Comparing the vertical transmission of passive antibody from mother hen to chick among three chicken breeds after vaccination against Newcastle disease

Abstract

After inoculating Newcastle vaccine for chickens at 4 months-old, the blood samples were collected from the vaccinated hens at 7.5, 8.5 and 9.5 months-old, and from the chicks (of the vaccinated hens) at 1, 5, 10, 15 and 20 days old. In order to determine the protection rate and GMT index, HA and HI tests were applied. As a result, for the mother hens, the protection rate and GMT index gradually decreased by time and at the blood collection time (7.5, 8.5 months), the protection rate and GMT index were very high (protection rate was >85% and GMT index was >4.2) in all the chicken breeds. However, the protection rate and GMT index were low at the blood collection time (9.5 months), especially with the Yellow Chinese chicken breed, the protection rate was 73.33% and GMT index was 3.27; with the Luong Phuong chicken breed (the protection rate was 60% and GMT index was 2.8). For the chicks, the protection rate and GMT index also decreased generally by the blood sample collection time. In general, the chicks were only protected in the newborn day when the mother hens reached 7.5 and 8.5 months old. In conclusion, the vertical transmission of passive antibody depended on the level of antibody from the hens. The immune response and the vertical transmission of passive antibody in Luong Phuong chicken breed was lower than that of the Noi and yellow Chinese chicken breeds.