Effect of olive oil in dairy cow diets on the fatty acid profile and sensory characteristics of cheese

Simple SummaryThe objective of this study was to evaluate the effects of supplementation of dairy cows’ diets with different fatty acid (FA) sources on milk production, milk composition, milk fatty acid profile, and physicochemical and sensory characteristics of ice cream. Supplementation (3% dry matter (DM)) of diets with soybean oil (SO) and fish oil (FO) did not have detrimental effects on milk production, milk composition, or ice cream physicochemical and sensory characteristics. From a human standpoint, SO and FO improved the FA profile of milk.AbstractThe objective of this study was to evaluate the effects of supplementation of dairy cows with different fatty acid sources (soybean oil (SO) and fish oil (FO)) on milk production, milk composition, milk fatty acid profile, and physicochemical and sensory characteristics of ice cream. During 63 days, fifteen Holstein cows averaging 198 ± 35 days in milk were assigned to three groups: control diet with no added lipid (n = 5 cows); and supplemented diets with SO (n = 5 cows; unrefined SO; 30 g/kg DM) or FO (n = 5 cows; FO from unrefined salmon oil; 30 g/kg DM). Milk production, milk fat, and milk protein were not affected by treatments. Saturated fatty acids in milk fat were decreased with SO and FO compared with control. C18:2 cis-9, cis-12 was increased with SO whereas C18:2 cis-9, trans-11, C20:3n-3, C20:3n-6, C20:5n-3, and C22:6n-3 were the highest with FO. Draw temperature and firmness were higher in SO compared to control and FO ice creams. Melting resistance was higher in FO compared with control and SO ice creams. Supplementation of cow diets with SO and FO did not have detrimental effects on milk production, or ice cream physicochemical and sensory characteristics.

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This study analyzed effects of vegetable oils fed to dairy cows on abundance of genes related to lipid metabolism in milk somatic cells (MSC). During 63 days, 15 cows were allocated to 3 treatments: a control diet with no added lipid the same diet supplemented with olive oil (OO, 30 g/kg DM) or hydrogenated vegetable oil (HVO, 30 g/kg DM). On days 21, 42 and 63, MSC were obtained from all cows. Relative abundance of genes involved in lipid metabolism in MSC from cows fed control on days 42 and 63 was compared with relative abundance at day 21 to evaluate fold-changes. Those genes without changes over the time were selected to analyze effects of OO and HVO. Compared with control, on day 42, PLIN2 and THRSP were upregulated by OO. Compared with control, on day 21, HVO up regulated ACACA, down regulated FABP3, and on day 63 THRSP and FABP4 were down regulated. Dietary oil supplementation (3% DM) had a modest nutrigenomic effect on different biological functions such as acetate and FA activation and intra-cellular transport, lipid droplet formation, and transcription regulation in MSC.

In humid temperate regions, forage turnip (Brassica rapa ssp. rapa) and forage rape (Brassica napus ssp. biennis) are common fodder crops used for dairy cattle during the summer season. However, there is little scientific information regarding the use of brassicas and their effect on the fatty acid (FA) profile in blood, milk, and milk products. The aim of this study was to evaluate the effect of forage brassica supplementation in dairy cows on the FA profile of blood plasma, milk, and cheese, and on the sensory characteristics of Chanco and Ricotta cheeses. Twelve multiparous dairy cows (Holstein Friesian) were housed and submitted to a 3 × 3 replicated (n = 3) Latin square design with 3 treatments (control, turnip, or rape) in 3 periods of 21 d each (14 d of diet adaptation and 7 d of measurements). The control diet consisted of 16.20 kg of grass silage (Lolium perenne), 2.25 kg of soybean bran, and 2.25 kg of commercial concentrate, all on a dry matter (DM) basis. In the treatments with forage brassicas, 24.15% of the total DM was replaced by turnip or rape; thus, they consisted of 12.25 kg of silage, 2.25 kg of soybean bran, 1.2 kg of concentrate, and 5 kg of turnip or rape (DM basis). A principal components analysis was performed on the results of the cheese sensory evaluation. Supplementation with turnip or rape modified the profile of FA in blood plasma and milk, increasing the saturated fraction, mainly short-and medium-chain FA, and decreasing the mono-and polyunsaturated FA. In the sensory evaluation, diet did not affect any of the 18 attributes evaluated. However, in the principal components analysis, cheeses made with milk from animals fed turnip and rape were differentiated by increased odor, flavor, spiciness, bitterness, and acidity. Overall, brassicas can be used as an alternative forage source with no negative effects on sensory characteristics of cheeses.