Redox and immune response in early-lactating dairy cows supplemented with vitamin E or plant extract.

In dairy cows, early lactation is a period prone to oxidative stress, inflammation and health problems. Our objective was to investigate the effects of 2 strategies of nutritional supplementation on physiological and immunological status of early lactating cows. The first strategy consisted of supplementing vitamin E (all-rac-α-tocopheryl acetate) from 3 weeks before calving (3,000 IU/d before and 1,000 IU/d after calving). The other strategy consisted of supplementing plant extracts (Sambucus nigra, Salix alba, Laurus nobilis, Harpagophytum procumbens, Silybum marianum and Arctium lappa, QUALIMILK product from BIODEVAS Laboratoires, QPB plant extracts) from calving (10 g/d). In anticipation of cows being removed due to health issues or changes in calving dates, 51 Holstein dairy cows were assigned to 3 groups of 17 cows with a final target of 15 cows per group. Each group was randomly assigned to one of the 3 compared treatments: control group (final n = 15), vitamin E group (final n = 16), and QPB plant extract group (final n = 14). Their redox and immune status were monitored during the first 12 weeks of lactation, every 4 weeks. In wk 12, malondialdehyde levels in plasma tended to be lower in the vitamin E and QPB plant extract groups than in the control group. The vitamin E and QPB plant extract groups had lower ex vivo plasma CCL4, IL6 and IL8 cytokine levels, lower proportions of blood regulatory neutrophils, and less ROS production by blood neutrophils than the control group. In terms of immune response, the expression of FABP3 in milk mammary epithelial cells was downregulated in multiparous cows supplemented with vitamin E and QPB plant extracts. Therefore, supplementation with either vitamin E before and after calving or QPB plant extracts after calving clearly reduced the ex vivo inflammatory response and enhance a specific ex vivo immune response shown to be involved in the fight against mastitis.