Role of oregano and Citrus species-based essential oil preparation for the control of coccidiosis in broiler chickens

Background:Due to presence of drug-resistant Eimeria strains and raised public health safety concerns about drug residues in the meat,there is renewed interest in the search for natural alternatives to the coccidiosis control agents.This study was conducted to test the anticoccidial efficacy of oregano and Citrus spp.-based essential oils for broilers.Methods:A total of 2807-day-old broiler chicks were fed a control diet or diets with salinomycin or essential oils for up to 35 d of age.On d 14,half of the control groups and the treated groups were orally challenged with a coccidiosis vaccine at 25 times higher than the recommended vaccine dose.Control diet-fed chickens that were gavaged with phosphate-buffered saline were considered non-challenged control group.Results:Eimeria challenge or dietary additives failed to affect growth performance during the 7 to 20 d growth period although essential oil-fed chickens exhibited the lowest body wight gain(P=0.332)and the highest feed conversion ratio(P=0.062).Oocysts in the litter were detected in the challenged control diet group and the challenged/essential oil-fed groups at 21 and 35 d,respectively.Superoxide dismutase activity in the serum was elevated(P=0.059)in the salinomycin-fed chickens compared to the challenged controls.Alpha-1-acid glycoprotein was decreased by 28.7%in the salinomycin-fed chickens but increased by 38.1%in the essential oil group compared with the challenged control group.Challenged control group exhibited a significantly higher cooking loss of the thigh meat,compared to the non-challenged control diet group,which was marginally mitigated by dietary supplementation with essential oils.Chickens fed essential oil-added diet had the highest branched-chain fatty acids contents in the cecum.Conclusions:In conclusion,this study shows that oregano and Citrus-based essential oil preparation did not affect growth performance in broiler chickens challenged with the coccidiosis vaccine nor did Eimeria-specific duodenal lesion.However,dietary essential oil preparation lowered oocysts present in litter materials and altered branchedchain fatty acids in cecal digesta.Beneficial findings of the essential oil preparation on volatile fatty acids and oocysts output may warrant further research into assessing its effectiveness and its efficacy in pathogenic fieldisolate Eimeria spp.-induced coccidiosis disease model.

Coccidiosis of Goats in Florida, USA

Fecal samples from 277 goats on eleven farms in Florida were examined to determine the prevalence and intensity of the multiple species of Eimeria that infect goats in this region. The number of oocysts per gram of feces (OPG) was determined by the modified McMaster technique. Species identification was done following sporulation. Eimeria oocysts were found in 97% of the fecal samples. Goats less than one year of age shed significantly more oocysts than goats greater than one year of age (P < 0.01). Goats of the Nubian breed had the highest OPG counts when compared to Boer, Boer-Spanish crosses, and Saanen breeds. Nine Eimeria spp. were identified. Eimeria arloingi (91%), E. ninakohlyakimovae (82%) and E. alijevi (79%) were the most prevalent species. Other species present were E. caprina (60%), E. christenseni (60%), E. hirci (46%), E. caprovina (29%), E. aspheronica (15%), and E. jolchijevi (9%).

Diagnosis and Etiology of Secondary Infection of Escherichia coli with Rabbit Coccidiosis

In November 2012,diarrhea-predominant disease broke out in a large rabbit farm in Huaihua City,leading to mortality rate of 5. 3%. Through survey of incidence,combined with clinical symptoms,pathological changes and laboratory diagnosis,the disease was confirmed as secondary infection of E. coli with rabbit coccidiosis,and it had been controlled after drug treatment.

Epidemic Status and Research Progress on Prevention of Rabbit Coccidiosis in China

Rabbit is not only an economic animal, but also an important experimental animal. Rabbit coccidiosis seriously affects development of rabbit industry and quality safety of experimental rabbits. Currently, infections of rabbit coccidiosis are very common in China, which mostly are mixed infections in clinical, with multiple species of coccidia. The current prevention against rabbit coccidiosis mainly depends on anticoccidial drugs, while live vaccine, subunit vaccines and ge- netic engineering vaccine for coccidia are developing.

