The influence of selenium deficiency on chosen biochemical parameters and histopathological changes in muscles of goat kids

The research was conducted on 40 young alpine goats (kids) divided into two groups. First group consisted of 20 kids demonstrating clinical signs of muscular dystrophy. Second group was a control and consisted of 20 animals that received intramuscular injection (2ml per animal) of vitamin E and selenium preparation containing in 1ml 50 mg of tocopherol acetate, 0.5mg of sodium selenite and solvent on 2nd day of life. The kids were clinically examined and blood for laboratory analyses was sampled three times from day 5 of their life in 10 day intervals. In addition, six 24 days old kids demonstrating clinical signs of muscular dystrophy and six control kids were subjected to biceps femoris biopsy. Serum total protein, glucose, triglycerides, cholesterol as well as AST, CK and LDH were determined in all the animals. In addition, the activity of glutathione peroxidase (GSH-Px) was determined in whole blood and serum concentrations of selenium and vitamin E were deter-mined in 6 kids from each group. Total lactate dehydrogenase activity and its separation into isoenzymatic fractions were determined in the collected biopsy material. The muscle samples collected were additionally subjected to histopathological examination consisting of HE staining and HBFP staining to detect necrotic muscle fibers. Symptoms of muscular dystrophy began to appear in the first group between 17 and 23 days of age and included tremors of the limbs, poor posture, stilt gait and increased time of laying. The control animals did not show any symptoms of the disease during the experiment. Hypo-proteinemia, hypoglycemia, cholesterol reduction and elevated triglycerides level associated with lipolysis of adipose tissue have been found in the sick kids. A significant decrease in selenium, vitamin E and activity of glutathione peroxidase levels was observed in the kids with symptoms of muscular dystrophy. The activity of AST, CK and LDH was significantly higher in the animals with symptoms of the disease as well. Five isoenzymes were obtained in the electrophoretic separation of lactate dehydrogenase into isoenzymatic fractions in the muscle tissue. LDH4and LDH5 isoenzymes were dominating, and a significant increase in LDH5 fraction of the sick animals was also observed. Histopathological examination of muscle samples from sick animals revealed changes characteristic for the presence of Zenker necrosis.

Keywords: LDH isoenzymes; goat kids; nutritional muscular dystrophy; selenium deficiency.