Abstract

Objective: The objective of this study was to evaluate some hematological parameters in commercial layers inoculated with two virulent Pasteurella multocida serotypes.
Materials and Methods: A total of 84 twenty-week-old black Harco layers were randomly assigned to seven groups (A, B, C, D, E, F and G) with 12 birds per group. 1mLof live attenuated fowl cholera (FC) vaccine was administered subcutaneously at 24 weeks of age to groups A and B, emulsified inactivated (killed) FC vaccine was administered dosed at 0.5 mL per bird subcutaneously at 24 weeks of age to groups C and D, groups E and F were not vaccinated, while group G served as control. Groups A, C and E were inoculated with P. multocida serotype A:1 and groups B, D and F were inoculated with P. multocida serotype A:3. Using McFarland Standard, each bird received a dose of 0.5 mL (0.1 mL intranasally and 0.4 mL intramuscularly) containing 4.5 x 108 cfu/bird.
Results: For PCV (P≤0.2692 and P≤0.7643) and HB (P≤0.2806 and P≤0.7266) on day 2 and 10 post inoculation, there was no significant difference between the vaccinated, non-vaccinated groups and control group G. However, there was a highly significant difference P≤0.05 in the mean concentrations of ALP between the control group G (67.67±1.453 u/l) vaccinated groups A (80.33±4.98 u/l), B (81.33±2.60 u/l), C (75±6.35 u/l), and D (84±5.132 u/l) and unvaccinated groups E (104±1.528 u/l ), and F (78 ±3.512 u/l) post inoculation.
Conclusion The PCV significantly decrease P≤0.05 in layers vaccinated and inoculated with P. multocida but increase in unvaccinated layers inoculated P. multocida. The mean serum ALP concentration significantly increase P≤0.05 in unvaccinated layers inoculated with P. multocida when compared to layers vaccinated and inoculated with P. multocida.

Key words: Fowl cholera; P. multocida; Layers; Serotype; PCV; HB; ALT; AST; ALP