Efficacy of Different Concentrations of Aloe chabaudii Leaf Gel as a Substitute for a Sulfonamide for the Control of Avian Coccidiosis

The objective of this study was to investigate the effectiveness of Aloe chabaudii schonland juice as a potential substitute of sulphonamide drugs and to measure its effects when administered at different concentrations in the control of avian coccidiosis. 30 cobb and 500 broiler chickens were used for the experiment. The broilers were randomised into six groups of five birds each and the groups were assigned to six treatments in a Complete Randomised Design (CRD). Four of the groups were given any one of the following treatments, different concentrations of Aloe (weight/volume: 10%, 20% and 30%) and a sulphonamide. There was a control group which was not given a treatment and one cohort group which was neither infected nor treated. At two weeks of age, 25 of the birds were infected with coccidia via drinking water using infected chicken fecal matter, while the remaining five birds were left uninfected. Infection proceeded for 1 week and after the infection period, fecal oocysts were counted from each individual bird using the McMaster technique. Treatments started one day after the infection and continued for one week after 20 gram samples of fecal matter were taken from each bird per treatment and oocysts were counted. After oocyst counting, all birds were slaughtered and lesion scoring was done on the intestines using the Johnson and Reid technique. Data was analysed for oocysts count in different treatments, fecal egg count reduction, relative risk of coccidiosis and the effectiveness of Aloe concentrations as a substitute for a commercial sulphonamide. The results showed that the concentrations of Aloe used in the experiment were not effective as compared to the sulphonamide in controlling coccidiosis as the fecal egg reduction was below 90% for all concentrations. The relative risk of coccidiosis infection in the farm was found to be 100%, meaning that coccidiosis is a disease of economic importance at the farm. However, there was a reduction in the fecal oocyst count with increase in Aloe juice concentration to control coccidiosis, though this could not be compared to sulphonamide (ESB3) which was more effective (p 0.05). This study has shown that there is potential for use of Aloe chabaudii leaf gel as a chemotherapeutic though much research is needed to determine absolute concentrations which will make it comparable to commercially available drugs in terms of efficacy.

Effect of Artemisia annua L. as Substitute to Sulfonamides (Sodium Sulfadimerzine) on Coccidiosis and Growth Performance in Rabbits

Coccidiosis is a disease caused by protozoa of the genus Eimeria which seriously affects young rabbits. Treatment based on the use of anticoccidial drugs is increasingly ineffective due to the rapid emergence of resistant strains of coccidia and the high cost of drugs. Consumer demand for rabbit products without chemical residues led to a growing interest in the use of medicinal plants as an alternative treatment for coccidiosis. The present study was carried out during the period of August to December 2020 to assess the anticoccidial effect of hydro-ethanolic extract of leaves of Artemisia annua L., in young rabbits. The antiparasitic efficacy of Artemisia extract was tested on 15 young rabbits (whose age varied between 7 and 9 weeks) divided into 5 lots of 3 animals. The average weight of these animals was 790 g. The results of this study show that the feces samples and the weight of young rabbits before administration of the treatment and the coprological examination (every 7 days for 4 weeks) show a fecal excretion reduction rate (FECRT) of 55.13% in the lot treated by sulfonamide. On the other hand, in animals received treatments extract of the leaves of Artemisia annua L., the average FECRT is evaluated at 69.64%, 79.22%, and 96.36% for respective doses of 400, 800 and 1200 mg/kg bodyweight and proves their anticoccidial effect. Furthermore, the variation in mean Eggs Per Gram (EPG) of coccidia and the average weekly weight gain (AWWG) of each lot were significant in the lots treated with hydro-ethanolic extract (P 0.05). The greatest reductions in oocystal excretion and weight gain obtained were those of lot 5, treated at 1200 mg/kg of hydro-ethanolic leaves extract of Artemisia annua L.

