| Título: | Milk fatty acid profile from cows fed with mixed rations and different access time to pasture land during early lactation |
| Autores: | BARCA, JOAQUIN, Autor ; CARRIQUIRY, MARIANA, Autor ; LAURA OLAZÁBAL, Autor ; FAJARDO, MAITE, Autor ; PABLO CHILIBROSTE, Autor ; MEIKLE, ANA, Autor |
| Tipo de documento: | documento electrónico |
| Fecha de publicación: | 2018 |
| ISBN/ISSN/DL: | 69221 |
| Dimensiones: | 10 p. |
| Nota general: | En: Journal of Animal Physiology and Animal Nutrition, 2018, 102(3), pp.620-629. doi: 10.1111/jpn.12826 |
| Langues: | Inglés |
| Clasificación: | |
| Resumen: |
Milk fatty acid (FA) profiles were determined in Holstein cows (n = 27) fed total mixed rations (TMR) ad libitum (G0) or diet composed by TMR (50% dry matter [DM] offered) plus grazing of pasture with 6 hr of access time to paddock in one session (G1) or 9 hr in two sessions (G2) at 45 days in milk (DIM). Moreover, milk FA was determined at 65 DIM when G0 cows turned out to G1 diet without adaptation period (Post-G0),G1 remained as controls. Milk FA was quantified using gas chromatography and mass
spectrometry. Preformed FA at 45 DIM was greater (+27%) for G2 than G0 cows (p < .05). Stearic acid (C18:0) was 30% greater for G2 cows (p < .05). De novo FA was lowest for G2 cows (p < .05). Conjugated linoleic acid (CLA) did not differ (p < .12), while vaccenic acid (C18:1trans) was twofold greater for grazing treatments (p < .01). Linolenic acid [C18:3(n-3)] was greatest for G2 and lowest for G0 cows (p < .01). Omega 6 FA was greater for G0 than grazing cows, mainly due to linoleic acid [18:2cis(n-6); p < .05]. These results determined that n-6/n-3 ratio was almost threefold greater for G0 than grazing cows (p < .001). When diet of G0 cows changed to include pasture (Post-G0), preformed FA increased (p < .05), explained mainly by the increase (p < .05) of stearic (C18:0) and C18:1trans, while de novo FA tended to decrease (p < .1). Moreover, the amount of CLA and C18:3(n-3) tended to increase (p < .1) in Post-G0 cows. Offering 50% of dietary DM from pasture modified milk FA profile in early lactation potentially beneficial for human health. When TMR-fed cows were turned out to 50% pasture, milk FA profile reflected dietary change without need of an adaptation period. |
| dc.identifier.doi : | 10.1111/jpn.12826 |
| Creative Commons : | CC BY-NC-ND |
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