Differences in oxidative stress levels and their association with lactational performance and health of periparturient dairy cows

By Caio Figueiredo, Veterinary Medicine Extension

The peripartum period is considered one of the most critical times in dairy cattle management, as dairy cows undergo abrupt metabolic and inflammatory shifts due to calving and onset of lactation (Figure 1). Among the several pathways that are affected during the transition period, pathways associated with lipid metabolism, immune cell modulation, and oxidation rank high highlighting the significance of such mechanisms (Ha et al., 2017; Cattaneo et al., 2021). Indeed, the aforementioned pathways are not completely independent (Ha et al., 2017) and have been associated with milk production (Du et al., 2024), reproduction (Colakoglu et al., 2017; Marei et al., 2022), and the occurrence of diseases during the transition period (Mikulková et al., 2020; Zhang et al., 2023).

Lactating cows with ketosis have been shown to have reduced blood superoxide dismutase (SOD), oxygen radical absorbance capacity (ORAC), and malondialdehyde (MDA) compared with unaffected cows (Figure 2; Zhang et al., 2023). Differences in antioxidant status were also observed between cows with and without metritis, highlighted by the increased MDA and decreased Vitamin A and E concentration observed in the blood of cows with metritis (Table 1; Mikulková et al., 2020). Differences in total antioxidant capacity were also observed between high and low milk yield cows, with reduced levels found in low milk yield cows (Figure 3; Du et al., 2024). Although the relationship between reproductive performance and antioxidant status has not been extensively explored, blood and follicular fluid β-carotene and vitamin E concentrations at 14 days postpartum were associated with the most pronounced transcriptomic differences in the granulosa cells (Marei et al., 2022). Specifically, higher levels of antioxidants led to transcriptomic changes associated with lower catabolism, increased oxidoreductase activity and signaling cascades that are known to enhance oocyte developmental competence, increased responsiveness to LH, and a higher steroidogenic activity (Marei et al., 2022).

Overall, the transition period is complex with several connected biological processes at play. Although there is a lot of research related to transition period management and biology, more specific studies related to antioxidant status are warranted given its potential to impact the health and performance of periparturient dairy cows.

Table 1. Marker of oxidative stress and antioxidant indicators in cows with metritis (M group) and healthy control cows (CO group; adapted from Mikulková et al., 2020).

Peripartal adaptations of the key tissue such as liver, mammary gland, adipose, rumen, uterus, brain, as well as the immune system. It is highlighted the main factors that influence the functional response capacity of the key tissues involved in the homeorhetic adaptation during the transition period. NEB: negative energy balance; GIT: gastro-intestinal tract; BHB: β-hydroxybutyrate; NEFA: Non-esterified fatty acids; LPS: lipopolysaccharide; HPA: hypothalamus-pituitary-adrenal axis; PIC: pro-inflammatory cytokines; BBB: blood-brain barrier.

Figure 1. Main differences in biological processes in the transition period of dairy cows (Lopreiato et al., 2020).  

Figure 2. Comparison of oxidative parameters at 21 d after calving between groups with different β-hydroxybutyric acid (BHBA) levels postpartum (*P < 0.05, **P < 0.01). The 2 groups, ketotic (n = 20) versus nonketotic (n = 33), were defined by the average concentration of BHBA >1.2 mmol/L or <0.8 mmol/L at 3, 6, 9, and 21 d relative to calving, respectively. Furthermore, on at least half of the observation days, individual observations were above or below the threshold, respectively. The minimum and maximum values of lower and upper whiskers were calculated as the first quartile (Q1) − 1.5 × interquartile range (IQR) and the third quartile (Q3) + 1.5 × IQR, respectively. The boxes represent the central 50% of the data with a central line marking the median value. The dots represent observations outside the central 50% of the data. SOD, superoxide dismutase; GPx, glutathione peroxidase; ORAC, oxygen radical absorbance capacity; MDA, malondialdehyde; GSSG (%), proportion of oxidized glutathione to total glutathione in red blood cells; Zhang et al., 2023).  

Figure 3. The liver functionality in cows exhibiting high milk yield (MY) is elevated. (A) AST. (B) TBil – total bilirubin (C) TAOC – total anti-oxidative capacity.