Patogenicidade e observações histopatológicas de frangos de corte infectados experimentalmente com isolados de Eimeria tenella, E. acervulina e E. maxima

Abstract

Cooccidiosis is one of the most important causes of economic losses within the poultry industry. The objective of this study was to evaluate the pathogenicity of E. tenella, E. acervulina, and E. maxima strains in commercial broilers chicks. Thirty nine commercial one day old broiler chicks, unvaccinated against coccidiosis, were used during this experiment. At day 14, chickens of G1 (n=10), G2 (n=10) and G3 (n=10) were infected with 2 x 10 4 sporulated oocysts of E. tenella, E. acervulina, and E. maxima respectively; G4 (n=9) served as the uninfected control group. All birds were sacrificed with 21 day old (seven days after infection). The prepatent period (PPP) for G1 and G3 was seven days, however, E. acervulina (G2) had a PPP of five days. No statistical differences were observed when the average weight gain (G1=182.7±63.4; G2=145.2±51.0; G3=183.3±56.8; and G4=211.5±89.0, p>0.10) of the evaluated groups was compared. Average of lesion scores were determined G1 (1.3±0.48, scores 1(n=7) and 2(n=3)), G2 (0.4±0.52, scores 0(n=6), 1(n=4)), and G3 (1.1±0.99, scores 0(n=4), 1(n=1) and 2(n=5)). Chickens from the infected groups (G1, G2 and G4) did not demonstrate a lesion score above 2. The histopathological lesions induced by these strains were consistent with those described for infection by Eimeria spp.

Immunological and histopathological evaluation of Eimeria tenella oocysts Egyptian local isolate vaccine and its comparative efficacy with a commercial live vaccine

“…G4 revealed infection by different coccidial schizonts, macrogametes and microgametes. These results agree with Zulpo et al (2007) in the presence of different stages of the parasite life cycle, villous atrophy, and severe inflammation in group infected with 2 x 10 4 sporulated oocysts of E. tenella.…”

Metabolic alterations in broiler chickens experimentally infected with sporulated oocysts of Eimeria maxima

“…The edema observed may be due to the inflammatory process and to the dilation of the submucosa and proliferation of epithelium cells in the acute phase of the disease. Similar results were observed by Zulpo et al (2007) when inoculating 2 × 10 4 sporulated oocysts of E. maxima, which resulted in edema, as well as dilation of the submucosa and proliferation of the epithelium cells. According to Montagne et al (2003), an increase in the villus-to-crypt ratio corresponds to an increase in digestion and absorption.…”

“…However, the mean weight gains of the control group were always greater than those of the infected group during the experimental period. Equivalent results were found by Zulpo et al (2007), who did not obtain any significant differences in weight gain, but the means were always lower for the infected group.…”

“…Similar results were also obtained by Gabriel et al (2003) using dosages of 5 × 10 3 and 5 × 10 4 of sporulated oocysts of E. maxima, in which the birds that were subjected to the greater challenge presented lower weight gain than shown by the birds with the smaller challenge. Zulpo et al (2007) also reported lower weight gain among birds infected by E. maxima, when using a dosage of 2 × 10 4 .…”

Oocysts Output of Broilers Experimentally Infected with Eimeria tenella And Treated with N- Butanol Leaf Extract of Khaya senegalensis

“…Anticoccidial drugs have been in use for more than 50 years and presently almost all commercial broilers are reared with the agents in their feeds (Chandrakesan et al, 2009). The development of drug-resistant field strains and the necessity for withdrawal period for these drugs prior to slaughter prompted the exploitation of alternative methods for controlling coccidiosis (Zulpo et al, 2007). There is an increasing use of medicinal plants and plant products as alternatives to orthodox medicine especially in developing nations (Mikail et al, 2007).…”