Control of bovine coccidiosis with monensin: in nonresistant newborn calves

Newborn Holstein male calves were purchased within 3 days after birth and were removed from the local farms to the Dixon Springs Agricultural Research Center. They were hand-fed for 7 weeks and then weaned to a prepared feed. Eight groups, each of 4 calves, were housed in separate pens. In each of 4 pens (pens 2 to 5), 1 calf was inoculated with sporulated oocysts of Eimeria bovis (and was not medicated); 1 calf was inoculated and given feed with added monensin at the dosage level of 10 g/906 kg of feed; and 2 calves were inoculated and given medicated feed with added monensin at the dosage level of 20 g/906 kg or 30 g/906 kg. In the 4 other pens (6 to 9), the calves were inoculated with E zuernii and otherwise were given feed without or with added monensin as in pens 2 through 5. Another group of 5 calves (all kept in 1 pen), served as noninoculated, nonmedicated controls. At 14 days after inoculations with E bovis, the single calves in each of the 4 pens that were given the nonmedicated feed began to show clinical signs of coccidiosis and discharged increasing numbers of oocysts. The other inoculated calves (given monensin) had fewer clinical signs and discharged fewer oocysts in the feces as the level of medication in the feed increased. The calves inoculated with E zuernii developed only moderately severe infections when compared with those inoculated with E bovis. Inoculated (with E bovis) nonmedicated calves had severe reductions in feed consumption and weight, and 3 of 4 died.(ABSTRACT TRUNCATED AT 250 WORDS)     

Neuropathogenicity of Equine Herpesvirus 9 in Cattle

The pathogenicity of equine herpesvirus 9 (EHV-9), a neurotropic equine herpesvirus isolated from a herd of Gazella thomsoni, was studied in cattle. Seven calves were inoculated intranasally with 10⁵ and 10⁷ plaque-forming units of the EHV-9 P19. Three animals showed brain lesions consisting of glial reactions and perivascular cuffings in the olfactory bulb and the frontal and temporal lobes. Additionally, the animal that was inoculated with 10⁷ plaque-forming units showed neuronal degeneration and loss, as well as nuclear inclusions compatible with herpesvirus. EHV-9 was isolated from the brain of calf 6 and the lungs of calves 1 and 2. The results suggested that cattle are susceptible to experimental infection with EHV-9 and at risk from natural infection from reservoir hosts.     

Administration of Bacillus coagulans in calves: recovery from faecal samples and evaluation of functional aspects of spores

An investigation was carried out into the recovery from calf faeces of Bacillus coagulans spores added to the feed as probiotic. For this purpose, Bacillus coagulans spores (9 log₁₀ CFU g^?1) were given daily to 10 calves during the whole farming periods; another 10 calves acted as controls. Throughout the trial the faecal spore counts were significantly (P?<?0.01) higher in the treated group than in the controls (averaging 2.1?×?10⁵ vs 3.7?×?10⁴?CFU g^?1). Bacterial cells were recovered from faecal samples and ribotyping matched the strain isolated from faecal sample to the clone administered to the animals. In addition, the recovered cells were found to maintain their functionality aspects of acid production, survival in artificial gastric juice and in the presence of bile, and attachment to human intestinal epithelial cells. The results further elucidate the fate of spore formers administered to calves, and this will help in the development of new species-specific nutritional strategies.     

Effects of inoculations with Eimeria zuernii on young calves treated with decoquinate or narasin with or without dexamethasone

