Coccidiosis: oocyst counting technique for coccidiostat evaluation.
TL;DR: Analysis of the counts obtained from 6 flocks of birds showed the frequency distribution of the number of oocysts counted per sample to be log-normal, thus permitting a comparison of the level of infection in different groups of birds.
About: This article is published in Experimental Parasitology.The article was published on 1970-08-01. It has received 135 citations till now. The article focuses on the topics: Flock.
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TL;DR: 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.
Abstract: 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 5·104 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 weigh...
317 citations
Cites methods from "Coccidiosis: oocyst counting techni..."
...Oocyst counts were determined using McMaster chambers and presented as the number of oocysts per g of excreta (Hodgson, 1970)....
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TL;DR: In the near future it is likely that more live vaccines based upon oocysts derived from attenuated strains of Eimeria will be developed but in the longer term vaccines will be based on the selective presentation to the host of specific molecules that can induce protective immunity.
258 citations
TL;DR: There is reciprocity between the immune status of chicken and their excretion of oocysts for each species, ensuring continual stimulation of immune responses in birds on litter, and Paracox vaccine, comprising all seven Eimeria species, is shown to stimulate immunity to each of them independently.
235 citations
TL;DR: Pure artemisinin appears to be effective against at least two coccidia species when used as a feed additive, and its activity may depend, in part, on the length of time it is administered before a challenge infection.
194 citations
Cites methods from "Coccidiosis: oocyst counting techni..."
...The total oocysts in each collection was determined from duplicate counts (McMasters chamber, Hodgson, 1970) of duplicate serially diluted aliquots of homogenates (total of four counts per homogenate)....
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TL;DR: It is concluded from this study that supplementation with mushroom and herb extracts resulted in enhancement of both cellular and humoral immune responses in E. tenella-infected chickens.
143 citations
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25 citations
TL;DR: The principle of long-term continuous drug administration for the prevention of coccidiosis is receiving wide attention, and it would seem of value to determine the factors which may account for its success or may limit its application.
Abstract: The chemotherapy of coccidiosis falls into at least two categories: (1) The control of mortality losses once a n outbreak has started. Drugs most likely to be of value for this purpose are those, such as the sulfonamides and nitrophenide* (Waletzky and Hughes, 1949), which act on the developmental stages of the parasites and may thus abort an otherwise fatal infection even several days after it has started. The “prophylactic” compounds, such as sulfur, the arsenicals (Goble, 1949), and the bisphenols (Johnson, et al., 1949), which act only on sporozoites, may reduce mortality if all of the birds have not yet ingested lethal doses of oocysts when drug administration starts. With any of these drugs, the dosage required to prevent mortality in the field is essentially the same as the dose required to prevent mortality in experimentally-induced infections in the laboratory. ( 2 ) T h e prevention of outbreaks. Drugs used for this purpose must be administered continuously for a long period of time. One of three assumptions may be involved in this method of handling coccidiosis: (a) full therapeutic doses are given in anticipation of fatal infections; (b) the drug is given in small doses which accumulate in the tissues to therapeutic levels by the time an outbreak occurs; or (c) less than therapeutic doses may suppress the early, light, subfatal infections sufficiently to prevent the build-up of lethal contaminations of oocysts in the litter, or prolong this period sufficiently to permit the birds to attain effective immunity before being exposed to otherwise fatal numbers of oocysts. Several drugs have been proposed for long-term continuous administration (nitrophenide and the bisphenols), but sulfaquinoxaline is the only one for which there are reported data on actual field experience. Since the principle of long-term continuous drug administration for the prevention of coccidiosis is receiving wide attention, it would seem of value to determine the factors which may account for its success or may limit its application. If sulfaquinoxaline is effective prophylactically a t less than therapeutic doses in infections with Eimeria tenella, then either assumption (b) or (c) may apply and (a) would be ruled out. Grumbles and Delaplane (1948) had the following experience in treating laboratory infections induced by the inoculation of 50,000 oocysts of Eimeria tenella with medication in the diet, starting 72 hours after inoculation and
23 citations
TL;DR: The successful control of coccidiosis by chemical feed additives has to a large extent made possible the mass production and confinement rearing of poultry as the authors know it today.
18 citations
TL;DR: The discovery that methyl 7-benzyloxy-6-n-butyl-4-oxo-1,4-dihydroquinoline-3-carboxylate has prophylactic activity against all six important species of coccidia and is more than ten times as active as any available alternative coccidiostat is reported.
Abstract: NINE species of coccidia are known to parasitize the domestic fowl. During the past 25 years a succession of drugs has made it possible to control coccidiosis to an increasing degree, but until recently no drug was known which would effectively suppress all species. Wide-spectrum prophylaxis has been most successfully accomplished by the use of mixtures such as amprolium + ethopabate + sulphaquinoxaline. We now report the discovery that methyl 7-benzyloxy-6-n-butyl-4-oxo-1,4-dihydroquinoline-3-carboxylate (I; R1 = CH3, R2 = n C4H9, R3 = C6H5·CH2·O) has prophylactic activity against all six important species of coccidia and is more than ten times as active as any available alternative coccidiostat.
11 citations