Disturbances in the acid-base and electrolyte balance and changes in serum mineral concentrations in calves diagnosed with nutritional muscular dystrophy
Żarczyńska K., Radwińska J., Snarska A., Rękawek W., Procajło A.
Selenium is an essential nutrient, which is crucial for proper body function. Its role is complemented by vitamin E. Nutritional muscular dystrophy (NMD) is one of the main disorders caused by a selenium deficiency. NMD most often affects calves at the age of 4 to 6 weeks. The study was performed on 40 Holstein-Friesian (HF) calves divided into two groups of 20 animals each. Control group calves were administered an IM injection of selenium and vitamin E on the second day of life. The experimental group comprised calves with symptoms of NMD. Samples of the biceps femoris muscle were collected from six animals in each group for histopathological analyses to confirm changes in muscle parameters. Blood samples were obtained from all animals on three different dates. The following blood parameters were determined in laboratory analyses: pH, pCO2, pO2, HCO3–, BE, O2SAT, the concentrations of Na+, K+, Cl–, and Ca and P levels. A drop in pH, an increase in the partial pressure of carbon dioxide, a decrease in the partial pressure of oxygen, a significant decrease in bicarbonate ion concentrations and hemoglobin oxygen saturation as well as a base deficit were reported in the group of calves demonstrating symptoms of NMD. The above changes point to the development of uncompensated metabolic acidosis due to increased levels of pyruvic acid and lactic acid produced as a result of anaerobic processes that accompany muscle fiber degeneration. Minor fluctuations in sodium and chloride levels were observed throughout the experiment, but their concentrations remained within the norm in animal groups. Potassium levels were significantly higher in the experimental group than in the control group. The serum concentrations of inorganic phosphorus and calcium were within the reference range in both groups. In calves, NMD leads to disruptions in the acid-base equilibrium and the electrolyte balance, which are manifested by uncompensated metabolic acidosis and hyperkalemia. Significant changes in calcium and phosphorus levels are not observed in the blood serum of calves affected by NMD.
Żarczyńska K., Radwińska J., Snarska A., Rękawek W., Procajło A. 2013. Disturbances in the acid-base and electrolyte balance and changes in serum mineral concentrations in calves diagnosed with nutritional muscular dystrophy. J. Elem. 18(2): 307-315; DOI: 10.5601/jelem.2013.18.2.10.
NMD, calves, acid-base balance, electrolytes, serum mineral concentrations