J.A.A. McArt

Hyperketonemia in early lactation dairy cattle: a deterministic estimate of component and total cost per case.

The purpose of this study was to develop a deterministic economic model to estimate the costs associated with (1) the component cost per case of hyperketonemia (HYK) and (2) the total cost per case of HYK when accounting for costs related to HYK-attributed diseases. Data from current literature was used to model the incidence and risks of HYK (defined as a blood β-hydroxybutyrate concentration≥1.2 mmol/L), displaced abomasa (DA), metritis, disease associations, milk production, culling, and reproductive outcomes. The component cost of HYK was estimated based on 1,000 calvings per year; the incidence of HYK in primiparous and multiparous animals; the percent of animals receiving clinical treatment; the direct costs of diagnostics, therapeutics, labor, and death loss; and the indirect costs of future milk production losses, future culling losses, and reproduction losses. Costs attributable to DA and metritis were estimated based on the incidence of each disease in the first 30 DIM; the number of cases of each disease attributable to HYK; the direct costs of diagnostics, therapeutics, discarded milk during treatment and the withdrawal period, veterinary service (DA only), and death loss; and the indirect costs of future milk production losses, future culling losses, and reproduction losses. The component cost per case of HYK was estimated at

Dry period and parturient predictors of early lactation hyperketonemia in dairy cattle.

134 and

Short communication: Concentrations of nonesterified fatty acids and β-hydroxybutyrate in dairy cows are not well correlated during the transition period

111 for primiparous and multiparous animals, respectively; the average component cost per case of HYK was estimated to be

Risk factors for postpartum problems in dairy cows: Explanatory and predictive modeling

117. Thirty-four percent of the component cost of HYK was due to future reproductive losses, 26% to death loss, 26% to future milk production losses, 8% to future culling losses, 3% to therapeutics, 2% to labor, and 1% to diagnostics. The total cost per case of HYK was estimated at

Effects of chromium propionate supplementation during the periparturient period and early lactation on metabolism, performance, and cytological endometritis in dairy cows

375 and

Technical note: Comparison of 4 electronic handheld meters for diagnosing hyperketonemia in dairy cows

256 for primiparous and multiparous animals, respectively; the average total cost per case of HYK was

Risk factors associated with postpartum subclinical hypocalcemia in dairy cows

289. Forty-one percent of the total cost of HYK was due to the component cost of HYK, 33% to costs attributable to metritis, and 26% to costs attributable to DA. The high total cost of HYK at reported incidences of 40 to 60% highlights the importance of appropriate transition cow nutrition and management to decrease the effect of HYK.

A stochastic estimate of the economic impact of oral calcium supplementation in postparturient dairy cows

The purpose was to determine important dry and calving period predictors of (1) a cow developing hyperketonemia at any time between 3 and 16 d in milk (DIM) and (2) a cow having hyperketonemia at her first β-hydroxybutyrate (BHBA) test after calving (between 3 and 5 DIM). Cows from 4 freestall dairy herds [2 in New York (NY) and 2 in Wisconsin] were enrolled at 266 d carried calf. Precalving data included body condition score, locomotion score, and blood nonesterified fatty acids (NEFA) concentration; calving-associated data included previous days carried calf, calving ease, calf sex, twins, stillbirth, and parity. Cows were each tested 6 times for hyperketonemia from 3 to 16 DIM on Mondays, Wednesdays, and Fridays using the Precision Xtra meter (Abbott Laboratories, Abbott Park, IL). Hyperketonemia was defined as a blood BHBA concentration of ≥1.2 mmol/L. Multivariable fixed-effects Poisson regression models were developed to predict the probability of a cow developing hyperketonemia between either 3 and 16 DIM or at her first BHBA test. As only the NY herds had precalving NEFA data, each prediction model was developed twice: once with data from all 4 herds (n=1,672) and once with data from only the NY herds (n=544). For the models with data from all 4 herds, increased body condition score group and an interaction between advanced parity and herd were important predictors of hyperketonemia development at any time from 3 to 16 DIM; calf sex (male), herd, and an advanced parity by increased body condition score group interaction were important predictors of hyperketonemia development between 3 and 5 DIM. The 4-herd models had a 64 and 78% predictive concordance for hyperketonemia between 3 and 16 DIM and at first BHBA test, respectively. For the models with data from the NY herds only, increased NEFA, calf sex (male), advanced parity, and herd were found to be important predictors of hyperketonemia development at any time from 3 to 16 DIM; increased NEFA, calf sex (male), decreased calving ease, stillbirth, and advanced parity were important predictors of having hyperketonemia at first BHBA test. The NY models had a 69 and 87% predictive concordance, respectively. These results may help identify at-risk animals and improve dry-cow management strategies before hyperketonemia develops.