Five years Retrospective Study of Avian Coccidiosis in a Veterinary Clinic Bukuru Plateau State Nigeria

This study was conducted to evaluate the incidence of avian coccidiosis and its associated various risk factors such as age,type of birds and season in a private veterinary clinic in Bukuru,Plateau State Ngeria.A total of 9406 cases during 2013–2017 were analysed and 1556 of them were positive for coccidiosis.There are several reports on the prevalence of avian coccidiosis by previous researchers;however,in this study we evaluated the prevalence of avian coccidiosis in the study area and its economic impacts.Total prevalence of 12.14%in 2013,18.78%in 2014,18.21%in 2015,16.82%in 2016 and 19.07%in 2017 were reported.An overall prevalence of 85.02%was recorded.The average prevalence of coccidiosis based on this five years study is 17%.The association between coccidiosis and age of the birds was determined and age 5-8 weeks becomes most effective period with wet season having high percentage prevalence of coccidiosis.Based on the type of birds,coccidiosis is prevalence almost in equal proportion in both broilers and layers.The losses caused by avian coccidiosis could be both direct and indirect components which may include the cost of control measures,inadequate good hygiene practices,production losses and lack of prophylaxis treatment.The control of avian coccidiosis can be achieved through good sanitary measures by avoiding water spillage on the pen floor,overcrowded stocking density,the use of prophylaxis-anticoccidials and proper good vaccination practices.

Effects of methionine supplementation in a reduced protein diet on growth performance, oxidative status, intestinal health, oocyst shedding, and methionine and folate metabolism in broilers under Eimeria challenge

Background This study investigated effects of different methionine(Met)supplementation levels in a reduced protein diet on growth performance,intestinal health,and different physiological parameters in broilers under Eimeria challenge.A total of 600 fourteen-day-old Cobb500 male broilers were challenged with E.maxima,E.tenella,and E.acervulina,and randomly allocated in a 2×5 factorial arrangement.Birds received normal protein diets(20%crude protein,NCP)or reduced protein diets(17%crude protein,LCP),containing 2.8,4.4,6.0,7.6,and 9.2 g/kg of Met.Results On 6 and 9 days post inoculation(DPI),increasing Met level linearly improved the growth performance(P<0.05).Total oocyst shedding linearly increased as Met level increased(P<0.05).Duodenal villus height(VH):crypt depth(CD)in the LCP groups were higher on 6 DPI(P<0.01)while lower on 9 DPI(P<0.05)compared to the NCP groups.Jejunal CD and duodenal VH:CD changed quadratically as Met level increased(P<0.05).On 6 DPI,liver glutathione(GSH)and glutathione disulfide(GSSG)linearly increased as Met level increased(P<0.05).On 9 DPI,GSSG quadratically increased,whereas GSH:GSSG quadratically decreased as Met levels increased(P<0.05).The expression of amino acid transporters linearly decreased as Met level increased(P<0.05).The expression of zonula occludens 2 and claudin-1 linearly increased on 6 DPI whereas decreased on 9 DPI as Met level increased(P<0.05).The expressions of cytokines were lower in the LCP groups than the NCP groups(P<0.05).Interaction effects were found for the expression of IL-10 and TNFαon 6 DPI(P<0.05),where it only changed quadratically in the NCP group as Met level increased.The expression of Met and folate metabolism genes were lower in the LCP groups than the NCP groups on 9 DPI(P<0.05).The expression of these genes linearly or quadratically decreased as Met level increased(P<0.05).Conclusion These results revealed the regulatory roles of Met in different physiological parameters including oxidative status,intestinal health,and nutrient metabolism in birds fed reduced protein diet and challenged with Eimeria.

金丝桃素抗鸡球虫效果观察

为探明金丝桃素是否具有抗鸡球虫的作用,特进行了金丝桃素体外抗球虫孢子化试验及体内抗球虫试验。体外抗球虫孢子化试验结果表明,金丝桃素浓度达到0.03%即有明显的抑制球虫孢子化的作用;体内抗球虫试验也表明金丝桃素具有抗鸡球虫的活性,服用金丝桃素6、8、10、12 mg/只,其抗球虫指数分别为66.1、100.3、126.0、131.3。研究结果为拓展药物资源应用的新领域、研发抗球虫新药提供了良好基础。

Dietary supplementation with free methionine or methionine dipeptide mitigates intestinal oxidative stress induced by Eimeria spp. challenge in broiler chickens

