Association of immediate postpartum plasma calcium concentration with early-lactation clinical diseases, culling, reproduction, and milk production in Holstein cows

Abstract

The objective of this study was to evaluate the association of postpartum plasma Ca concentration with early-lactation disease outcomes, culling within 60 d in milk, pregnancy to first service, and milk production. A total of 1,453 cows from 5 commercial dairy farms in New York State were enrolled in a prospective cohort study from February to November 2015. Blood samples were collected within 12 h of parturition, and plasma was submitted to a diagnostic laboratory for total Ca measurement. Early-lactation disease, reproductive performance, and milk production from Dairy Herd Improvement Association (DHIA) test-day data were compiled from each farm's management software. Multivariable Poisson regression models were built to evaluate the association of plasma Ca with the risks of retained placenta (RP), metritis, displaced abomasum (DA), clinical mastitis, culling within 60 d in milk, and pregnancy to first service. Repeated-measures ANOVA were used to evaluate the association of Ca at parturition with milk production across the first 9 DHIA tests. Herd was considered a random effect in all models. Primiparous cows were modeled separately from multiparous cows if differential responses were observed. Calcium was not associated with the risk of RP, metritis, clinical mastitis, or pregnancy to first service in primiparous or multiparous cows. For multiparous cows only, higher Ca concentration tended to be associated with increased culling within the first 60 d in milk. Multiparous cows with Ca ≤1.85 mmol/L had an increased risk of being diagnosed with a DA compared with cows with Ca >1.85 mmol/L. For the milk production models, Ca was not associated with the amount of milk produced within the first 9 DHIA tests in primiparous cows; however, multiparous cows with Ca ≤1.95 mmol/L produced, on average, 1.1 kg more milk per day across the 9 DHIA tests than their multiparous counterparts with Ca >1.95 mmol/L. Our results indicate that plasma Ca concentration measured within 12 h of parturition is a poor predictor of early-lactation health outcomes. Reduced Ca concentration in the immediate postpartum period was associated with higher milk production in multiparous cows. From these results, we caution that studies attempting to categorize subclinical hypocalcemia based on a single sample in the immediate postpartum period could misclassify the disorder.

Association of postpartum hypocalcemia with early-lactation milk yield, reproductive performance, and culling in dairy cows

“…Multiparous cows with a serum calcium concentration <2.1 mmol/L had a tendency toward higher milk yield (+0.80 kg/d) in early lactation. This is in agreement with Neves et al (2018), who investigated the association of hypocalcemia 0 to 12 h after parturition with early-lactation health, pregnancy at first AI, and milk production. Multiparous cows with a serum calcium concentration ≤1.95 mmol/L produced 1.1 kg/d more milk across the first 9 DHIA tests compared with normocalcemic multiparous cows.…”

“…and hypocalcemic animals irrespective of parity (Martinez et al, 2012;Rodríguez et al, 2017). Except for the study by Neves et al (2018), none of the aforementioned studies took previous-lactation milk yield into account. By ignoring previous-lactation milk yield, the association between hypocalcemia and milk yield might be biased.…”

Symposium review: Mechanisms of disruption of fertility by infectious diseases of the reproductive tract

“…Common diseases of dairy cows include retained fetal membranes, metritis, and endometritis (as well as cervicitis), mastitis, lameness and abomasal displacement, clinical hypocalcemia, and ketosis. All of these diseases occur most frequently in the early part of lactation and thus in the period preceding and immediately following insemination (Foditsch et al, 2016;Gilbert and Santos, 2016;Neves et al, 2018). Interestingly, all of these conditions detrimentally affect reproductive performance, whether they are infectious (metritis, endometritis, mastitis, and some cases of lameness) or noninfectious (lameness and abomasal displacement, hypocalcemia, and ketosis).…”

Epidemiology of subclinical hypocalcemia in early-lactation Holstein dairy cows: The temporal associations of plasma calcium concentration in the first 4 days in milk with disease and milk production

“…Differences in the timing relative to parturition of Ca concentration assessment and cut point used for SCH definition between studies must be considered when interpreting different studies, as these variables can majorly affect the comparability between them. Two recent studies that classified SCH within 24 h of parturition have reported no associations between blood Ca concentration with metritis (Chamberlin et al, 2013;Neves et al, 2018). To the best of our knowledge, only one study has found an association between Ca concentration and metritis when SCH assessment was performed in the first few h following calving; Wilhelm et al (2017) found that organically managed cows with a serum Ca concentration ≤2.0 mmol/L within 2 h of parturition had increased odds of being diagnosed with metritis.…”

“…However, our findings that SCH classification was dependent on parity and that optimal cut points varied by disease and production parameter analyzed are not fully unexpected. It is not uncommon to find a moderate level of correlation between parity and blood Ca concentration in the immediate postpartum period when both independent variables are to be considered in a model (Miltenburg et al, 2016;Neves et al, 2018), which might reflect an underlying biological difference in Ca metabolism by age group. Calcium partitioning in early lactation is different between parities.…”