In vitro and in vivo evaluation of chlorhexidine salts as potential alternatives to potassium dichromate for Eimeria maxima M6 oocyst preservation

IntroductionCoccidiosis caused by the Eimeria spp., an Apicomplexan protozoon, is a major intestinal disease that affects the poultry industry. Although most cases of coccidiosis are subclinical, Eimeria infections impair bird health and decrease overall performance, which can result in compromised welfare and major economic losses. Viable sporulated Eimeria oocysts are required for challenge studies and live coccidiosis vaccines. Potassium dichromate (PDC) is typically used as a preservative for these stocks during storage. Although effective and inexpensive, PDC is also toxic and carcinogenic. Chlorhexidine (CHX) salts may be a possible alternative, as this is a widely used disinfectant with less toxicity and no known carcinogenic associationsMethodsIn vitro testing of CHX gluconate and CHX digluconate exhibited comparable oocyst integrity and viability maintenance with equivalent bacteriostatic and bactericidal activity to PDC. Subsequent use of CHX gluconate or digluconate-preserved Eimeria oocysts, cold-stored at 4°C for 5 months, as the inoculum also resulted in similar oocyst shedding and recovery rates when compared to PDC-preserved oocysts.Results and discussionThese data show that using 0.20% CHX gluconate could be a suitable replacement for PDC. Additionally, autofluorescence was used as a method to evaluate oocyst viability. Administration of artificially aged oocysts exhibiting >99% autofluorescence from each preserved treatment resulted in no oocyst output for CHX salt groups

The effects of essential oil from Lippia origanoides and herbal betaine on performance, intestinal integrity, bone mineralization and meat quality in broiler chickens subjected to cyclic heat stress

Essential oils (EO) affect performance, intestinal integrity, bone mineralization, and meat quality in broiler chickens subjected to cyclic heat stress (HS). Day-of-hatch Cobb 500 male broiler chicks (n = 475) were randomly divided into four groups. Group 1: No heat stress (Thermoneutral) + control diets with no antibiotics; Group 2: heat stress control + control diets; Group 3: heat stress + control diets supplemented with thymol chemotype (45 ppm) and herbal betaine (150 ppm) formulation EO1; Group 4: heat stress + control diets supplemented with phellandrene (45 ppm) and herbal betaine (150 ppm) formulation EO2. From day 10–42, the heat stress groups were exposed to cyclic HS at 35°C for 12 h (8:00–20:00). BW, BWG, FI, and FCRc were measured at d 0, 10, 28, and 42. Chickens were orally gavaged with FITC-d on days 10 (before heat stress) and 42. Morphometric analysis of duodenum and ileum samples and bone mineralization of tibias were done. Meat quality was assessed on day 43 with ten chickens per pen per treatment. Heat stress reduced BW by day 28 (p < 0.05) compared to thermoneutral chickens. At the end of the trial, chickens that received both formulations of EO1 and EO2 had significantly higher BW than HS control chickens. A similar trend was observed for BWG. FCRc was impaired by EO2 supplementation. There was a significant increase in total mortality in EO2 compared with EO1 EO1 chickens had lower FITC-d concentrations at day 42 than the HS control. In addition, EO1 treatment is not statistically different if compared to EO2 and thermoneutral. Control HS broilers had significantly lower tibia breaking strength and total ash at day 42 than heat-stressed chickens supplemented with EO1 and EO2. Heat stress affected intestinal morphology more than thermoneutral chickens. EO1 and EO2 improved intestinal morphology in heat-stressed chickens. Woody breast and white striping were more common in thermoneutral chickens than heat stress chickens. In conclusion, the EO-containing diet could improve broiler chicken growth during cyclic heat stress, becoming increasingly relevant in antibiotic-free production in harsh climates

Evaluación del desprendimiento de oocistos de Eimeria maxima y Eimeria acervulina en pollos de engorde