Sixteen 7-week-old Holstein male calves were inoculated with sporulated oocysts of Eimeria zuernii. Four calves (controls) were euthanatized and necropsied at 14 and 20 days after inoculation (DAI). Two calves were treated with 20 mg of dexamethasone (IM) on 13, 14, and 15 DAI and euthanatized and necropsied 17 DAI and 2 calves were given similar treatments and necropsied 20 DAI. The 8 other calves were euthanatized and necropsied 20 DAI. Two were started on the anticoccidial drug decoquinate in feed 13 DAI; 2 others were given decoquinate on the same schedule plus dexamethasone on 13,14, and 15 DAI. Two calves were given the antibiotic narasin in feed beginning 13 DAI and 2 calves were given parasin on the same schedule plus dexamethasone on 13,14, and 15 DAI. All calves, except 2 controls necropsied 14 DAI and 4 calves given decoquinate, discharged moderate-to-large numbers of oocysts in feces and had moderate-to-serve changes in fecal consistency. Histologic examinations revealed large numbers of endogenous stages in tissues of calves treated or not treated with dexamethasone. Few endogenous stages were observed in tissues from calves that were given decoquinate or decoquinate plus dexamethasone. Calves given narasin or narasin plus dexamethasone had moderate-to-large numbers of endogenous stages in the tissues.     

Distribution of cysts and tachyczoites in calves and pregnant cows inoculated with toxoplasma gondii oocysts

Sixteen calves and 6 cows were each inoculated with 100 000 infective oocytes of the GT-1 strain of Toxoplasma gondii. Cattle were necropsied between 3 and 287 days post-inoculation (DPI) and their tissues were inoculated into mice or fed to Toxoplasma-free cats for the detection of Toxoplasma in bovine tissues. Ten to 10 000-fold more T. gondii were recovered from small intestine and mesenteric lymph nodes of calves at 3 and 6 DPI than from lungs and liver, and the number of T. gondii in bovine tissues was reduced 1000-fold between 6 and 8 DPI. By using the pepsin digestion technique, or feeding tissues to Toxoplasma-free cats, it was demonstrated that T. gondii encysted in bovine tissues as early as 11 DPI and persisted as late as 287 DPI. More Toxoplasma gondii cysts occurred in livers than in any other bovine tissue. Of the 6 cows inoculated at 95–155 days after breeding, 5 delivered normal calves and T. gondii was isolated from only one of these calves. One cow was barren. Toxoplasma gondii was not isolated either by mouse inoculation or by feeding cats tissues from 2 cows killed 132 and 190 DPI. Toxoplasma gondii was not isolated in mice inoculated with tissues of cows killed 98 and 109 DPI, but cats fed on bovine tissues shed T. gondii oocysts. The organism, however, was isolated in mice inoculated with the mesenteric lymph nodes of 1 of the 2 cows killed 162 and 168 DPI, and from the small intestine of the other. Cats fed tissues of these cows later shed T. gondii oocysts.     

The prepatent and patent periods of Eimeria alabamensis and further description of the exogenous stages

Eimeria alabamensis infections were established in calves 5 to 6 weeks of age by adminestering 10 million, 80 million, or 100 million sporulated oocysts. The prepatent period was 6 to 8 days (mean 6.6). Oocyst discharges usually lasted for 2 to 3 days although a few calves passed oocysts throughout the rest of the 3-week observation period. Calves with oocyst discharge exceeding 1 million oocysts per g of feces had a moderate diarrhea at the time of peak oocyst discharge. No other clinical signs were observed in any of the infected calves. Reinoculations with 100 million sporulated oocysts given 3 weeks after the initial inoculations of 10 million or 80 million oocysts resulted in infections characterized by greatly reduced oocyst discharges. Sporulated oocysts of E. alabamensis were 16 to 24 μ by 12 to 16 μ and were usually ovoid. The oocyst wals consisted of two layers. Sporocysts were elongate-ellipsoid, had a distinct Stieda body, and were 10 to 12 μ by 4 to 6 μ. Completely sporulated oocysts were first observed after 5 days at 25 °C, and most were sporulated after 8 days. Oocysts did not sporulate at 4 °C, 33 °C, and 37 °C.     

Neurological disorders,virus persistence and hypomyelination in calves due to intra‐uterine infections with bovine virus diarrhoea virus

The clinical and pathological findings after a natural intra‐uterine infection with BVD‐virus in a Friesian dairy herd are described. The virological and serological aspects will be discussed in a separate paper (30).

In a period of 4 years, 11 calves were hum with the following nervous symptoms: more or less serious incoördination, tremor, oscillating nystagmus, and a negative blinking reflex. The pupillary and sucking reflexe's were normal. No ocular defects, such as lenticular opacity or retinal atrophy were observed.

