Increase in white blood cell counts by pegbovigrastim in primiparous and multiparous grazing dairy cows and the interaction with prepartum body condition score and non-esterified fatty acids concentration

Abstract

The objective of this study was to determine if parity affected the effect of pegbovigrastim (PEG) treatment on white blood cell (WBC) counts in grazing dairy cows. Additionally, the association of prepartum body condition score (BCS) and non-esterified fatty acid (Pre-NEFA) concentration with WBC counts was investigated. The effect of early-lactation disease was included in the statistical analysis. A randomized controlled trial on four commercial grazing dairy farms was performed. Holstein primiparous (Control = 87, PEG = 89) and multiparous (Control = 181, PEG = 184) cows were randomly assigned to one of two treatments: first PEG dose 8 ± 5 (mean ± SD) days before the expected calving date and a second dose within 24 h after calving (PEG) compared to untreated controls (Control). Treatment effects were evaluated with mixed linear regression models. Treatment with PEG increased WBC, neutrophil, lymphocyte and monocyte counts at 6 ± 1 (mean ± SD) days in milk. Parity, BCS and their interactions with treatment were not associated with WBC counts. In control cows, Pre-NEFA concentration was associated with reduced WBC, neutrophil and lymphocyte counts and tended to be associated with reduced monocyte counts. Pegbovigrastim treatment reversed the negative association of Pre-NEFA concentration with neutrophil and monocyte counts and tended to reverse the negative association of Pre-NEFA concentration with WBC counts. In the PEG treated group, cows diagnosed with retained placenta or metritis showed lower neutrophil counts when compared to PEG treated cows without these clinical diseases. These data confirm that PEG treatment increases WBC, neutrophil, lymphocyte and monocyte counts in grazing dairy cows and that this effect is independent of parity. Pegbovigrastim treatment reversed the negative association of Pre-NEFA concentration with neutrophil and monocyte counts, and tended to reverse the negative association of Pre-NEFA concentration with WBC counts.

Effect of pegbovigrastim on clinical mastitis and uterine disease during a full lactation in grazing dairy cows

“…A more robust vaginal discharge due to a greater intra-uterine neutrophil influx in PEG treated cows was suggested by Ruiz et al [ 13 ]. This hypothesis is supported by the findings of lower blood neutrophil counts [ 11 ] and higher neutrophil counts in the vagina in PEG cows with metritis compared to PEG cows without metritis [ 14 ]. As expected [ 22 ], primiparous cows had a higher metritis occurrence, while no treatment by parity interaction was detected.…”

“…This suggests that PEG has a differential effect according to the Pre-NEFA category. We expected a stronger association based on our recent findings that PEG reverts the negative association between Pre-NEFA and neutrophil counts [ 11 ]. Analysis of the estimated least squares means differences by Pre-NEFA category shows that, in high Pre-NEFA cows, PEG treatment significantly reduced the occurrence of a first case of CM during the first 30 d of lactation by 35%.…”

“…Pegbovigrastim increases circulating white blood cell (WBC) and neutrophil counts and myeloperoxidase exocytosis [ 9 , 10 ]. Recently, we found that prepartum NEFA (Pre-NEFA) concentrations were associated with reduced neutrophil counts, and that PEG treatment reversed this negative association [ 11 ]. It has been reported that treatment with PEG reduced the occurrence of clinical mastitis (CM) during the first 30 days in milk (DIM).…”

Effect of pegbovigrastim on fertility and culling in grazing dairy cows and its association with prepartum nonesterified fatty acids

“…Recently, we showed that treatment with PEG prevented the negative association of prepartum NEFA concentration with postpartum neutrophil counts (Barca et al, 2021a). In addition, we found that PEG reduced the occurrence of a first case of CM during the first 30 DIM, particularly in cows with elevated prepartum NEFA concentrations and in cows with excessive prepartum BCS (Barca et al, 2021b).…”

“…Metabolites related to negative energy balance (NEB), such as nonesterified fatty acids (NEFA) and BHB, have been identified as immunosuppressants (Ingvartsen and Moyes, 2015). Elevated NEFA concentrations were associated with decreased white blood cell and neutrophil counts (Hachenberg et al, 2007;Barca et al, 2021a) and impaired neutrophil and lymphocyte function (Lacetera et al, 2005;LeBlanc, 2020). Moreover, epidemiological studies have shown that elevated NEFA concentrations are associated with increased risk of diseases such as mastitis, retained placenta (RP), and metritis (LeBlanc et al, 2004;Melendez et al, 2009;Galvão et al, 2010).…”