Anticoccidial vaccine effect on physiological and immunological parameters in broiler chickens.

The effect of an anticoccidial vaccine on broiler chickens challenged at 21st day of age with 6.0 x 104 E. acervulina: 5.0 x 103 E. maxima: and 4.0 x 104 E. tenella sporulated oocysts/bird, was evaluated. Four groups of 20 chicks each, one day old, were randomly assigned to: 1) unvaccinated, unchallenged control (UUC); 2) unvaccinated, challenged control (UCC): 3) vaccinated, challenged (VC); and 4) vaccinated, unchallenged (VU). All birds were weekly weighed. At 7 days post challenged (PC), weight gain % (WG), intestinal pH (IpH), gut weight (GW), intestinal IgA concentration (IgAC), gut lesion score (GLS), oocyst output (OO) and percentage of specific coccidia species (SCS) in feces were recorded. At 14 and 26 days, gastrointestinal passage time (GPT) was measured. At 21 days of age, body weight from groups VC (544.8 ± 105) and VU (504.9 ± 88) were lower (P < 0.05) than group UUC (615.6 ± 100) At 28 days, group UUC was the heaviest (923.3 ± 126), and with the highest WG (49.97%). Group UCC had the lowest WG (24.60%), and at 26 days, it had the lowest GSF (212.4 ± 311, different (P < 0.05) from group VU with 43.81% of WG and 158.4 ± 52 for GSF. Both, IpH and GW did not differ among groups. The lowest IgAC was seen in ceca from group UUC. Group UCC had the highest GLS, whereas groups UUC and VU had the lowest GLS. Group VC showed higher GL5 for E. maxima and E. tenella than groups UUC and VU. At 28 days, group UCC elicit higher OO; however, group VC showed higher OO than groups UUC and VU. At 7th day PC, the E. acervulina SAC for group VC was lower than groups UCC and VU, even though E. maxima and E. tenella SAC s for this group (VC) had increased. Molecular characterization for field strains and their comparison with commercial vaccines must be held forward to understanding antigenic differences. [ABSTRACT FROM AUTHOR]