The first calf was born in 1979. Within 6 months the symptoms disappeared. After a normal conception and pregnancy this animal gave bⁱrth to 2 clinically normal calves in 1981 and 1982. The second calf died at the age of 2 months, due to an ulcerating enteritis.

In 1980, again 8 calves with the same nervous symptoms were born within a period of 3 months. Two calves died at the age of 3 days and 5 weeks respectively; 2 calves were sold when 10 days and 3 weeks old; one calf did not improve and was necropsied at the age of 17 days. The remaining 3 calves showed only a slight hypermetria when examined after 6 months. At that time nystagmus was only visible with ophthalmoscopy. Two calves were slaughtered when 10 months old. The last one, a bull, proved to be sterile and was necropsied at the age of 1 ½> year.

A calf, born in 1981, recovered within a week and was necropsied at the age of 15 days. The last calf, born in 1982, did not improve at all and was necropsied at the age of 14 days.

During these 4 years none of the other animals in the herd showed any symptoms due to an acute or chronic BVD‐virus infection.

At post mortem examination of 6 animals no macroscopically visible malformations were found. Hypomyelination and abnormal glial cells were evident in 5 cases, especially in the two youngest calves which did not show any improvement. One of them had an obvious thymic hypoplasia. The calf which recovered within a week showed only very slight changes. In one of the calves slaughtered at 10 months, inflammatory lesions were found in the brain. The diagnosis was confirmed by virological investigations.

Clinically as well as pathologically there was a close resemblance to Border disease in lambs and congenital tremor in piglets after prenatal exposure to Hog cholera virus.     

Effect of resinous extract from Commiphora swynnertonii (Burrt) on experimental coccidial infection in chickens

A crude resinous extract from Commiphora swynnertonii was tested against an experimental coccidial infection in local chickens. A total of 80 growing chickens were randomly assigned into five groups, which received different treatments. Chickens in G1 were not infected with coccidian oocysts and therefore served as a negative control. All chickens in G2, G3, G4 and G5 were infected through oral administration of coccidian oocysts suspension at a dosed rate of 1.5?×?10⁴ Eimeria spp. oocysts per bird. Starting from day 3 post-infection (p.i), chickens in different groups were treated for 7 consecutive days as follows: G1 and G2 (positive control) received 5 ml of normal saline as placebo, G3 and G4 were given the extract at 400 and 800 mg/kg bodyweight whereas G5 received anticoccidial drug. Clinical signs, bodyweights, oocysts counts and mortality rates were observed regularly. Results showed that oral administration of the resinous extract to chickens with coccidiosis significantly reduced mortality rate from 94 to 25 % and oocysts counts from 1.03?×?10⁵ to 6.55?×?10³ oocysts/g faeces (p?<?0.05). Also a body condition score chart indicated less severe clinical signs of the disease in the groups which received the extract. Mean daily body weights were slightly reduced by the administration of the extract but this effect disappeared by day 7 p.i. These findings clearly indicate that resinous extract from C. swynnertonii has significant anticoccidial effect against experimental Eimeria spp. infection in chickens. A larger field trial to validate the use of the extract in chickens naturally infected with Eimeria spp. is required.     

鸡巨型艾美耳球虫单卵囊分离及雏鸡扩增试验

采用饱和食盐水漂浮法收集就诊病死球虫阳性鸡小肠中段内容物中的球虫卵囊,恒温培养至孢子化后,用2%琼脂薄板进行球虫单卵囊分离,分别感染7只5日龄雏鸡,对据形态学鉴定为巨型艾美耳球虫的分离株进行2代单卵囊分离和雏鸡感染,取其后代以每只1.0×10⁴个卵囊感染10只10日龄雏鸡进行卵囊扩增,获得大量纯种巨型艾美耳球虫卵囊。结果表明,刀片切割琼脂薄板单卵囊分离法操作简便,单卵囊感染成功率较高,准确率达100%,适用于纯种卵囊的分离与扩增。     

