Anticoccidial effects of herbal extracts on Eimeria tenella infection in broiler chickens: in vitro and in vivo study.

Safe alternative anticoccidial drug to chemical feed additives are herbal extracts, because they don't results to tissue residue and drug resistance. In order to evaluate the effects of herbal extracts to control avian coccidiosis, 180 one-day-old broiler chickens were randomly divided into nine equal groups, as follows: (1) Biarum bovei (2) Nectaroscordum tripedale( 3) Dorema aucheri (4) Cichorium intybus (5) Prangos ferulaceae (6) diclazuril (7) Artemisia absinthium (8) infected control (9) uninfected control (each contains two groups). Administration of herbal extracts and supplementation of diclazuril was began 2 days before challenge and lasted for the duration of the experiment. The chicks of all the groups except uninfected control group were inoculated orally with sporulated oocysts (3 × 10(3) oocysts of Eimeria tenella) on the day 22 of age. The criteria employed were: body weight, feed conversion ratio, blood in feces, survival rate, lesion scoring, number of oocyst output per gram feces and histopathological changes. For histopathological evaluation, on day 12 post inoculation three birds from each group were randomly selected and humanly sacrificed. N. tripedale and diclazuril revealed better results in terms of growth performance, lesion score, extent of bloody diarrhea and oocyst count as compared to other herbal extracts. The increase in the severity of lesions was observed in groups of D. aucheri, A. absinthium, B. bovei, P. ferulaceae, C. intybus, diclazuril and N. tripedale, respectively. In conclusion, the current study showed that herbal extracts were effective in control of coccidiosis caused by the E. tenella infection.

Efficacy and transmissibility of Newcastle disease I-2 vaccine strain against a field isolate of virulent ND virus (JF820294.1) in village chicken.

This study was conducted to assess efficacy of heat-stable I-2 vaccine against Newcastle diseases in vaccinated and vaccinated in contact birds group following challenge against virulent Newcastle disease (ND) virus in village chicken. Also, to assess whether birds that have been exposed to vaccine virus-shedding, birds were protected against mortality and clinical signs after infection with a virulent strain of the ND virus (NDV). One hundred fifty one-day-old native chickens were divided into seven groups (4 experimental groups of 30 birds/group and 3 control groups (unvaccinated unchallenged, challenged, and just vaccinated). Birds in experimental groups were vaccinated either via drinking water or as food carrier with thermostable I-2 vaccine and then challenged with virulent isolate of NDV (JF820294.1), and eight birds were added as in-contact birds to vaccinated groups. Following challenge, seven extra birds were added to each group as in contact with vaccinated and challenged birds. Survival rate, clinical signs, necropsy finding, and mean antibody titer were evaluated in different experimental and control groups. Birds vaccinated via drinking water showed 100% survival rate. However, birds vaccinated with food carrier vaccine showed less than 50% survival rate. Based on the results obtained from this study, it can be recommended that I-2 vaccination via drinking water can effectively prevent ND in village chicken, since I-2 strain has been able to transmit to non-vaccinated-sensitive birds more effectively than velogenic NDV.

In vitro and in vivo susceptibility of Salmonella spp. isolated from broiler chickens.

Salmonellosis is the most important zoonotic disease, causing diarrhea and systemic infections. Due to poor management in antibiotic consumption, microbial resistance has increased in the treatment of zoonotic diseases. This study was conducted to evaluate the antimicrobial susceptibility of Salmonella spp. isolated from day-old broiler chickens which were referred to a private laboratory in Mazandaran-a province in the north of Iran-from 2008 to 2010. After harvesting the samples from the yolk sac, liver, and intestine of chickens, intestinal samples were transferred to selenite F and then incubated at 43 °C for 12-16 h. A loopful from selenite F and samples of liver and yolk sac were streaked on XLD and S.S agars. After incubation, the suspected colonies were inoculated into TSI agar for biochemical confirmation. The disk diffusion method on Muller Hinton agar was used to determine the susceptibility to antimicrobial agents. Because of the predominant use of enrofloxacin, sulfadiazine + trimethoprim, and flumequine for controlling Salmonella and Escherichia coli infections in the first week of broilers brooding in Iran, these three antibiotics were used in the in vivo study. From day 2 and continuing for 4 days, antibiotics were administrated in water, and after 10 days, samples from the liver, heart, and intestine were taken for isolation of Salmonella. In antimicrobial resistant tests, the most susceptible antibiotics were chloramphenicol, cefotaxime, and sulfadiazine + trimethoprim. The antimicrobial resistance to enrofloxacin, flumequine, colistin, and neomycin were 6.6, 11.6, 21.6, and 33.3 %, respectively. The results showed that 12 parties of broiler chickens were infected with paratyphoid salmonellae and the in vivo study showed that enrofloxacin and sulfadiazine + trimethoprim had the best and the weakest performance, respectively.