Effect of postruminal supply of linseed oil in dairy cows: 2. Milk fatty acid profile and oxidative stability.

Autor: Rico DE; Département des Sciences Animales, Université Laval, Québec, Québec, Canada G1V 0A6., Gervais R; Département des Sciences Animales, Université Laval, Québec, Québec, Canada G1V 0A6., Peňa-Cotrino SM; Département des Sciences Animales, Université Laval, Québec, Québec, Canada G1V 0A6., Lebeuf Y; Département des Sciences Animales, Université Laval, Québec, Québec, Canada G1V 0A6., Chouinard PY; Département des Sciences Animales, Université Laval, Québec, Québec, Canada G1V 0A6.
Jazyk: angličtina
Zdroj: The Journal of dairy research [J Dairy Res] 2023 May; Vol. 90 (2), pp. 124-131. Date of Electronic Publication: 2023 May 08.
DOI: 10.1017/S0022029923000262
Abstrakt: Our objective was to study the effect of increasing postruminal supply of linseed oil (L-oil), as a source of cis -9, cis -12, cis -15 18:3, on milk fatty acid profile and to assess the resulting impact on the development of volatile degradation products during the storage of homogenized milk. Five Holstein dairy cows fitted with a rumen cannula were randomly distributed in a 5 × 5 Latin square design. Abomasal infusion of L-oil was performed at the rate of 0, 75, 150, 300, and 600 ml/d during periods of 14 d. The concentration of cis -9, cis -12, cis -15 18:3 in milk fat increased linearly with L-oil dose. Concentrations of primary (conjugated diene and triene hydroperoxides) and secondary oxidation products (1-octen-3-one, propanal, hexanal, trans -2 + cis -3-hexenals, cis -4-heptenal, trans -2, cis -6-nonadienal trans -2, trans -4-nonadienal) increased during 11 d of storage at 4°C of homogenized milk under fluorescent light. The magnitude of the increase (difference between final and initial measurements) was linearly greater for all nine lipid oxidation products evaluated in response to increasing level of infusion. Results of the current experiment have shown that milk enriched in cis -9, cis -12, cis -15 18:3 via postruminal supply of L-oil is highly prone to oxidative degradation. This low oxidative stability, exposed under controlled experimental conditions, would represent a major obstacle to those who aim to market milk enriched in polyunsaturated fatty acids.
Databáze: MEDLINE