Eimeria tenella in chickens: Studies on resistance to the anticoccidial drugs monensin and lasalocid

The response of the Houghton strain of E. tenella to monensin and lasalocid is described. Neither drug was able to completely control this strain at 125 ppm. At this concentration oocyst production was not completely suppressed by monensin in birds given ten oocysts. At higher concentrations both drugs were able to control E. tenella (H) in birds given 1 × 10⁵ oocysts but monensin was toxic. 375 ppm monensin did not prevent oocyst production in birds given 4 × 10⁶ oocysts. Resistance could not be developd to either of these compounds after 12 serial passages in the presence of drug. Serial passage of E. tenella (H) in the presence of monensin however resulted in an increase in pathogenecity. This greater pathogenecity was not due to a better ability to multiply in the host.     

Resistance to Eimeria zuernii produced after chemotherapy of experimental infection in calves

Nineteen Holstein-Friesian bull calves were inoculated with 2.4 × 10⁶ sporocysts of Eimeria zuernii by stomach tube. The calves were divided into three groups 10 days after infection. The first group (seven calves) was treated with monensin (1 mg/kg body weight daily) from the 10th–20th day after infection; the second group (six calves) with amprolium (10 mg/kg body weight daily) for the same period of time and the third group (six calves) acted as infected controls. Both drugs were effective in preventing clinical signs, in reducing rates of weight gain and in suppressing oocyst production. The calves were reinfected with E. zuernii 35 days after the initial infection. The calves of all three groups were resistant to the second infection with E. zuernii as measured by rates of weight gain, fecal oocyst output and lack of clinical signs.     

Effect of infection with mixed Eimeria species on T cells and T regulatory cell properties

An experiment was conducted to study the effect of a mixed Eimeria infection on chicken regulatory T cell (Treg) percentages, T-cell percentages, cell proliferation, and cytokine mRNA amounts. Specific-pathogen-free white leghorn birds were raised in battery cages and were challenged with and without coccidial oocysts at 21 d of age. At 6 d post challenge, birds inoculated with coccidial oocysts shed an average of 1.5 × 10⁴ oocysts/gram of feces. At d 6 post challenge, both CD4⁺ and CD8⁺ cell percentages in the cecal tonsil were significantly (P < 0.01) increased in challenged birds compared to the control. At d 11, CD4⁺ cell percentages in the cecal tonsil were higher in the control birds. At 6 d post challenge there was a 6-fold increase (P = 0.18) in IL-10 mRNA content in the cecal tonsils of infected birds compared to the control. At 11 d post challenge there was a 4-fold increase (P = 0.09) in IL-10 mRNA content in the infected birds’ cecal tonsils. At 11 d post challenge there was half as much (P = 0.10) IFN-γ mRNA content in the spleen of infected birds compared to the control. At 6 d post challenge, the CD25 depleted cecal tonsils of infected birds had increased proliferation (P < 0.05) compared to the control. It could be concluded that a mixed Eimeria infection causes an up-regulation of IL-10, Tregs, and CD4⁺ cells in the cecal tonsils during the late stages of infection.     

Infectivity and persistence of an outbreak strain of Salmonella enterica serotype Typhimurium DT160 for house sparrows (Passer domesticus) in New Zealand

AIM: To examine the infective dose, incubation period and disease progression of an isolate of Salmonella enterica serotype Typhimurium definitive type 160 (DT160) originating from a naturally-infected house sparrow (Passer domesticus) during an outbreak of the disease in New Zealand.

METHODS: Thirty-six house sparrows captured from the wild and free of Salmonella spp were divided into six groups of six birds, housed individually, and inoculated orally with phosphate buffered saline (PBS) or 10¹, 10², 10³, 10⁵, 2 × 10⁸ colony forming units (cfu) of the outbreak strain of S. Typhimurium DT160. The birds were observed for 10 days for clinical signs and/or mortality, and faecal samples were collected to determine excretion of S. Typhimurium. The birds were eutha- nised 11 days post-inoculation (p.i.) and a wide range of tissue samples were collected for histopathological examination, and culture and typing of Salmonella spp. Macro-restriction profiling by pulsed-field gel electrophoresis (PFGE) using XbaI was performed for the epidemiological typing of S. Typhimurium DT160 isolates.

