Immune response to ranikhet disease vaccine in japanese quails (Coturnix coturnix japonica) fed chemically treated rapeseed meal
Rapeseed meal (RSM), a rich source of protein, is sparingly utilized in poultry rations primarily due to the presence of several toxicants mainly the glucosinolates (GSLs). The present study compared the suitability of commercially available solvent extracted RSM, before and after treatment with mineral salts for growing Japanese quails (Coturnix coturnix japonica) in terms of immunocompetence. Treatment of RSM with copper (Cu) or ferrous (Fe) salts singly or together reduced the GSLs contents drastically from 119.7 to 59, 56 and 51.8 μmolGSL/g, respectively. Ranikhet disease (RD) vaccine response of 60 growing meat type quails, randomly distributed to 5 lots of 12 each, maintained on 15% raw and treated RSM diets, was evaluated. Diets D1 to D5 contained, respectively, soybean meal (SBM), raw RSM, RSM-Cu, RSM-Fe and RSM-Cu+Fe, and were offered separately ad lib to quails. On 15th and 30th day post vaccination (DPV), serum samples were tested by haemagglutination inhibition (HI) test for RD-HI antibody titre for evaluation of humoral immune response. Simultaneously, cell mediated immune response was assessed by leukocyte migration inhibition test (LMIT) of the peripheral blood leukocytes. The results revealed a significantly (P<0.05) higher RD-HI antibody titre for quails in group D3, D4 and D5 (4.93±0.15, 4.85±0.13 and 5.02±0.11, respectively) than in group D1 (4.42±0.12) and/or D2 (4.33+0.11) on 15th DPV. Almost a similar trend was observed on 30th DPV, although, the titres tended to decrease. Quails of dietary group D5 responded significantly (P<0.05) with a highest value of 41.15±0.87% LMI as compared to those of 39.51±0.66, 37.18±0.85, 34.76±1.33 and 32.89±1.12 for diets D3, D4, D1 and D2, respectively, at 15th DPV. The LMI percentage tested at 30th DPV gave significantly (P<0.05) higher values of 50.41±1.18, 48.65±1.14 and 51.19±0.8 for diets D3, D4, and D5, respectively, than for diet D1 (44.68±0.69) and D2 (41.26±0.83). The results of HI and LMIT are in agreement of each other and the immunocompetence generated with different diets in descending order was rated as D5>D3>D4>D1>D2. In conclusion, mineral treated RSM diets clearly demonstrated better immunological responses of quails compared to those fed the raw RSM or SBM, and thus the treated RSM upto 15% could well be used in quail rations as a good protein source.