Haptoglobin as a marker for health and management of periparturient dairy cows

By Caio Figueiredo, Veterinary Medicine Extension

Over the years the structure of the US dairy industry has shifted toward larger operations. Such a shift has led to different strategies for producers and practitioners to provide animal health oversight and management. The transition period in particular is marked by a high prevalence of inflammatory/metabolic diseases requiring animal health surveillance methods that can serve as management report cards.  The use of several blood metabolites associated with cow metabolic status and inflammation (beta hydroxy butyrate, non-esterified fatty acids, and haptoglobin; Hp) has been investigated previously. In this article, we will review some of the most recent literature related to Hp and its relationship with cow health and performance.

Haptoglobin is an acute-phase protein that is critical for the elimination of free hemoglobin and the neutralization of oxidative damage. Several studies have associated differences in blood Hp concentration with the occurrence of inflammatory diseases in periparturient dairy cows, and some studies have proposed the use of Hp for early detection of diseases (Barragan et al., 2019; Schmitt et al., 2021). For instance, higher Hp concentrations were observed in cows with higher vaginal discharge scores (Metricheck score; Barragan et al., 2019; Schmitt et al., 2021), and Hp concentrations were positively correlated with rectal temperature (Figure 1; Schmitt et al., 2021). Although blood Hp concentration has been consistently higher in sick cows compared with healthy counterparts, the cut-offs for Hp concentration that represent sick cows have not been as consistent. For instance, different cut-off values for a blood Hp concentration representing affected cows were observed when analyses considered: 1) the proportion of cows culled within 30 days in milk (DIM; ≥ 0.45 g/L; Kerwin et al., 2022a), 2) cows that developed metritis (≥ 1 g/L; Huzzey et al., 2009; ≥ 0.96 g/L; Kerwin et al., 2022a), and 3) cows with clinical cure failure for metritis (≥ 0.48 g/L; Machado et al., 2020).

A high prevalence of elevated blood Hp (≥ 0.45 g/L) in periparturient cows across 72 herds in the northeastern US was previously observed (Figure 2), which highlights the importance of optimized transition cow management. High Hp concentrations have been associated with detrimental impacts on milk production and reproduction performance. Cows with Hp concentrations ≥0.45 g/L produced 492 kg less ME305 milk than cows with Hp concentrations <0.45 g/L (Kerwin et al., 2022c).  In addition, cows with Hp concentrations ≥0.45 g/L had a 28% decreased hazard (HR) of pregnancy within 150 DIM compared with cows with Hp concentration <0.45 g/L (HR = 0.72), and required an additional 15 median days to pregnancy (115 vs. 100 days; Kerwin et al., 2022c). Considering the detrimental impacts in cow performance associated with high Hp, researchers have assessed pen-level and herd-level factors associated with the issue. For instance, Kerwin et al., 2022b reported that pen-level factors such as feed pushup frequency (≥5x/day vs. <5x/day) and commingling primiparous and multiparous cows in the same postpartum pen were associated with differences in the number of cows with elevated levels of Hp. Additionally, at the herd-level the time cows remain in the calving pen after calving (>8h vs. ≤8h), parity, and time locked in the fresh pen were also associated with differences in likelihood of cow with elevated levels of Hp (Kerwin et al., 2022b). Overall, using blood Hp may prove to be an effective an animal health and management surveillance strategy to aid producers and practitioners in improving dairy operations.

Figure 1. Boxplots and scatterplots illustrating the association between the concentrations of haptoglobin in serum of cows within 0–8 days postpartum. with the Metricheck score and rectal body temperature, respectively (Adapted from Schmitt et al., 2021).
Figure 2. The prevalence of herds in which at least 20% of sampled cows had postpartum haptoglobin concentration ≥0.45 g/L, for a prospective cohort study involving 72 farms across the northeastern United States (Adapted from Kerwin et al., 2022a).