Production, Composition, Fatty Acids Profile and Stability of Milk and Blood Composition of Dairy Cows Fed High Polyunsaturated Fatty Acids Diets and Sticky Coffee Hull

Four lactating Holstein cows were assigned to a 4 × 4 Latin square design to determine the effects of feeding sticky coffee hull (SCH) as a source of antioxidants on dairy cows fed with high PUFA diets. The treatments (on DM basis) were control diet, diet with 30 g/kg of soybean oil, diet with 30 g/kg of soybean oil and 100 g/kg of SCH, and diet with 30 g/kg of soybean oil and 150 g/kg of SCH. Inclusion of 150 g/kg of SCH decreased the crude protein digestibility. Lower values of NDF digestibility were also observed when cows were fed with 100 g/kg and 150g/kg of SCH. The digestibility of NDT was lower in the control and 150 g/kg of SCH diets. Milk production and composition did not differ among the treatments. Inclusion of SCH increased the total polyphenols and flavonoids in the milk and reducing power as well. Soybean oil and SCH supplementation increased the LDL and total cholesterol concentration in the plasma. Milk fatty acid profile was barely altered by the treatments. In conclusion, the results confirmed that SCH added up to 15% in the diet did not alter milk production, improved its stability, and incorporated antioxidants substances in the milk, improving its quality for human health.

Mammary gene expression and activity of antioxidant enzymes and oxidative indicators in the blood, milk, mammary tissue and ruminal fluid of dairy cows fed flax meal.

The effects of flax meal (FM) on the activity of antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT)) in the blood, mammary tissue and ruminal fluid, and oxidative stress indicators (thiobarbituric acid-reactive substances(TBARS) and 1,1-diphenyl-2-picrylhydrazyl-scavenging activity) in the milk, plasma and ruminal fluid of dairy cows were determined.The mRNA abundance of the antioxidant enzymes and oxidative stress-related genes was assessed in mammary tissue. A total of eight Holstein cows were used in a double 4 x 4 Latin square design. There were four treatments in the diet: control with no FM(CON) or 5% FM (5FM), 10% FM (10FM) and 15% FM (15FM). There was an interaction between treatment and time for plasma GPx and CAT activities. Cows supplemented with FM had a linear reduction in TBARS at 2 h after feeding, and there was no treatment effect at 0, 4 and 6 h after feeding. TBARS production decreased in the milk of cows fed the 5FM and 10FM diets. There was a linear increase in nuclear factor (erythroid-derived 2)-like 2 (NFE2L2) mRNA abundance in mammary tissue with FM supplementation.A linear trend for increased mRNA abundance of the CAT gene was observed with higher concentrations of FM. The mRNA abundance of CAT, GPx1, GPx3, SOD1, SOD2, SOD3 and nuclear factor of k light polypeptide gene enhancer in B-cells (NFKB) genes was not affected by the treatment. These findings suggest that FM supplementation can improve the oxidative status of Holstein cows as suggested by decreased TBARS production in ruminal fluid 2 h post-feeding and increased NFE2L2/nuclear factor-E2-related factor 2 (Nrf2) mRNA abundance in mammary tissue.