Changes of biochemical environment and body weight in healthy periparturient Lipizzan mares

The aims of this study were to determine the concentrations of calcium, magnesium, phosphorus, chlorine, potassium, sodium, urea, total cholesterol, triacylglycerols, non-esterified fatty acids, total protein, creatinine, total bilirubin, aspartate aminotransferase, insulin, insulin growth factor 1, and glucose in the blood serum and to monitor the body weight changes in nine clinically healthy Lipizzan mares at weekly intervals within 2 weeks before and 2 weeks after the parturition. A significant body weight loss (P < 0.01) was found in the mares after the foaling. The peak of insulin growth factor 1 concentration in serum was reached at the day of parturition and similar patterns were revealed for the concentrations of insulin and glucose. After parturition, all these indices were significantly decreased. The concentrations of phosphorus and triacylglycerols were decreased, while the concentrations of potassium and sodium were increased at the day of parturition. Moreover, the concentration of non-esterified fatty acids was increased at the day of parturition (P < 0.05) with a tendency to higher values even on the 7th day postpartum. Other studied indexes remained relatively stable throughout the transition period. We can conclude that periparturient mares face some degree of negative energy balance with concomitant significant homeostatic and homeorhetic changes. For this reason, our results can be used as a basis for reference values and a diagnostic tool to examine the health status in horses during the transition period. Horse, metabolic indices, transition phase, homeostatic changes, homeorhetic changes The peripartal period is a very challenging interval of life of dams due to the decreased feed intake in the late gestation that is accompanied by the increasing metabolic demands of the foetus, and then after the parturition due to the onset of milk production to cover the nutritional requirements of the offspring as well as for the postpartum (p.p.) recovery of the dam. It is well understood mostly from research performed on high-yielding animals, that all these events trigger different cascades of metabolic reactions as a part of the adaptation mechanisms of the organism of the dam concomitant to the transition from the pregnant non-lactating state to the non-pregnant lactating state. From the physiological point of view, the endocrine changes in mares around the parturition have been well described but only limited literature data are available in the field of biochemistry. It is known that especially during the transition period, both pregnant and lactating mares are highly vulnerable to various health disorders which could lead to different productive and reproductive problems (Reed et al. 2010). For this reason, it is recommended to perform a set of metabolic blood tests in dams over the transition to determine the dynamics of homeostatic and homeorhetic changes, and thus predict the course of puerperium in these animals. In general, the assessment of energy balance (non-esterified fatty acids (NEFA), glucose, triacylglycerols (TAG), etc.) is one of the most important tools when considering an animal’s health, and the productive and reproductive performance as reviewed by Esposito et al. (2014). According to these authors, the interpretation of the results of ACTA VET. BRNO 2017, 86: 67–74; https://doi.org/10.2754/avb201786010067 Address for correspondence: MVDr. Vladimir Petrovic PhD. Department of Pharmacology and Toxicology University of Veterinary Medicine and Pharmacy Komenskeho 73, 041 81 Kosice, Slovak Republic Phone: +421 907 816 486 E-mail: vladimir.petrovic@uvlf.sk http://actavet.vfu. cz/ metabolic profile tests should be taken into account only in light of the health history and total clinical examination of a mare, as well as on the bases of dietary management and welfare in the herd. Therefore, the objectives of our study were to determine the dynamic changes of calcium, magnesium, phosphorus, chlorine, potassium, sodium, urea, total cholesterol, triacylglycerols, non-esterified fatty acids, total protein, creatinine, total bilirubin, aspartate aminotransferase, insulin, insulin growth factor 1, glucose and body weight in healthy periparturient Lipizzan mares from the 2nd week before to the 2nd week after foaling. Materials and Methods