Dietary linseed oil with or without malate increases conjugated linoleic acid and oleic acid in milk fat and lipoprotein lipase and stearoyl-coenzyme A desaturase gene expression in mammary gland and milk somatic cells of lactating goats Academic Article uri icon

abstract

  • Supplementary dietary plant oils have the potential to alter milk fatty acid composition in ruminants as a result of changes in the amount and kind of fatty acid precursors. We hypothesized that linseed oil in combination with malate (a key propionate precursor in the rumen) would increase ∆9 unsaturated fatty acids and specific gene expression in somatic cells and mammary glands of lactating goats. Twelve lactating goats were used in a 3 × 3 Latin square design. Treatments included the basal diet (CON), the CON plus 4% linseed oil (LO), and the CON plus 4% linseed oil and 2% -malate (LOM). Relative to CON, the LO and LOM supplements increased the daily intake of palmitic (16:0), stearic (18:0), oleic (18:1-9), linoleic (18:2-6), α-linolenic (18:3-3), and γ-linolenic acids (18:2-6); α-linolenic acid intake was increased over 9-fold, from 6.77 to over 51 g/d ( < 0.02). The LO and LOM supplements increased daily milk yield, milk fat yield, and milk fat percentage ( < 0.05). The LOM supplement also increased milk lactose percentage and daily yield ( = 0.03). Both the LO and LOM supplements increased plasma glucose and total cholesterol and decreased plasma β-hydroxbutyrate concentrations ( = 0.03). The LO and LOM supplements increased concentrations of stearic acid; -vaccenic acid (TVA; 18:1-11); -9, -11 CLA; -10 -12 CLA; and α-linolenic acid in rumen fluid and increased the concentrations of oleic acid; TVA; -9, -11 CLA; -10, -12 CLA; and α-linolenic acid in plasma lipids and milk fat ( < 0.05). Conversely, the LO and LOM supplements decreased short- and medium-chain SFA, including lauric (12:0), myristic (14:0), and palmitic acids, in plasma and milk fat ( < 0.05). Relative mRNA levels for and () gene expression were increased in somatic cells and mammary gland tissue by LO and LOM ( < 0.05). We conclude that the higher intake and ruminal production of stearic acid promoted SCD gene expression in somatic cells and mammary tissue. Furthermore, milk somatic cells are a suitable substitute for documenting treatment effects of dietary oils on gene expression in goat mammary tissue.

author list (cited authors)

  • Li, X. Z., Choi, S. H., Yan, C. G., Shin, J. S., & Smith, S. B.

citation count

  • 1

publication date

  • August 2016