Background: This study evaluated the effects of Eimeria spp. challenge and dietary supplementation with free methionine or methionine dipeptide on animal performance;expression of genes associated with the immune system, antioxidant system, and amino acid transport in the jejunum;and redox status of the jejunum of broiler chickens.Methods: A randomized, 2 × 3 factorial design was used, in which Eimeria spp. challenge was the first factor(Eimeria-challenged, EC, or unchallenged, UC, broilers) and methionine supplementation was the second factor(non-supplemented, NS;free DL-methionine, DL-Met;and methionine dipeptide, DL-methionyl-DL-methionine, DLMMet). At 14 days of age, chickens were inoculated orally with sporulated oocysts of Eimeria acervulina, Eimeria praecox, Eimeria maxima, and Eimeria mitis. Birds were killed by cervical dislocation 144 h post-inoculation(PI), and the jejunum was collected for biochemical and molecular analyses.Results: EC broilers had a 13% lower feed intake(FI), 37% lower body weight gain(BWG), and 39% higher feed conversion ratio(FCR) than UC broilers. Chickens fed the DL-Met diet had higher BWG(about 12% higher) and better FCR(about 12% lower) than chickens fed the NS diet. EC chickens had lower relative weight of the bursa of Fabricius(51.8%) and higher relative weights of the spleen and whole intestine(53.6% and 26.3%, respectively) than UC chickens. Eimeria spp. challenge led to an increase in the levels of oxidative substances, such as nitrite and thiobarbituric acid reactive substances(TBARS), in the jejunum of chickens 144 h PI. Among UC chickens, those fed the DL-Met diet had higher total antioxidant capacity(TAC) and lower catalase(CAT) and superoxide dismutase(SOD) activities. EC chickens that received the NS diet had higher carbonylated protein content(CP). This result was associated with their lower TAC and catalase activity. The lower TAC in EC chickens might have been due to reduced expression of catalase(CAT) and superoxide dismutase 1(SOD1) genes. Chickens fed the DL-Met and DLMMet diets had lower nitrite content. Eimeria spp. challenge suppressed neutral amino acid transporter 1(B0 AT1),peptide transporter 1(PEPT1), toll-like receptor 5(TLR5), interleukin 2(IL2), and occludin(OCLN) gene expression and enhanced cationic amino acid transporter 1(CAT-1) and interferon gamma(IFNG) gene expression. The highest PEPT1 expression level was observed in broilers fed the DL-MMet diet, and the lowest TLR5 expression level was found in broilers fed the NS diet.Conclusion: Our results show for the first time that supplementation with methionine as free amino acid or dipeptide helps protect the intestinal cells of broilers under Eimeria spp. challenge from the oxidative damage induced by free radicals, mainly through modulation of the antioxidant system.

Neutrophil extracellular traps in the intestinal mucosa of Eimeria-infected animals

Objective:To investigate the presence of neutrophil extracellular traps(NETs) in vivo by analysing intestinal sections from experimentally Eimeria bovis-and naturally Eimeria arloingi-infected animals.Methods:Intestinal samples of Eimeria arloingi-and Eimeria bovis-infected animals were analysed by using immunohistochemical and fluorescence approach by using monoclonal antibodies.Results:Classical NET components were confirmed by co-localization of extracellular DNA being decorated with neutrophil elastase and histones in Eimeria-infected tissue samples.Here,extrusion of NETs was exclusively detected in intestinal polymorphonuclear neutrophils infiltrating Eimeria-infected sites.In vivo NETs were either found in close proximity or in direct contact to different Eimeria stages suggesting a stage-independent process.NETs were also found within the gut lumen driven by polymorphonuclear neutrophils that were contacting released oocysts.Conclusions:We postulate that NETs might play an important role in innate defence reactions in coccidiosis therefore significantly altering the outcome of infection.

