Study of Cell-Mediated Immune Response in Experimental Aflatoxicosis of Buffalo Calves

  • B. B. Khadka Department of Livestock Services, Harihar Bhawan, Kathmandu, Nepal
  • B. K. Sinha Department of Veterinary Microbiology, Bihar Veterinary College, Patna- 14, India

Abstract

Humoral immune response due to the B-lymphocytes and cell-mediated immune response (CMIR) due toT-lymphocytes are the two arms of immune response. This study was undertaken to investigate CMIR in buffalo calves with experimental aflatoxicosis. Six buffalo calves were randomly divided into two groups of three animals each. One group was fed aflatoxin B1 (AFB1) at the rate of 10 mg / kg body weight daily for 30 days (treatment group) while the other group was left as control. CMIR in both treated and control calves was studied by erythrocyte (E) rosette technique as well as the delayed type hypersensitivity (DTH) skin test. T-lymphocytes status in these animals before and at 10 days intervals after experimental aflatoxicosis was studied by using E - rosette technique. The mean percent E-rosette in control calves remained unchanged throughout the experiment (i.e. day 0, 10, 20 and 30) whereas it increased in AFB1 intoxicated animals on day 0 and 10 and decreased thereafter. DTH skin test, carried out by initial sensitisation at day 20 followed by challenge on day 30 post-intoxication by BCG vaccine antigen. It revealed an increase in mean skin thickness from 3.43+0.12 mm pre-challenge to 10.50+0.75 mm 48 hr post challenge in control calves as against 3.57k0.37 mm to 4.57k0.32 mm in treated calves. There was a highly significant (P<0.01) reduction in skin thickness in AFBl intoxicated calves when compared with the controls. These findings provided evidence of CMIR suppression inAFB1 intoxicated buffalo calves.