A field study in commercial layers to evaluate the effects of an HVT-IBD vector vaccine on production performances in comparison with a live IBD vaccine

DEVAUD lsabelle, HERIN Jean-Bernard, TROTEL Anne, PAGOT Eric, VOISIN Florian



The objective of the field trial was to evaluate, by a blind positive-controlled study, the effects of vaccination with an HVT-IBD vector vaccine (VAXITEK® HVT +IBD - MERIAL) on a commercial farm in comparison with a conventional infectious bursal disease live vaccine. Two groups of 250 day-old brown pullets each, were set at the hatchery. One group received the vector vaccine at day-old by subcutaneous injection at the hatchery (test group); the other group was vaccinated on farm by drinking water with a classical Gumboro intermediate strain vaccine at 3 and 4 weeks of age (control group). Bath groups were reared in the same pullet house and were then kept in cages in the same industrial laying house. Targeted parameters were: body weight evolution and its homogeneity during the rearing phase; egg laying rate and egg quality during the laying period. A serological monitoring was implemented to evaluate the antibody response against classical vaccinations and viral infections of layers. As compared to the control group, in the test group an improvement in severa! production performances was observed as follows: body weight evolution during the 15 weeks of rearing {p=0.0022), body weight on week 10 {931.7 g vs 905.2 g, p<0.001) and on week 15 {1323 g vs 1303 g, p=0.023), average laying rate {89.07 % vs 87.89 %), 3.88 extra marketable eggs in 47 weeks of lay (table 1) (p<0.001), average egg weight (63.6 g vs 62.4 g, p<0.001), Haugh units (89.56 U vs 88.59 U, p=0.012) and breaking strength (38.845 N vs 38.075 N, p=0.022) during the laying period. Global serological response against Gumboro disease, infectious bronchitis, Newcastle disease and avian pneumovirus infections was not significantly impaired whatever the group, however it was more homogenous against Gumboro disease in the test group.