Effects of oral administration of levamisole on non-specific immunity, serum proteins and health in normal colostrum-fed neonatal dairy calves

Abstract

Soon after levamisole became widely used as a veterinary anthelmintic, it was recognised that concurrent enhancement of immune responsiveness sometimes accompanied anthelmintic treatment, especially in old or chronically ill animals. There are many reports concerning the immunomodulatory effects of levamisole in immunocompromised and vaccinated animals, but information about the effects of levamisole in immunocompetent animals is limited and controversial. Thirty Holstein dairy calves were randomly divided into two groups: test (n=15) and control (n=15). Blood samples were taken from the jugular vein, between 24 h and 48 h after birth, and put into EDTA-containing tubes and plain tubes; levamisole was then administrated orally at a dose of 2 mg/kg body weight three times at 1-day intervals in test groups. Blood sampling from all the calves was continued at days 7, 14, 21 and 28. The weight of calves was measured only at days 1 and 28 (before feeding). The levels of packed cell volume (PCV) (microhaematocrit), total white blood cells (WBCS) and differential leukocyte count (manual standard methods), total serum protein (colorimetry), beta and gamma globulins (electrophoresis), albumin:globulin (A:G) (calculated) and disease occurrence were measured and recorded. Appropriate statistical methods were used for data analysis, and P≤0.05 was considered as significant. No significant differences were seen for PCV, total serum protein, WBC count and health between groups. In the test group, neutrophil level at day 14 and monocyte level at day 21 were significantly higher than in the control group (P<0.05). Electrophoresis showed no significant differences for beta globulin level and A:G between groups, but gamma globulin level at day 28 was significantly higher in the test group (P<0.05).