Immune response to Newcastle disease virus in broilers: a useful model for the assessment of detoxification of ervil seeds

Ervil (Vicia ervilia) seeds are produced in the Mediterranean region and used as a source of protein for cattle and poultry. The methods used to assess the toxic effects of legume seeds in the feed of poultry include the observation of one or more parameters, including abnormal signs, weight gain, feed consumption, gall bladder weight, pancreas weight, pancreas proteolytic and amylase activity, haemolysis of red blood cells, liver weight, liver glutathione level, liver and plasma lipid levels, and plasma lipid peroxide levels. The authors describe the use of quantitative determination of the immune response to Newcastle disease virus (NDV) vaccine in broilers as a model that can be used to assess different detoxification treatments of ervil seeds. Broiler chicks fed differently-treated ervil, supplemented as 25% of the diet, at one to four weeks of age and vaccinated intraocularly with live NDV vaccine at eight days of age, showed different immune responses at three weeks post vaccination. Immunosuppression with regards to NDV was apparent in the group of birds raised on untreated ervil supplement, resulting in a mean immune response (titre) of 798.5. Five of the six different treatments of ervil seeds resulted in different degrees of rectification of the immunosuppression, with some broilers reaching a mean NDV immune titre of 2070.6, similar to that obtained in control broilers raised on a basal diet with no ervil seed supplement (mean NDV immune titre of 2333.8; P > 0.05). The five successful treatments of ervil (in increasing order of rectification of immunosuppression in broilers, with mean NDV titres in parentheses) were: ground soaked dried ervil (971.6), ground autoclaved dried ervil (1223.1), soaked autoclaved dried ervil (1273.1), soaked dried ervil (1340.0), and ground-soaked autoclaved dried ervil (2070.6).