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

The objective was to use longitudinal data of blood nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA) concentrations to describe the relationship between NEFA and BHBA in dairy cows during the periparturient period. Blood NEFA and BHBA concentration data collected from d 21 prepartum to 21 postpartum for 269 multiparous Holstein cows were selected from 4 different studies carried out within our research groups. Overall, NEFA concentrations were increased beginning near parturition with a relatively steady elevation of NEFA through d 9, after which concentrations gradually decreased. Prepartum BHBA concentrations began to increase beginning several days before parturition, continued to increase during the first week after parturition, and remained elevated through d 21 postpartum. Of the 269 cows included in the data set, 117 cows (43.5%) had at least one postpartum hyperketonemic event (BHBA ≥1.2mmol/L), and 202 cows (75.1%) had at least one event of elevated postpartum NEFA concentrations (≥0.70mmol/L) between 3 and 21 d in milk. Area under the curve (AUC) was used to investigate relationships between metabolites over time. Overall, the correlations between transition period NEFA and BHBA AUC were weak. We detected a negative correlation between prepartum BHBA AUC and postpartum NEFA AUC (r=-0.26). A positive correlation existed between postpartum NEFA AUC and postpartum BHBA AUC; however, the correlation coefficient was low (r=0.26). Large variation was found between the day of maximum NEFA concentration within the first 21 d in milk and day of maximum BHBA concentration for the same period. The mean and median times of maximum NEFA concentration were 6.8 and 6 d, respectively, whereas the mean and median times of maximum BHBA were 9.6 and 8 d, respectively; however, the range in days for both the mean and median day of maximum concentrations was very large. Overall, our data set indicates a weak relationship between blood concentrations of NEFA and BHBA during the periparturient period of dairy cows, suggesting that elevated concentrations of one should not be extrapolated to suggest elevated concentrations of the other metabolite.

Thoracic ultrasound assessment of lung consolidation at weaning in Holstein dairy heifers: Reproductive performance and survival

The postpartum period is associated with a high incidence of most dairy cattle diseases and a high risk of removal from the herd. Postpartum diseases often share risk factors, and these factors may trigger a cascade of other diseases. The objective of this cohort study was to derive explanatory and predictive models for treatment or removal from the herd within the first 30 d in milk (TXR30). The TXR30 outcome was specifically defined as ≥1 treatment for ≥1 occurrence of milk fever, retained placenta, metritis, ketosis, displaced abomasum, lameness, or pneumonia; removal from the herd (sold or died); or both treatment and later herd removal. The study population consisted of 765 multiparous and 544 primiparous cows (predominantly Holstein) from 4 large commercial freestall-housed dairy herds. Treatment or removal from the herd was recorded as a binary outcome for each cow. Potential explanatory and predictive variables were limited to routine cow data that could be collected either before or within 24 h of calving. Models for multiparous and primiparous cows were developed separately because previous lactation variables are available only for multiparous cows. Adjusted odds ratios for TXR30 in the explanatory model for the multiparous cohort were 2.1 for lactation 3 compared with lactation 2, and 2.3 for lactation 4 or greater compared with lactation 2; 2.3 for locomotion score 3 or 4 compared with score 1; 3.3 for an abnormality at calving compared with no calving abnormality; 1.8 for each 1-standard deviation increase in previous lactation length; and 0.4 for each 5,000-kg increment in previous lactation milk yield in cows with longer previous lactation length. The final predictive model for TXR30 in multiparous cows included predictors similar but not identical to those included in the explanatory model. The area under the curve for the receiver operating characteristic curve from the final predictive model for the multiparous cohort was 0.70, with 60% sensitivity. For the primiparous cohort, calving abnormality increased the odds of TXR30 and was the only variable included in both the explanatory and predictive models. The area under the curve for the receiver operating characteristic curve from the final predictive model for the primiparous cohort was 0.66, with 35% sensitivity. This study identified key risk factors for TXR30 and developed equations for the prediction of TXR30. This information can help dairy producers better understand causes of postpartum problems.