Feeding Polyunsaturated Supplements to Grazing Dairy Cows Improve the Healthy Value of Milk Fatty Acids

Abstract

The objective of the experiment was to improve the healthy value of milk fatty acids (FA) by feeding sunflower oil (SO) or sunflower seed (SS) combined or not with fish oil (FO) to grazing dairy cows. Four Holstein cows (515 ± 80 kg liveweight) in late lactation (230 days postpartum) fitted with ruminal cannulae were allotted to a 4 × 4 Latin square design with factorial arrangement of treatments: SS = 1.9 kg dry matter (DM)/cow/d of SS; SO = 0.8 kg/cow/d of SO; SS-FO = SS + 0.24 kg/cow/d FO and SO-FO = SO + 0.24 kg/FO. Cows grazed a high quality pasture offered at 11 kg DM/cow/day. After the afternoon milking cows also received 5.6 kg DM/cow of corn silage and during each milking time cracked corn grain (1.3 kg DM/cow) mixed with a mineral-vitamin premix was fed. Oils and SS were introduced via ruminal cannulae and SS was fed roughly grounded. Milk yield tended (p < 0.07) to increase in SO treatments (9.9 vs 8.7 kg/d). Yields (kg/d) of fat corrected milk (FCM) (8.01 vs 6.37) and milk fat (0.27 vs 0.191) increased (p < 0.05) in SO diets and milk fat content was not affected. Milk protein concentration (40.5 vs 37.0 g/kg) and yield (0.397 vs 0.322 kg/d) were higher (p < 0.05) in SO without effects of FO or their interaction. Milk cholesterol content did not differ. The reduction in the atherogenic saturated FA of milk averaged 63% for C 12:0 , 51% for C 14:0 and 29% for C 16:0 . Atherogenicity index (AI) of milk was reduced particularly in SS-FO. Basal concentration of cis-9, trans-11 C 18:2 (CLA) in milk was 1.39 g/100g FA and increased (p < 0.05) by 144% across treatments without differences between SS or SO. Feeding FO increased (p < 0.05) milk contents of CLA (2.86 to 3.92 g/100g FA) and linolenic acid. Comparing SO or SS with or without FO showed no changes for neutral detergent fiber (NDF) and crude protein (CP) degradation of pasture. Polyunsaturated fatty acid (PUFA) fed to grazing dairy cows had a marked effect on milk FA profile putatively

Effect of Diet Supplementation with Combinations of Soybean and Linseed Oils on Milk Production and Fatty Acid Profile in Lactating Dairy Ewes

“…In the present trail, the lack of differences in DM at 7% of oil supply suggests the absence of any negative effect on ruminal digestion as was observed in dairy cows supplemented with polyunsaturated oils [24]. The results available on forage type or processing are scarce since most of the work in sheeps has been done using hay and the number of plant species involved is relatively low [44].…”

“…Neutral (NDF) [21] and acid detergent fiber (ADF) [22] were analyzed by the filter bag technique using an autoanalyzer for FA composition by gas-liquid chromatography (GLC) as described in [24].…”

Obtención de leche bovina reducida en grasa saturada y naturalmente enriquecida en ácido linoleico conjugado

“…Esto implicó un 36,75% de reducción de este parámetro asociado al riesgo cardiovascular de origen dietario. Resultados previos también indicaron disminuciones en el IA de la leche desde un valor basal de 1,88 a 0,5-0,8 en vacas lecheras que recibieron aceites de girasol y de pescado (Gagliostro, et al, 2017). Estos resultados contribuyen a evitar un exceso en el consumo de AGS no saludables y, potencialmente, a disminuir la presencia de marcadores sanguíneos asociados al riesgo cardiovascular.…”

“…El AV representó el 62,79% del total de los AG trans-C18:1 en la leche Control, resultado bajo en relación al 80,41% esperable y a lo reportado por Antonacci et al (2017). Dicha proporción disminuyó en la leche CLA a valores de 49,24%, mientras que en vacas en sistema pastoril suplementadas con aceites de soja y lino la proporción permaneció elevada (77 a 82%), con proporciones de trans-9 y trans-10 C18:1 de tan solo 11,5 y 28,9%, respectivamente (Antonacci, et al, 2017). En este trabajo, la proporción del trans-9 resultó baja (Control=10,47% y CLA=10,98%) pero la del trans-10 C18:1 experimentó un importante aumento en el tratamiento CLA (Control=26,74% y CLA=39,77).…”

“…Esto permite inferir que la actividad de la ∆-9 desaturasa mamaria (generadora del CLA a partir del AV) fue adecuada en las vacas de ambos lotes. Puesto que dicha relación fue mayor al valor promedio de 0,33% informado por otros autores para vacas suplementadas con AGPI (Antonacci, et al, 2017; Obtención de leche bovina reducida en grasa saturada y naturalmente.. . ISSN 1688-6593 · INNOTEC 2018, No.…”