RESULTS: Mortality in house sparrows inoculated with S. Typhimurium DT160 was dose-dependent, and 2/6 birds inoculated with ¹⁰⁵ cfu and all six birds inoculated with 2 × 10⁸ cfu died during the study. Infected sparrows displayed few clinical signs, apart from diarrhoea and/or polyuria, fluffed plumage, and sitting on the floor of the cage. Faecal excretion of DT160 occurred briefly in two birds inoculated with 10² cfu and four birds inoculated with 10³ cfu, on most days in five birds inoculated with 10⁵ cfu, and continuously in six birds inoculated with 2 × 10⁸ cfu. DT160 was isolated from the livers of three birds which received 10³ cfu, five birds dosed with 10⁵ cfu, and all six birds given 2 × 10⁸ cfu. Following necropsy, histopathological lesions similar to those seen in the natural disease were observed in the liver or spleen of three birds which received 10³ cfu, and all birds dosed with ≥10⁵ cfu.

CONCLUSION: The results indicate that an isolate of S. Typhimurium DT60 originating from house sparrows in New Zealand is pathogenic to these birds and that the response is dose- dependent. The persistence and excretion of the pathogen may last for at least 10 days. This confirms that sparrows infected with DT160 could be a source of infection to humans and other in-contact animals.     

Experimental Infection of Newborn Calves with Coccidia and Reinfection after Weaning

Four newborn Hereford calves were orally inoculated five times with 100 sporulated oocysts of coccidia, predominantly Eimeria zurnii. Each calf was kept isolated with its dam until weaned at the age of 13 weeks. Three other newborn calves were similarly isolated but not experimentally infected. The calves were then challenged with 300,000 sporulated oocysts at the age of five, seven and nine months. The previously unexposed calves developed marked clinical coccidiosis after the first challenge, but resisted the second and third challenge. The neonatally exposed calves were susceptible to infection at the first challenge as well as to the next two challenges at seven and nine months of age, but the clinical signs following the last two challenges were milder than those of the first challenge. These findings suggest that under conditions where calves become infected with coccidia when very young, such calves may, by shedding oocysts in large numbers for long periods, be a continuing source of coccidial infections to other animals.     

THE EFFECT OF AGE ON RESISTANCE OF CATTLE TO BABESIA BOVIS

SUMMARY Susceptible Hereford cattle of different ages were inoculated with 2 times 10⁸Babesia bovis organisms. Experiment 1 consisted of cows aged 6 to 7 years, steers aged 17 to 18 months and calves aged 5 to 6 months, while experiment 2 consisted of cows aged 6.5 to 7.5 years, steers aged 23 to 24 months and yearlings aged 11 to 12 months. Daily measurements of temperature, parasitsemia and packed cell volume were made in order to determine susceptibility of the different ages. Twenty-four of the 36 animals in experiment 1, which included all 12 cows, required treatment. One cow died as a result of an enlarged ruptured spleen, and 2 steers and 1 calf died with classical babesiosis symptoms. No treatment was given to experiment 11 animals, and 5 of the 12 cows died, but the steers and yearlings underwent relatively mild reactions. Statistical analysis confirmed the high susceptibility to B. bovis of the aged cows in both experiments, and the innate resistance of 5 to 6 month old calves in experiment 1. The reaction of the 18-month-old steers in experiment 1 was significantly greater than that of the calves, but significantly less severe than that of the aged cows. Two-year-old steers and yearlings in experiment 2 underwent similar mild reactions, suggesting that innate immunity may persist for longer periods when compared to aged cows. Age groups showing reduced susceptibility were found to reach peak parasitaemia, temperature and anaemia before the more susceptible age groups. Heterologous challenge of the remaining experiment 1 and experiment 2 animals at 6 and 8 months respectively after primary inoculation, revealed all animals of all ages had a solid resistance to B. bovis.     

