: EM
authors.lastname: Ungerfeld
mesh_terms: D000483:Alleles; D000818:Animals; D002417:Cattle; D003611:Dairy Products; D051048:Diacylglycerol O-Acyltransferase / Q000235:genetics*; D019587:Dietary Supplements; D044943:Fatty Acid Desaturases / Q000235:genetics*; D005227:Fatty Acids / Q000235:genetics* / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated; D005260:Female; D056726:Genetic Association Studies; D005838:Genotype; D008892:Milk; D020641:Polymorphism, Single Nucleotide; D054411:Receptors, Leptin / Q000235:genetics; D013230:Stearoyl-CoA Desaturase; D059467:Transcriptome / Q000235:genetics
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D054411:Receptors, Leptin; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; C029627:delta-9 fatty acid desaturase; D051048:Diacylglycerol O-Acyltransferase