A Combinative Assembly Strategy Inspired Reversibly Borate-Bridged Polymeric Micelles for Lesion-Specific Rapid Release of Anti-Coccidial Drugs

Stimuli-triggered drug delivery systems hold vast promise in local infection treatment for the site-specific targeting and shuttling of drugs.Herein,chitosan conjugates(SPCS)installed with sialic acid(SA)and phenylboronic acid(PBA)were synthesized,of which SA served as targeting ligand for coccidium and reversible-binding bridge for PBA.The enhanced drug-loading capacity of SPCS micelles was attributed to a combination assembly from hydrophobicity-driving and reversible borate bridges.The drug-loaded SPCS micelles shared superior biostability in upper gastrointestinal tract.After reaching the lesions,the borate bridges were snipped by carbohydrates under a higher pH followed by accelerated drug release,while SA exposure on micellar surface facilitated drug cellular internalization to eliminate parasites inside.The drugmicelles revealed an enhanced anti-coccidial capacity with a higher index of 185.72 compared with commercial preparation.The dual-responsive combination of physicochemical assembly could provide an efficient strategy for the exploitation of stable,safe and flexible anti-infectious drug delivery systems.

Maximum Entropy Ecological Niche Prediction of the Current Potential Geographical Distribution of <i>Eimeria</i>Species of Cattle, Sheep and Goats in Mexico

Coccidiosis is a gastrointestinal disease caused by parasites of the genus Eimeria. To produce the ecological niche model for the geographic distribution of Eimeria species, the maximum entropy algorithm (MaxEnt) was used and 19 bioclimatic variables with a spatial resolution of 30 arc-seconds (approximately 1 km2) were downloaded from the World Climate Database. These were reduced to BIO2, BIO3, BIO4, BIO7 and BIO15 for each species after examining cross-correlations among them to account multicollinearity. A jackknife analysis was included to assess the contribution of five bioclimatic variables and the fit of the model was evaluated with the area under receiver operating characteristic curve (AUC). Under a current climate scenario, the jackknife evaluation of the MaxEnt model showed that BIO4 (temperature seasonality) made the greatest contribution to the distribution model for 22 Eimeria species;whereas BIO7 (temperature annual range) was the most important factor that contributes to the distribution model of 10 species. The habitat suitability model based on the maximum entropy theory was supported by AUC values higher than 0.9 and predicted that the suitable habitats for different species of Eimeria are present in southern, eastern and western areas of Mexico. Our study may support future studies exploring factors that constrain the distribution of Eimeria as well as strategies aimed at reducing the disease prevalence.

The Effect of a<i>Lactobacillus</i>-Based Probiotic for the Control of Necrotic Enteritis in Broilers

Necrotic Enteritis (NE) caused by Clostridium perfringens (CP) in poultry is probably the most important bacterial disease in terms of economic implications. The disease is multi-factorial and is invariably associated with predisposing factors. The present study investigated the effect of a commercially available Lactobacillus-based probiotic (FM-B11) for the control of necrotic enteritis in broiler chickens. In experiment 1, one-day-of-hatch broiler chicks were randomly allocated to the following treatment groups: 1) Non-challenged (NC);2) Challenged (C);3) Challenged + probiotic (C+ FM-B11). Prior to placement, chicks in groups 2 and 3 received 0.25 mL of Salmonella typhimurium (ST) containing 105 cfu of viable cells by oral gavage. At 14, 15 and 16 days of age, all chicks in group 3 were treated with FM-B11 in the drinking water at a concentration of 106 cfu/ml. At 21d of age, all chicks in groups 2 and 3, were individually challenged with 5 × 104 sporulated oocysts of E. maxima by oral gavage. At 26d of age, all chicks in groups 2 and 3, were individually challenged with 108 cfu CP;body weight (BW) was recorded prior to challenge. The experiment was terminated at 29 days of age and the following parameters were evaluated: NE-associated mortality, CP lesion scores, CP concentrations in ileum, BW, and body weight gain (BWG). Chicks treated with FM-B11 had significantly (P < 0.05) higher body weight gain after challenge when compared to control challenge chickens. Total mortality was higher in the C group (48.8%) when compared to the C + FM-B11 (12.7%). Even though there was no significant (P > 0.05) difference in lesion score between C and C + FM-B11, group C + FM-B11 had significantly (P < 0.05) lower total number of cfu of CP recovered from the ileal mucosa and content samples when compared to group C. Experiment 2 was a unique and remarkable case report of a field outbreak of NE in a commercial broiler farm in Argentina. A reduction and control of the mortality associated with NE following 3 days of administration of FM-B11 was observed as compared with the control non treated house. These results imply that the commercially available Lactobacillus-based probiotic FM-B11 was able to reduce the severities of NE, as a secondary bacterial infection, in an experimental NE challenge model;as well as, in a commercial field outbreak of NE.