The occurrence of Cryptosporidium parvum,Campylobacter and Salmonella in newborn dairy calves in the Manawatu region of New Zealand

AIM: To determine the occurrence of Cryptosporidium parvum oocysts, Campylobacter spp and Salmonella spp in faecal samples taken from newborn dairy calves on 24 dairy farms in the Manawatu region of New Zealand.

METHODS: A cross-sectional study was conducted during the 2002 calving season. Faecal samples were collected from 185 newborn calves from a convenience sample of 24 dairy farms. The samples were tested microscopically for the presence of C. parvum oocysts, and bacteriologically for the presence of Campylobacter spp and Salmonella spp.

RESULTS: Infections with C. parvum were identified in 33/156 (21.2%) calves from 10 farms. More than 10⁶ oocysts/g (OPG) faeces were detected in calves from four farms. Campylobacter spp were isolated from 58/161 (36%) calves from 18 farms; in particular, C. jejuni subsp jejuni was isolated from 11/161 (6.8%) calves from seven farms. Salmonellae were not detected.

CONCLUSIONS: Despite the short and concentrated calving pattern and the long interval between calving seasons characterising most dairy farms in New Zealand, C. parvum is widespread among calves. Campylobacter spp, especially C. jejuni, rapidly colonise the intestinal tract of newborn calves.

RELEVANCE: This study provided an estimate of the ecological impact of newborn dairy calves with regard to the potentially zoonotic enteric pathogens most frequently isolated from human gastrointestinal infections in New Zealand.     

Sheep do not have a major role in bovine herpesvirus 1 transmission

With regard to BHV1 eradication programs in cattle it is important to know whether sheep can be a reservoir of BHV1. We therefore performed an experiment that consisted of three phases. In phase 1, 10 sheep were inoculated with high doses of BHV1 and kept in close contact with 5 sheep and 5 calves. All inoculated sheep excreted BHV1 between 8 and 15 days post inoculation and seroconverted. Although BHV1 was isolated from the nasal mucosa of 3 out of 5 sentinel sheep, none of the sentinel sheep produced antibodies against BHV1. One sentinel calf excreted BHV1 through days 12–17; the remaining 4 calves excreted BHV1 between days 18 and 24, suggesting that the first calf was infected by sheep and the remaining 4 sentinel calves were infected by that calf and not by sheep. The bacic reproduction ratio (R₀) of BHV1 between sheep and calves was estimated at 0.1, and among calves it was estimated at ≥9. In phase 2, all inoculated sheep were treated with dexamethasone and kept in close contact with 5 sheep and 5 calves. All dexamethasone treated sheep re-excreted BHV1 over a 6- to 9-day period. None of the sentinel animals seroconverted. In phase 3, the sentinel sheep and calves of phase 1 were kept in two groups and were treated with dexamethasone. None of the sentinel sheep re-excreted BHV1, whereas 3 out of 5 sentinel calves did. It is concluded that while BHV1 infection in sheep is possible, BHV1 does not spread from sheep easily to cattle.     

Survival of Oocysts of Eimeria alabamensis on Pastures under Different Climatic Conditions in Sweden

The extent to which oocysts of the coccidian parasite Eimeria alabamensis can survive the winter and cause clinical coccidiosis in different parts of Sweden was investigated. Fecal samples were collected between May and July 1993 from calves on 59 farms where calves had grazed the same pasture for at least 5 consecutive years. The farms were situated in 9 regions of Sweden with different climatic conditions in the winter. On each farm, 5 samples of feces were collected from the floor of the calf-house before the calves were turned out in the spring, and again from the pasture on days 4 or 5, 8 or 9 and 10 or 11 after they were turned out. Overwintering of oocysts of E. alabamensis was considered to have occurred if an increase in the excretion rate of oocysts of this species could be demonstrated 8 to 11 days after calves had been turned out to pastures that had not been grazed since the previous autumn. Oocysts were shown to have overwintered on 27 farms, representing all 9 regions. Samples from 20 (34%) of the farms representing all the climatic regions contained more than 850000 oocysts per g of feces. This was comparable with the numbers found in animals with clinical coccidiosis due to E. alabamensis. Delaying turnout until the beginning of July did not affect the infection rate of the calves. However, calves which were turned out to pastures that had been grazed by older cattle or horses, either earlier in the spring or in previous years, excreted significantly fewer oocysts than calves which were turned out to pastures that had been grazed only by calves. A questionnaire answered by 321 dairy farmers revealed that of the 298 farmers who turned their first-season grazing cattle out to traditional pastures, 179 (60%) had used the same pasture for at least 5 years. These 179 farmers had experienced a significantly higher incidence of diarrhoea in their calves during the first 2 weeks at pasture than those farmers who had used different pastures.     

