2.4. Cell mediated immune response
The cell mediated immune (CMI) response was assessed in the kids after 170 days of experimental feeding by in vivodelayed type hypersensitivity (DTH) reaction by measuring the increase in skin thickness (Kim et al., 2000) in response tointra-dermal inoculation of phytohaemaglutinin-p (PHA-p). The skin on both the sides of the neck was shaved with the help of a razor and injected with 25 g of PHA-p in 100 L of PBS (pH 7.4) at two different sites 4 cm apart from each other on one side of neck and 200 L of PBS at two different sites 4 cm apart on other side of the neck as a control. The skin thickness/induration was measured at 0, 12, 24, 48, 72 and 96 h post sensitization with the help of a vernier calliper. All the injections and skin measurements were made by the same person to minimize the variations.