Short communication: Oxidative status and incidence of mastitis relative to blood α-tocopherol concentrations in the postpartum period in dairy cows

Abstract

Vitamin E supplementation, when combined with high blood α-tocopherol (>6.25 μg/mL) at dry off, has been reported to unexpectedly increased the risk for clinical mastitis in dairy cows. Furthermore, higher levels of oxidative stress in the postpartum period were related to higher risk of mastitis. The objective of the present study was to determine the relationship between various serum biomarkers of oxidative status, incidence of mastitis, and blood α-tocopherol concentrations at dry off and at calving. A total of 146 dairy cows from a commercial farm were used in an observational field study. All cows were supplemented with 3,000 and 50 IU/cow per day of all-rac-α-tocopherol during the dry period and lactation, respectively. Blood samples were collected at dry off and at calving. Serum was analyzed for α-tocopherol, levels of reactive oxygen metabolites (ROM), thiol groups (SH), and ferric-reducing ability. Three α-tocopherol groups at calving were created: high (>3 μg/mL), medium (2-3 μg/mL), and low (<2 μg/mL). Three α-tocopherol groups at dry off were created: high (>6.25 μg/mL), medium (4.25-6.25 μg/mL), and low (<4.25 μg/mL). All cases of clinical mastitis that occurred during the dry period and the entire subsequent lactation were verified by a veterinarian. No differences were observed in the incidence of mastitis between the 3 α-tocopherol groups based on the serum levels at dry off. Incidence of mastitis was 4 times lower in the high and medium groups when compared with the corresponding value for the low-α-tocopherol group based on the serum levels at calving. Lower levels of ROM and SH at dry off and at calving were found in the group of cows with the highest α-tocopherol values at dry off when compared with the corresponding values in the low-α-tocopherol group. The ROM values at dry off but not at calving were lower in the group of cows with the highest α-tocopherol values at calving when compared with the corresponding values in the low-α-tocopherol group. No differences were observed in ferric-reducing ability values between the 3 α-tocopherol groups at dry off or calving. No differences were observed in all biomarkers of oxidative status between healthy cows and those with mastitis. Thus, blood α-tocopherol is inversely related to certain biomarkers of oxidative stress in the postpartum period and incidence of mastitis. However, reduction in the incidence of mastitis is not mediated through a reduction in the levels of various biomarkers of oxidative stress.

Lactation performance and blood metabolites in lactating dairy cows micro-supplemented with <i>Moringa oleifera</i> leaf meal

“…Milk yield and quality are critical determinants of a cow's dairy value (Politis, 2012). In the current study, the absorption of by-products of phenolic digestion could have reduced inflammation caused by stress.…”

“…Vitamins, mostly A, C and E, and minerals, such as selenium, copper and zinc, have been used to mitigate oxidative stress (Politis et al, 2012). However, in confined systems, the risk of over-or undersupplying micro elements is high (Bouwstra et al, 2010), hence the overproduction of pro-oxides is common (Rizzo et al, 2013).…”

A 100-Year Review: Metabolic health indicators and management of dairy cattle

“…In subsequent work, they demonstrated that cows with higher BCS prepartum and greater BCS loss postcalving had higher concentrations of reactive oxygen metabolites, thiobarbituric acid reactive substances, and thiol groups and lower plasma superoxide dismutase activity and erythrocyte thiol groups postpartum, collectively suggestive of increased oxidative stress in cows of higher BCS and with greater BCS loss postcalving concurrent with higher NEFA and BHB concentrations postpartum in the same group (Bernabucci et al, 2005). More recently, Politis et al (2012) reported that concentrations of α-tocopherol in cows receiving high dietary levels of vitamin E (3,000 IU/d) during the dry period were inversely related with concentrations of serum reactive oxygen metabolites and thiol groups at dry-off and calving; however, these markers of oxidative stress were not related to subsequent development of mastitis.…”

“…All of the studies above that have focused on indicators of oxidative stress and inflammation, with the exception of Huzzey et al (2011Huzzey et al ( , 2015, Politis et al (2012), andPohl et al (2015), were conducted using small (generally 100 cows or less) data sets, and studies that had larger numbers of cows were conducted in 1 or 2 dairy herds. To date, we lack the type of information for these indicators that has been gleaned from largescale observational studies described above that related NEFA and BHB to outcomes across many herds with many cows.…”

Characterization of blood redox status of early and mid-late lactating dairy cows

“…In these periods the energy requirement significantly increases, essentially to support milk production, and the physiological adaptation to this condition is represented by the implementation of metabolic activities and by an extensive mobilization of body fat reserves, particularly in early lactation. The accumulation of triglycerides in the liver and the increase of lipid metabolites concentration in the blood result in the enhancement of ROS production, decrease of paraoxonase activity, and onset of oxidative stress (Turk et al, 2008;Morris et al, 2009;Pilarczyk et al, 2012), which in turn leads to a higher vulnerability of dairy cows to bacterial infections (Kehrli et al, 1989;Mallard et al, 1998;Keane et al, 2006;van Knegsel et al, 2007), thus causing metabolic disorders and diseases (LeBlanc et al, 2004;Rizzo et al, 2007Rizzo et al, , 2009LeBlanc, 2008;Sharma et al, 2011;Politis et al, 2012;Sordillo and Raphael, 2013;Wathes et al, 2013).…”