| Summary |
In Taiwan, wide application of LPC vaccine resulted the high immunity in the sows. The offsprings therefore got the high titer of colostral antibody and the potency of LPC vaccination in these piglets was often interfered. In trying to avoid the interference of coiostral antibody by using the good LPC vaccine, piglets were vaccinated with a mixture of LPC and BVD antigens for this test.
The piglets aged 3 weeks in Tapu were vaccinated with LPC +BVD (NY, strain), LPC+BVD (VJGM strain) and LPC+BVD (Tobias strain) respectively and didn't show any bad reaction after vaccination. Seven weeks postvaccination, the vaccinated pigs were selected and sent to the laboratory for ALD challenge. They showed no or slight reaction and all survived. Most piglets possessed the colostral antibody titer of 1.21 or above before vaccination. After vaccination the antibody titer increased or decreased depend on the original level of coiostral antibody titer. After challenge, the production of antibody was rapid and most pigs reached the titer over 2. 68.
Before challenge, BVD antibody was low but increased to 2.21 two weeks postchallenge.
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