EFFECT OF VITAMIN-MINERAL PREMIX ON IMMUNE RESPONSE OF BABY CHICK RANIKHET DISEASE VACCINE IN CHICKS

Abstract

A total of 150 (75 broiler and 75 layer) apparently healthy chicks were used to investigate the effect of vitamin-mineral premix on immune responses of Newcastle disease (ND) vaccine (Baby Chick Ranikhet Disease Vaccine, F-strain) during the period from January to March 2003. The chicks were divided into six groups namely group A, B and C for broiler and group D, E and F for layer birds consisting of 25 birds in each group. Chicks of group A, C, D and F were supplied with vitamin-mineral premix containing feed and chicks of group B and E were supplied with vitamin-mineral deficient feed. The chicks of group A, B, D and E were primarily vaccinated with 0. 1 ml of BCRDV of 1065 EID50/0. 1 ml per bird through intraocular route at the age of day 3 and were revaccinated with the same vaccine at the age of day 17. Birds of group C and F were kept as unvaccinated control. Chickens of all the groups were challenged with the virulent isolate of NDV @ 0.5 ml/bird IM (1045 EID50/0.1 ml) after two weeks of secondary vaccination. Titres were determined before and after vaccination by hemagglutination test (HI) test and serum neutralization test (SNT) was performed to measure the potency of immune serum. The HI titres of birds of groups A, B, D and E were 128, 16, 128 and 128 respectively after primary vaccination and 256, 128, 256 and 256 respectively after secondary vaccination. From the study it was found that among the experimental layer birds, no difference was noticed on the immune response to BCRDV. On the other hand, among the experimental broiler birds, birds of group A revealed higher HI titre compared to the birds of group B. Results of serum neutralization test indicated that the sera of birds possessing HI titre ?128 demonstrated a good level of virus neutralizing activity of ?7.60. The birds possessing HI titre of 128 ± 0.00 did not show any clinical signs of ND following challenge and the survivability was recorded as 100%. It may be concluded that supplementation of vitamin-mineral premix to the diet induces better immune response following vaccination with BCRDV in broiler chickens compared to the layer chickens.