Milk fatty acid composition is a parameter of great interest for evaluation of nutritional quality of milk. Stearoyl-CoA desaturase (SCD) is a key enzyme in mammary lipid metabolism because it is able to add a double bond in the cis ∆9-position in a large spectrum of medium- and long-chain fatty acids. A polymorphism with 2 alleles (A and V) in the fifth exon of the SCD gene has been reported. The effect of SCD genotype on individual milk fatty acid composition and on cis-9 unsaturated/saturated fatty acid ratios of 297 Holstein Italian Friesian cows was investigated in this paper. The SCD genotypes were determined by using a single strand conformation polymorphism method. Relative frequencies of SCD genotypes were 27, 60, and 13% for AA, AV, and VV, respectively. Milk of AA cows had a greater content of cis-9 C18:1 and total monounsatur- ated fatty acids and a higher C14:1/C14 ratio than did milk of VV cows. The relative contribution of SCD geno- type to variation of monounsaturated fatty acids, cis-9 C18:1, and cis-9 C14:1 was 5, 4, and 7.7%, respectively. No significant differences were detected between SCD genotypes in the milk content of cis-9, trans-11 C18:2. Results of the present work provide some indication of an association between SCD locus and the fatty acid profile in the examined sample of Italian Holsteins, thus suggesting a possible role of this gene in the genetic variation of milk nutritional properties.
|Autori:||MELE M; CONTE G; CASTIGLIONI B; CHESSA S; MACCIOTTA N.P.P; SERRA A; BUCCIONI A; PAGNACCO G; SECCHIARI P|
|Titolo:||Stearoyl-Coenzime a desaturase gene polymorphism and milk fatty acid composition in Italian holsteins|
|Anno del prodotto:||2007|
|Digital Object Identifier (DOI):||10.3168/jds.2006-617|
|Appare nelle tipologie:||1.1 Articolo in rivista|