Effects of Feeding Combinations of Soybean and Linseed Oils on Productive Performance and Milk Fatty Acid Profile in Grazing Dairy Cows

Abstract

Thirty-six grazing dairy cows were used to determine the effect of combinations of soybean (SO), and linseed (LO) oils on milk production, composition and milk fatty acid (FA) profile. Treatments were a basal control diet (56% pasture, 44% concentrate) or the control diet supplemented with oils at 4% of estimated total dry matter (DM) intake. Oils were manually mixed to the concentrate in pure forms (SO100 or LO100) or in blends (%w/w) at SO75 -LO25, SO50 -LO50 and SO25 -LO75. Concentrate and oils were thoroughly consumed. Pasture intake (kg DM/cow•day) was 9.27 in control and decreased (p < 0.05) in SO25 -LO75 (8.09) and LO100 (8.98). Total DM intake (kg/cow•day) in control (16.47) increased (p < 0.05) to 17.04 in SO100 and 17.20 in SO75. Yield of fat corrected milk (4% FCM) averaged 20.73 kg in control resulting higher in SO75 (23.73 kg). Milk fat content (g/100g) in control averaged 3.40 and decreased to 2.79 in SO50-LO50 and to 3.06 in SO25 -LO75 treatments. Milk protein content was not affected and milk protein yield increased in SO100 (11%) and SO75 -LO25 (21%) . Results obtained confirmed a great milk fat plasticity in response to PUFA feeding in grazing dairy cows which constitutes a very effective and easy tool in order to improve the healthy value of milk with a potential benefit to the consumer's health. A net or conclusive response pattern over parameters that improve the healthy value of milk to soybean and linseed oils and their blends was not clearly detected. Taken together, the results suggest some advantage for the SO75:LO25 blend considering the relative costs of both oils, the positive effects on milk, fat and protein yields, the lower hypercholesterolemic FA content of milk and the increase in VA and RA content while maintaining a healthy n − 6/n − 3 ratio and very low levels of the detrimental trans-9 C18:1 and trans-10 C18:1 FA.

Improving Concentration of Healthy Fatty Acids in Milk, Cheese and Yogurt by Adding a Blend of Soybean and Fish Oils to the Ration of Confined Dairy Cows

“…The low content of trans-10 C 18:1 in Mod-Milk is also compatible with the low decrease in milk fat concentration observed (Table 3) and with the lowest reduction of C 12:0 to C 16:0 respect to our previous trial [20]. It was shown that the decrease in milk fat content is negatively correlated to trans-10 C 18:1 levels [32] [53]. A high trans-10 C 18:1 concentration, or its related metabolites like trans-10, cis-12C 18:2 in milk, has been associated with dysfunctions in lipoprotein lipase (LPL) and stearoyl CoA desaturase (SCD) enzymes involved in milk fat uptake (LPL) and synthesis explaining the decrease in the fatty content of milk [54].…”

Improving the Quality of Milk Fatty Acid in Dairy Cows Supplemented with Soybean Oil and DHA-Micro Algae in a Confined Production System

“…This proportion resulted even lower in L-TMR milk decreasing up to 41% ( Table 1). When grazing dairy cows were supplemented with soybean and linseed oils contribution of VA remained high (77% to 82%) whereas that of trans-9 and trans-10 C 18:1 were only 11.5% and 28.9% respectively [43]. In the present work, the proportion of trans-9 was low in both treatments (13.14% to 8.65%) but that of trans-10C 18:1 showed a significant increase in L-TMR treatment (50.32%) compared to C-TMR (25.14%).…”

“…In our trial, the increase in VA was somehow moderate and should be strengthened. In C-TMR milk, VA represented about 61.7% of the total trans-C 18:1 , a value that resulted low considering the 80.41% proportion observed in milk from cows fed pasture based diets [43]. This proportion resulted even lower in L-TMR milk decreasing up to 41% ( Table 1).…”

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

“…In our trial, supplementation with the 50% SO-LO blend showed the greatest persistence in milk RA content (Figure 4) suggesting to be a usefull dietary strategy. The basal level of VA and RA as well as the increase registered after oil intake obtained in ewes (Table 4) were lower than those observed in grazing dairy cows consuming similar blends of SO and LO [49]. Enrichment of ewe's milk and cheese with these bioactive compounds (VA, RA) and also with linolenic acid has gained relevance due to the promising results on human health.…”