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Clinical utility of plasma progesterone and blood and plasma glucose concentrations in predicting parturition in Holstein cows

Hiew MWH, Megahed AA, Horstman LA, Constable PD

J Dairy Sci, 2020 Jun;103(6):5575-5590.
PMID: 32307156 DOI: 10.3168/jds.2019-17800

An accurate, practical, and low-cost method for predicting parturition is urgently needed in the dairy industry. The objective of this study was to evaluate changes in plasma progesterone concentration ([prog]) and glucose concentration in whole blood ([gluc]b) and plasma ([gluc]p) as predictors of parturition within 6, 12, and 24 h in primiparous and multiparous Holstein cows. Blood samples were obtained daily at approximately 0900 h from 34 primiparous and 72 multiparous Holstein cows in late gestation and the time of calving recorded to the nearest hour. Plasma [prog] was measured using an ELISA, and [gluc]b and [gluc]p using a low-cost point-of-care glucose meter. The optimal cut-point for predicting parturition was determined using binomial logistic regression with general estimating equations, because the data set consisted of repeated measures for each cow. Diagnostic test performance was evaluated by comparing the area under the receiver operating characteristic curve (AUC) and calculating the sensitivity, specificity, and κ at the optimal cut-point for predicting parturition. Plasma [prog] was the most accurate predictor of parturition within 24 h (AUC = 0.96) and 12 h (AUC = 0.93), whereas [gluc]b was the most accurate predictor of parturition within 6 h (primiparous, AUC = 0.96; multiparous, AUC = 0.86). We conclude that a decrease in plasma [prog] is currently the most accurate test for predicting calving within 24 h. Measurement of [gluc]b is a promising new test for the cow-side prediction of parturition in dairy cows due to its accuracy, practicality, and low cost.

Matched MeSH terms: Cattle/blood*
Fulltext Clinical Utility of Plasma Fructosamine Concentration as a Hypoglycemic Biomarker during Early Lactation in Dairy Cattle

Megahed AA, Hiew MWH, Constable PD

J. Vet. Intern. Med., 2018 Mar;32(2):846-852.
PMID: 29424465 DOI: 10.1111/jvim.15049

BACKGROUND: Plasma fructosamine concentration ([FRA]) is a widely used long term hyperglycemic biomarker in humans and dogs, but its clinical usefulness as a hypoglycemic biomarker in dairy cattle is uncertain.
OBJECTIVES: To evaluate the relationship between plasma [FRA] and glucose concentration ([gluc]) as well as indices of energy balance during early lactation in dairy cattle, and to characterize the influence of plasma total protein concentration ([TP]) and albumin concentration ([albumin]) on [FRA].
ANIMALS: Convenience sample comprising 103 periparturient Holstein-Friesian cattle.
METHODS: Plasma [gluc], [TP], [albumin], and other clinicopathologic indices of energy status were determined periodically from Day 4 postpartum. Body condition score (BCS) was assessed, and backfat thickness (BFT) and longissimus dorsi muscle thickness (LDT) were measured ultrasonographically. Plasma [FRA] was measured at approximately 28 days postpartum. Associations between plasma [FRA] and study variables were evaluated using Spearman's rho and stepwise forward linear regression. Statistical significance was declared at P

Matched MeSH terms: Cattle/blood
Changes in skeletal muscle thickness and echogenicity and plasma creatinine concentration as indicators of protein and intramuscular fat mobilization in periparturient dairy cows

Megahed AA, Hiew MWH, Ragland D, Constable PD

J Dairy Sci, 2019 Jun;102(6):5550-5565.
PMID: 30954258 DOI: 10.3168/jds.2018-15063

High-producing dairy cows experience a state of negative energy balance in the periparturient period that is partially addressed by increasing the rate of fat and protein mobilization. Previous studies have focused on the rate of fat mobilization, and consequently the rate of protein mobilization has not been well characterized. The objective of this study was therefore to determine the change in indicators of muscle mass during early lactation using ultrasonographic measurement of muscle thickness and changes in plasma creatinine concentration. The maximum thickness of the gluteus medius and longissimus dorsi muscles of 106 Holstein cows (34 primiparous, 72 multiparous) was determined ultrasonographically on d -3, 0, 3, 7, 14, 21, and 28 relative to the day of parturition. Plasma creatinine concentration was measured periodically during the same period. Mixed models analysis and Passing-Bablok regression were used to analyze the data. Gluteus medius thickness, longissimus dorsi loin thickness (LDLT), and longissimus dorsi thoracic thickness (LDTT) were decreased at 28 d postpartum compared with d 3 antepartum. Plasma creatinine concentration was weakly associated with gluteus medius thickness, LDLT, and LDTT (Spearman's rho = 0.31, 0.39, and 0.32, respectively). Plasma creatinine concentration in primiparous and multiparous cows at 28 d postpartum decreased by 0.24 and 0.30 mg/dL, respectively, compared with values 3 d antepartum. We concluded that ultrasonographic measurement of LDLT and LDTT and change in plasma creatinine concentration may provide practical methods for monitoring the rate of protein mobilization in periparturient dairy cows. Ultrasonographic examination of LDLT and LDTT therefore complements ultrasonographic measurement of backfat thickness and may be useful in the evaluation of energy reserve mobilization in periparturient dairy cows.

Matched MeSH terms: Cattle/blood*

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