In vitro efficacy of allicin on chicken Eimeria tenella sporozoites.

Chicken coccidiosis is a major parasitic disease caused by Eimeria spp. It is controlled and treated using chemical anticoccidial agents. Development of partial or complete resistance toward these anticoccidials is considered a major problem in poultry industry. Allicin is an organosulfur compound produced as a result of the reaction between alliin and alliinase after hacking of garlic. In this study, tenfold dilution from 180 mg/ml to 1.8 ng/ml of allicin in distilled water was tested against E. tenella in vitro. The percent of inhibition in allicin was from 99.9 to 71.53% using 180 mg/ml and 180 ng/ml, respectively. The percent of inhibition was 56.24% using 1.8 ng/ml. We used allicin as a treatment from plants against chicken coccidiosis; however, in vivo study should be performed to confirm these results.

Effect of dietary supplementation with oregano essential oil on performance of broilers after experimental infection with Eimeria tenella.

A study was carried out to examine the effect of dietary supplementation of oregano essential oil on performance of broiler chickens experimentally infected with Eimeria tenella at 14 days of age. A total of 120 day-old Cobb-500 chicks separated into 4 equal groups with three replicates each, were used in this study. Two groups, one infected with 5 x 10(4) sporulated oocysts of E. tenella and the other not, were given a basal diet and served as controls. The other two groups also infected with E. tenella were administered diets supplemented with oregano essential oil at a level of 300 mg/kg, or with the anticoccidial lasalocid at 75 mg/kg. Following this infection, survival rate, bloody diarrhoea and oocysts excretion as well as lesion score were determined. Throughout the experimental period of 42 days, body weight gain and feed intake were recorded weekly, and feed conversion ratios were calculated. Two weeks after the infection with E. tenella supplementation with dietary oregano oil resulted in body weight gains and feed conversion ratios not differing from the non-infected group, but higher than those of the infected control group and lower than those of the lasalocid group. These parameters correspond with the extent of bloody diarrhoea, survival rate, lesion score and oocyst numbers and indicated that oregano essential oil exerted an anticoccidial effect against E. tenella, which was, however, lower than that exhibited by lasalocid.

Comparison between effects of standard feed and whole wheat supplemented diet on experimental Eimeria tenella and Eimeria maxima infections in broiler chickens.

The effects of experimental infections with Eimeria tenella (Experiment 1, n = 144) or E. maxima (Experiment 2, n = 216) in broiler chickens fed whole wheat, with or without access to grit, as compared to a standard pelleted feed were studied. Inclusion of whole wheat was gradually increased up to 30% at 3 weeks of age. Grit was given separately. The chickens were kept on litter in a parasite-free environment with free access to water and feed. At 3 weeks of age half the number of chickens were individually inoculated with 500 sporulated oocysts of E. tenella (Experiment 1) or 3,000 sporulated oocysts of Eimeria maxima (Experiment 2), and the remaining birds were kept separate as uninfected controls. Neither coccidiostats nor growth enhancers were used. Oocyst concentration was determined from each group separately. Intestinal lesions were scored on 6 birds per feed regime 7 d postinoculation, and on the remaining birds at slaughter. Diet had no significant effect or bird performance during infection. However, there was an indication that the E. maxima infection had more negative effect on weight gain in birds given standard feed than in those given whole wheat supplement, but the difference was not significant (p < 0.09). The number of oocysts shed or mean intestinal lesion scores did not differ between diets in either experiment. In both experiments, the number of Clostridium perfringens was higher in the caeca of inoculated birds, but there were no differences between diets.

The effect of high n-3 fatty acids diets on the ultrastructural development of Eimeria tenella.

A study of development of Eimeria tenella in chickens fed high n-3 fatty acids (n-3FA) diets showed ultrastructural degeneration of both asexual and sexual parasite stages. Abnormal shedding of asexual and sexual parasite developmental stages into the cecal lumen was also observed. Ultrastructural degeneration was characterized by cytoplasmic vacuolization, chromatin condensation within the nucleus, a lack of parasitophorous vacuole delineation, and, in some cases, a complete loss of parasite ultrastructural organization. The results of this study indicate that diets high in n-3FA may be useful in the control of avian coccidia.

Eimeria tenella: genetic recombination of markers for precocious development and arprinocid resistance.

A mating was made between two populations of Eimeria tenella possessing the complementary traits of normal development (virulence) + resistance to the anticoccidial drug arprinocid or precocious development (attenuation) + drug-sensitivity. A small number of "recombinant" oocysts was recovered. The inheritance of markers from both parents into 22 cloned lines derived from the recombinant oocysts was confirmed by analyses of restriction fragment length polymorphisms of four repetitive DNA sequences.