Anticoccidial effects of <Emphasis Type="Italic">Aloe secundiflora</Emphasis> leaf extract against <Emphasis Type="Italic">Eimeria tenella</Emphasis> in broiler chicken

Anticoccidial effects of Aloe secundiflora crude leaf extract was tested in broiler chickens following oral infection with Eimeria tenella. Sixty 22-day-old birds were divided into six groups of ten birds each. Three treatment groups A, B, and C were fed with the extract (100, 250, and 500 mg/day, respectively) mixed in feed for 10 days, and three control groups: group D (drug control) administered 300 mg/l of sulfachloropyrazine sodium soluble powder in drinking water for 5 days, group E (infected/non-medicated positive control), and group F (uninfected/non-medicated negative control). Except for group F, all groups were orally inoculated with 75,000 sporulated oocysts of E. tenella. The effects of the extract on E. tenella infection were evaluated by severity of bloody diarrhea, body weight (BW) gain, oocyst output, and lesion score. No bird in the treated groups died of coccidiosis, and severity of bloody diarrhea was milder than in the positive control group. BW gains in the treated groups were significantly higher than in group E (p < 0.05). The lesion scores of the treated groups were significantly lower than that of group E. Oocyst output in groups A, B, and C were 11.23, 8.24, and 6.82 × 10⁶, respectively. As compared with the negative control group (12.84 × 10⁶), the reductions in oocyst production were 12.54, 35.83, and 46.88%, respectively. Oocyst output significantly reduced with an increase in Aloe dosage. The findings of this study suggest that Aloe secundiflora extract presents an alternative anticoccidial agent for the control of avian coccidiosis.     

Comparative effects of Herba Cox®, a commercial herbal extract,on rabbits (Oryctolagus cuniculus) experimentally infected with Eimeria stiedae

The objective of this study was to evaluate the efficacy of Herba Cox®, a commercial herbal compound containing extracts from Bombax malabaricum, Aegle marmelos, Anethum foeniculum, Resina salvia, Ferula asafoetida and Papaver somniferum, for the treatment of rabbit hepatic coccidiosis. Thirty rabbits were allocated into three groups (10 × 3), the G1 group served as a negative control group, G2 group (positive control group) was infected with 5 × 10⁴ sporulated E. stiedaeoocysts and served as infected-untreated group, and G3 group was infected with 5 × 10⁴ sporulated E. stiedaeoocysts and treated with Herba Cox®, 1 ml/liter of drinking water, starting 7 days before infection and continuing for 4 weeks post-infection. When compared to the infected group (G2), body weight and weight gain were significantly (P ≤ 0.05) increased, the feed conversion rate was improved and no mortality was detected in infected treated group (G3) and similar to negative control group (G1). In addition, faecal oocyst output and liver enzymes were significantly decreased. Malondialdehyde, nitric oxide, and glutathione concentrations observed in G3 were similar to those in G1. In infected-untreated rabbits (G2), the haemoglobin, lymphocytes, and CD4+/ CD8+ ratio were significantly decreased, while the total leukocyte count, percentage of heterophils, and heterophil/lymphocyte ratio were increased. Significantly more severe histopathological hepatic lesions were observed in G2 when compared to G1 and G3. In conclusion, the obtained results showed that Herba Cox® should be considered a safe and novel effective compound for the treatment of E. stiedae infection in rabbits.