Changes of selected biochemical indicators and electrocardiography indicators in nutritional muscular dystrophy in calves

The aim of this study was to estimate changes in selected biochemical indicators during nutritional muscular dystrophy of calves and to use electrocardiography technique in early diagnosis of this disease. The study was performed on 24 Holstein-Friesian calves of both sexes, divided into two groups. The first one was experimental group of 12 calves with symptoms of nutritional muscular dystrophy and the second one was control group of 12 clinically healthy calves administered a single i.m. injection of vitamin E + selenium preparation on the second day after birth. Blood samples were collected from all animals 3 × at 7-day intervals, starting on day 5. Blood serum was subjected to biochemical analyses to determine Se and vitamin E concentrations, aspartate aminotransferase, creatine kinase and lactate dehydrogenase activity levels. The activity of glutathione peroxidase was determined in whole blood samples. Electrocardiographic assessment was performed on day 19 in all calves. In the group of calves with symptoms of nutritional muscular dystrophy, serum Se and vitamin E concentrations were significantly (P ≤ 0.01) lower than in control, the same was true for the activity of glutathione peroxidase (P ≤ 0.01). The changes were accompanied by an increase (P ≤ 0.01) in the activity of aspartate aminotransferase, creatine kinase and lactate dehydrogenase. The electrocardiograms of experimental animals revealed elevated heart rate, accelerated sinus rhythm, increased P wave amplitude, shorter PR, QT and ST interval, narrower QRS complex, shorter T wave duration and insignificantly increased T wave amplitude; these results were indicative of arrhythmia which is observed at early stages of cardiomyopathy. This study is the first one in which electrocardiography technique was used to diagnose nutritional muscular dystrophy in calves