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Clinical biochemistry of pregnant and nursing mares.
Abstract: Pregnancy and lactation result in increased metabolic demands. Although homeostatic mechanisms function to keep substances in blood at relatively constant levels, some changes in the concentrations of routine clinical chemistry analytes are likely to occur. Objective: The purpose of this study was to determine what physiological changes occur in serum clinical biochemistry analytes in pregnant and nursing mares, and to determine whether the changes were substantial enough to warrant separate reference intervals for pregnant or lactating horses. Methods: Forty-two Quarter Horse, Thoroughbred, Saddlebred, Standardbred and Morgan mares were entered into the study while pregnant. They were bled once each month through birth. Studies were continued on 20 mares until their foals were weaned. Test results were tabulated by time before or after birth. Serum biochemistry values were determined by standard methods using automated analyzers. Test results were analyzed using the Kruskal-Wallis 1-way ANOVA on ranks. If a significant difference was found (P<.05), Dunn's multiple comparison procedure was performed on all pairs. Results from pregnant and nursing mares also were compared with a reference group of 19 open, nonlactating mares. Results: Serum triglyceride, potassium, creatinine, and total bilirubin concentrations were lower during lactation than during pregnancy. Serum calcium concentration also was slightly decreased at 2 time points during lactation. Triglyceride concentration was highest during midgestation, while bilirubin and creatinine values increased, and potassium and calcium remained constant during pregnancy. Serum urea concentration also remained constant during pregnancy but increased during lactation. Serum phosphate concentration was lowest during midgestation and highest during lactation. Total CO2 values were highest, and anion gaps were lowest, during midgestation. No significant differences were found in serum albumin, globulin, albumin:globulin ratio, total protein, or glucose values. When compared with the reference group of open mares, serum triglyceride, potassium, bilirubin, and total CO2 concentrations were lower, and anion gap was higher in horses that were nursing. Conclusions: Although most biochemical values remained relatively constant, significant differences were observed during pregnancy and lactation. Changes in the concentrations of triglycerides, potassium, bilirubin, total CO2, and anion gap during lactation were substantial enough to warrant separate reference intervals for lactating horses.
Publication Date: 2005-09-01 PubMed ID: 16134073DOI: 10.1111/j.1939-165x.2005.tb00049.xGoogle Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
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The study investigates physiological changes in blood substances of pregnant and nursing mares and determines whether these changes are significant enough to necessitate separate reference points for these special conditions. The researchers found that while most biochemical values remained stable, significant variations were observed in elements like triglycerides, potassium, bilirubin, total CO2, and the anion gap during lactation, therefore proposing separate reference intervals for lactating horses.
Study Purpose and Design
- The study aimed to understand the physiological changes in serum clinical biochemistry analytes in pregnant and nursing mares. It also aimed to determine whether these changes were significant enough to warrant separate reference intervals for pregnant or lactating horses.
- This research was conducted on 42 horses of various breeds who were pregnant at the time of entry into the study. Their blood was tested monthly until birth, and for 20 of the horses, testing continued until the foaling period was complete.
- The researchers employed standard methods using automated analyzers to recognize serum biochemistry values. Kruskal-Wallis 1-way ANOVA method was used for data analysis. If any significant differences were found, Dunn’s multiple comparisons were utilized.
Study Findings
- Results showed that the concentrations of serum triglyceride, potassium, creatinine, and total bilirubin were lower during lactation than throughout pregnancy. Minimal decrease was also spotted at 2 time points during lactation for serum calcium concentration.
- On the contrary, during pregnancy, triglyceride concentration was recorded highest during mid-gestation, bilirubin and creatinine values rose, while potassium and calcium remained consistent.
- Serum phosphate concentration dropped during mid-gestation and was highest during lactation. The amount of total CO2 was maximal, and anion gaps were minimal during mid-gestation.
- No significant variations were detected in serum albumin, globulin, albumin:globulin ratio, total protein, or glucose values.
- Compared with a reference group of open, non-lactating mares, serum triglyceride, potassium, bilirubin, and total CO2 concentrations were lower, and anion gap was higher in mares who were nursing or lactating.
Study Conclusion
- Though majority of biochemical values maintained relative stability, pregnant and lactating phases exhibited significant differences.
- The observed changes in the concentrations of triglycerides, potassium, bilirubin, total CO2, and anion gap during lactation were substantial enough to necessitate separate reference intervals for lactating horses according to the findings of this study.
Cite This Article
APA
Harvey JW, Pate MG, Kivipelto J, Asquith RL.
(2005).
Clinical biochemistry of pregnant and nursing mares.
Vet Clin Pathol, 34(3), 248-254.
https://doi.org/10.1111/j.1939-165x.2005.tb00049.x Publication
Researcher Affiliations
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA. harveyj@mail.vetmed.ufl.edu
MeSH Terms
- Animals
- Blood Chemical Analysis / veterinary
- Creatinine / blood
- Female
- Horses / physiology
- Lactation / physiology
- Pregnancy
- Pregnancy, Animal / blood
- Triglycerides / blood
- Weaning
Citations
This article has been cited 13 times.- Salari F, Roncoroni C, Altomonte I, Boselli C, Brajon G, Martini M. Effects of the Physiological Status and Diet on Blood Metabolic Parameters in Amiata Dairy Donkeys. Animals (Basel) 2021 Nov 17;11(11).
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- Vernemmen I, Vera L, Van Steenkiste G, van Loon G, Decloedt A. Reference values for 2-dimensional and M-mode echocardiography in Friesian and Warmblood horses. J Vet Intern Med 2020 Nov;34(6):2701-2709.
- Nabi G, Robeck TR, Hao Y, Wang D. Hematologic and Biochemical Reference Interval Development and the Effect of Age, Sex, Season, and Location on Hematologic Analyte Concentrations in Critically Endangered Yangtze Finless Porpoise (Neophocaena asiaeorientalis ssp. asiaeorientalis). Front Physiol 2019;10:792.
- Nabi G, Hao Y, Robeck TR, Jinsong Z, Wang D. Physiological consequences of biologic state and habitat dynamics on the critically endangered Yangtze finless porpoises (Neophocaena asiaeorientalis ssp. asiaeorientalis) dwelling in the wild and semi-natural environment. Conserv Physiol 2018;6(1):coy072.
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