Abstract:

This study was aimed to evaluate the levels of maternal immunity and to find the proper time for vaccination against infectious bursal disease (IBD) in broiler chicks with studying levels of total protein, albumin and globulin. One hundred twenty chicks were used and 20 of them were tasted respectively at age of 1, 7, 14, 21, 28, 35 days. It was observed that the levels of maternally derived antibody (MDA) were detectable up to 14 days of age and then declined to low levels in 21 days using ELISA test whereas globulin level did not show any significant change during the period of study. One hundred forty chicks were used to find the proper time of vaccination; they were divided in to seven groups, and vaccinated with live attenuated intermediate vaccine against IBD with different vaccination programs. The study showed that the second group which vaccinated 7 days and boostered at 14 days old was the best one. Ten chicks of each group were scarified at 28 days and 35 days for blood collection. It was demonstrated that the second group presented a significant elevation in levels of specific antibodies against IBD and globulin.

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