Comparison between phytochemical pentadecylphenol and anticoccidial vaccine in performance, oxidation, inflammation and surface antigen activity of broilers

Abstract

Abstract The present study aimed to compare the effects of phytochemical pentadecylphenol (PDP) and anticoccidial vaccine on performance, oxidation, inflammation and surface antigen (SAG) activity of broilers. In Experiment 1, 5 treatments with 6 replicates were carried out, consisting of a negative control (NC), vaccination (VAC) with live Eimeria tenella ( E. tenella) vaccine at 1 day of age, and addition of PDP at concentrations of 0.05, 0.10 or 0.20 g/kg feed, respectively, with a total of 600 broiler chicks aged 1 to 21 d. In Experiment 2, 12 birds per replicate from the NC, VAC and PDP treatments were randomly selected after 21 d to establish an E. tenella infection model. The new treatments were positive control (PC) from NC, VAC + infection (VACi), and PDP + infection (PDPi), respectively. All birds received the same diets from 22 to 28 d as in Experiment 1. Birds in treatment PDP had a growth performance similar to those in NC, whereas birds in VAC had lower (p < 0.05) body weight gain. Serum oxidative markers (diamine oxidase, malondialdehyde) and cytokines (interleukin 3, interferon γ) were decreased (p < 0.05) in PDP but increased (p < 0.05) in VAC, indicating that the chronic oxidative and inflammatory status contributes to the negative effect of the vaccine. Results in Experiment II showed that both VAC and PDP protected against coccidiosis by reducing (p < 0.05) oocysts shedding, intestine damage, and bird mortality. Furthermore, in contrast with PC, birds in PDPi and VACi had lower (p < 0.05) transcriptional levels of SAGs (1, 2, 5, 9, 10) but a greater (p < 0.05) SAG4. The dose analysis of PDP showed that 0.10 g/kg was more suitable in growth enhancement and coccidial control. It is concluded that dietary PDP has a anticoccidial efficacy comparable with vaccines and is involved in regulating transcriptional profiles of E. tenella SAGs.