Pharmacokinetics of oral ethanamizuril solution in chickens

Ethanamizuril(EZL) is a novel triazine anticoccidial compound that has high anticoccidial activity in chickens. In order to treat coccidiosis rationally in poultry, a detection method was developed for ethanamizuril in broiler plasma, and then the pharmacokinetics studies were performed in broilers after oral administration of different dose levels. Ethanamizuril was administered as single oral doses at low(0.67 mg kgBW), medium(1.33 mg kgBW) and high(6.67 mg kgBW) levels in which the medium dose was that recommended in clinics. Plasma concentrations of ethanamizuril were determined using ultra-high performance liquid chromatography and the data were analyzed with a non-compartmental model. Peak plasma concentrations of ethanamizuril were(2.16±0.57),(3.91±0.71), and(23.71±5.02) mg Lat(5.17±1.80),(4.60±2.12), and(4.60±2.12) h, respectively. The terminal elimination half-lives(t) for ethanamizuril were(10.84±2.59),(10.66±2.47), and(13.34±3.10) h after oral administration at low, medium and high doses, respectively. The areas under the concentrationtime curve(AUC)) were(37.68±6.87),(73.19±9.18), and(485.76±125.10) mg Lh with mean residence times(MRT) of(14.79±3.03),(15.57±3.69), and(20.22±4.01) h at the 3 dosages, respectively. Ethanamizuril was absorbed rapidly and eliminated slowly. A comparison across the dose range indicated that the time to reach peak plasma concentration(T) values were similar while peak plasma concentration(C) and AUCwere positively correlated with increasing dosages. This study of the pharmacokinetics of an ethanamizuril solution in chickens provides a theoretical basis for the rational use in the clinic.

Pathomorphologic Study of Parasitic Enteritis Caused by Acute Canine Distemper

[Objective]The aim was to survey relationship between acute canine distemper and parasitic enteritis from pathology. [Method]Twelve cases of acute canine distemper with diarrhea were researched as per immunohistochemistry,Haematoxylin Eosin,and PAS staining kit. [Result] Of the twelve diseased dogs （ with diarrhea） ,six were detected caused by coccidium and two were detected by cryptosporidium. Coccidian protozoa is mainly in epithelial cells of jejunum and ileum,and some can be found in cut-off intestinal epithelial cells and in mucus formed by destroyed intesti- nal villus. The most common shapes of coccidian protozoa are trophozoite and schizont. The former is mainly within or among epithelial cells; nucle- us is in center and stained by hematoxylin; protoplasm is in ＂ fined mesh＂ shape. The latter,round or oval,contains much glycogenosome in de- generated intestinal epithelial cells. On the other hand,cryptosporidium is mainly in striated borders of intestinal epithelial cells and intestinal gland cells,leading to destruction of villus and cut-off of cells. Through detection on monoclonal antibody of nucleocapsid proteins of anti-canine distemper virus,it was found that epithelial cells in intestinal mucosa,glandular cells in recesses,lymphocytes and macrophage infittrated in lamina propria and dendritic cells in aggregated nodule were all with positive reactions. [Conclusion]Parasitic diarrhea caused by acute canine distemper occurs when resistance of intestinal mucosa caused by canine distemper virus begins to decline.

Clinico-pathological Studies in Experimental Eimeria Infection in Domestic Rabbits （Oryctolagus Cuniculus）

Clinico-pathological study of experimental Eimeria species infection （coccidiosis） such as E. magna, E. intestinalis, E. irresidua, E. media and E. perforans in rabbits was conducted with dose inocula of 1 lac sporulated oocysts. These rabbits were divided into two groups each consisting of 12 rabbits. Two rabbits of infected untreated group died of severe disease on the 27^th ＆ 28^th day post infection. The intestine of dead animals showed elevated lesions in the middle half portion with congestion and destruction of villar epithelium.

Mate choice is affected by parasite infestation rate of the choosing individual as well as of potential mating partners

Parasites are known to be a key driving force in mate choice and are important for the expression and evolution of ornaments and behavioral traits being used.However,there is little experimental evidence on how the parasite’s burden of the choosing individual is integrated into the mate-choice process and how it affects decision-making,especially in relation to parasite infestation of potential mates.Thus,the aim of our study was to determine whether female house sparrows Passer domesticus adjust their mate preference according to their own as well as the parasite load of prospective partners.To do this,we experimentally manipulated female parasite load and determined their mate preferences prior to and after parasite treatment.We manipulated the chronic coccidian parasite burden of females either by initiating the acute infection phase via re-infecting them with coccidian or by temporally reducing the parasite load of coccidia.We then measured the effect of this manipulation on mate preference by presenting females with a choice of four stimuli:three males with similar ornaments,but unmanipulated,naturally varying chronic coccidiosis levels,and an unmanipulated control female.Additionally,we recorded some males’behavior in relation to their infection status pointing toward an increased or reduced interest in mating.We found that females preferred highly infested males prior to manipulation,regardless of their own infestation level.However,after manipulation,infested females avoided highly infested males probably in response to the deterioration of their health condition by parasites.Our study suggests that mate-choice decisions are more complex when they are mediated by parasites.The implications of parasites for evolutionary theories of sexual signaling and mate choice are discussed.

Construction of EGFP-tagged rBCG of E.tenella and distribution in chickens

Chicken coccidiosis is a major parasitic disease with substantial economic burden to the poultry industry.Enhanced green fluorescent protein(EGFP) tagged recombinant Bacille Calmette-Guerin(rBCG),as a fusion protein with coccidian rhomboid antigen was constructed to track rBCG in vivo in chickens in this study.Immunization of chickens with one dose of rBCG pMV361-Rho/EGFP induced humoral immune response.The colonization of rBCG in liver,spleen,lung,kidney and caecum was observed by laser confocal microscopy.Real-time quantitative RT-PCR showed a rise expression level of rhomboid protein on the 7th day and a peak on the 14th day and disappearance on the 28th day after immunization.These results have significant implications for the development of rBCG vaccines against avian coccidiosis.

Dietary supplementation of sulfur amino acids improves intestinal immunity to Eimeria in broilers treated with anti-interleukin-10 antibody

Oral antibody to interleukin-10(anti-IL-10)enhances the intestinal immune defense against Eimeria.The sulfur amino acids methionine and cysteine(MtC)play essential roles in inducing and maintaining protective immune responses during intestinal infections.Hence,increased dietary MtC may support the anti-IL-10-induced intestinal immunity to Eimeria.Broilers(n=640)were arranged in a 2×2×2 factorial design with 2 levels of each of the 3 main factors:dietary standardized ileal digestible(SID)MtC levels(0.6%or 0.8%),dietary anti-IL-10 supplementation(with or without),and coccidiosis challenge(control or challenge).Briefly,the broilers were supplied with either 0.6%or 0.8%SID MtC,each with or without anti-IL-10(300 mg/kg),from d 10 to 21.On d 14,broilers from each diet were gavaged with either PBS or Eimeria.The resulting Eimeria infection induced fecal oocyst shedding and intestinal lesions.Broilers fed 0.8%SID MtC(main effects,P≤0.05)had decreased feed-to-gain ratio,increased duodenum and cecum luminal anti-Eimeria IgA titers,and decreased fecal oocyst counts,when compared to 0.6%SID MtC.The supplementation of anti-IL-10(main effects,P≤0.05)increased cecum luminal total IgA concentration and decreased cecum lesions.Interactions(P≤0.05)were detected for growth performance and cecum luminal IFN-γ.Briefly,the highest body weight gain and feed intake were reached in PBS-gavaged broilers fed 0.8%SID MtC with no anti-IL-10 and in Eimeria-challenged broilers fed 0.8%SID MtC with anti-IL-10.In Eimeria-infected broilers,anti-IL-10 increased intestinal luminal IFN-γ and body weight gain only at 0.8%SID MtC.Collectively,anti-IL-10 increased intestinal luminal IFN-γ levels,decreased cecum lesions and restored growth only when fed with adequate amounts of sulfur amino acids.Our findings underscore the importance of providing sufficient essential nutrients to support the anti-IL-10 induced immunity against coccidiosis.