The purpose of the present study was to evaluate the day and the time of sample collection of an experimental challenge with Eimeria maxima (EM) and Eimeria acervulina (EA) in broiler chickens. Oneday old male Cobb-Vantress broiler chickens were randomly allocated to one of three groups with ten replicates (n=8 chickens/replicate). Chickens were placed in battery cages with a controlled ageappropriate environment: Group 1) Negative control (no challenge or treatment); 2) Challenge control (Eimeria challenge only); 3) Challenge + Salinomycin. Challenged chickens were orally gavaged with the mixed culture of EM/EA (10,000 sporulated EM containing 4% wild-type EA) at 14 days of age. Performance parameters were recorded at days 7, 14, 20, and 23. Lesions scores were recorded post-mortem on days 20 and 23. Oocyst per gram (OPG) was performed on days six, seven, and eight post-challenge, and samples were collected at 9:00 AM and 6:00 PM on each day, respectively. Oocyst counts were significantly different (P < 0.05) between morning and afternoon on day six post coccidia challenge. The results of this study show that the day and the time at which samples are collected can have a significant effect on the reliability and validity of dataEl propósito del presente estudio fue evaluar el día y la hora de recolección de la muestra de un desafío experimental con Eimeria maxima (EM) y Eimeria acervulina (EA) en pollos de engorde. Los pollos de engorde macho Cobb-Vantress de un día de edad se asignaron aleatoriamente a uno de tres grupos con diez réplicas (n = 8 pollos / réplica). Los pollos se colocaron en jaulas de batería con un entorno controlado apropiado para la edad: Grupo 1) Control negativo (sin desafío o tratamiento); 2) Control de desafío (solo desafío Eimeria); 3) Desafío + salinomicina. A los 14 días de edad, los pollos fueron desafiados por vía oral con el cultivo mixto de EM / EA (10,000 EM esporulados que contenían 4% de EA de tipo salvaje). Los parámetros de rendimiento se registraron en los días 7, 14, 20 y 23. Los puntajes de las lesiones se registraron post mortem en los días 20 y 23. El oocisto por gramo (OPG) se realizó en los días seis, siete y ocho después del desafío, y muestras se recolectaron a las 9:00 a.m. y a las 6:00 p.m. de cada día, respectivamente. Los recuentos de oocistos fueron significativamente diferentes (P < 0.05) entre la mañana y la tarde en el día seis después del desafío con coccidios. Los resultados de este estudio muestran que el día y la hora en que se recolectan las muestras pueden tener un efecto significativo en la confiabilidad y validez de los dato

Research Note: Isolation, speciation, and anticoccidial sensitivity of Eimeria spp. recovered from wild turkey feces in the United States

ABSTRACT: Between 2018 and 2020, over 100 wild turkey fecal samples were collected from the Eastern and Central thirds of the United States, where commercial turkey production is uncommon. We hypothesized that anticoccidial-sensitive Eimeria spp. would be present in wild turkey fecal samples. Samples containing Eimeria spp. oocysts were amplified in vivo. If propagation was successful, the samples were PCR-speciated and subjected to anticoccidial sensitivity testing (AST) for key members of both ionophore and chemical categories of anticoccidial drugs. The purpose of this study was to isolate Eimeria spp. relevant to commercial turkey production that possessed sensitivity to monensin, zoalene, and amprolium. Future research would evaluate the efficacy of wild turkey Eimeria spp. as vaccine candidates for reducing coccidiosis in commercial turkey flocks utilizing single oocyst-derived stocks obtained in the present study

Assessment of Lippia origanoides Essential Oils in a Salmonella typhimurium, Eimeria maxima, and Clostridium perfringens Challenge Model to Induce Necrotic Enteritis in Broiler Chickens

The objective of the present research was to evaluate dietary supplementation of essential oils from Lippia origanoides (LEO) on necrotic enteritis (NE). Chickens were randomly assigned to three groups. Group 1: negative control; Group 2: positive control challenged with Salmonella typhimurium (day 1), Eimeria maxima (day 18), and C. perfringens (CP, days 22-23); Group 3: dietary supplementation LEO and challenged. On d 25 of age, serum samples were collected to evaluate fluorescein isothiocyanate-dextran (FITC-d), superoxide dismutase (SOD), gamma interferon (IFN-γ), Immunoglobulin A (IgA). Group 3 showed a significant reduction of the harmful effects of induced infection/dysbiosis and a significant reduction in NE lesion scores, morbidity and mortality compared with the positive challenge control group (p &lt; 0.05) compared with Group 2. Digested feed supernatant, supplemented with LEO and inoculated with CP, reduced CP burden (p &lt; 0.05). Group 3 also exhibited a significant reduction in FITC-d, IFN-γ and IgA compared with Group 2. However, a significant increase SOD was observed in Group 3 compared with both control groups. Further investigation to compare the effect of LEO and the standard treatment of clostridial NE is required

Experimental Cyclic Heat Stress on Intestinal Permeability, Bone Mineralization, Leukocyte Proportions and Meat Quality in Broiler Chickens

The goal of this research was to assess cyclic heat stress on gut permeability, bone mineralization, and meat quality in chickens. Two separate trials were directed. 320 day-of-hatch Cobb 500 male chicks were randomly assigned to four thermoneutral (TN) and four cyclic heat stress (HS) chambers with two pens each, providing eight replicates per treatment in each trial (n = 20 chicks/replicate). Environmental conditions in the TN group were established to simulate commercial production settings. Heat stress chickens were exposed to cyclic HS at 35 &deg;C for 12 h/day from days 7&ndash;42. Performance parameters, intestinal permeability, bone parameters, meat quality, and leukocyte proportions were estimated. There was a significant (p &lt; 0.05) reduction in body weight (BW), BW gain, and feed intake, but the feed conversion ratio increased in chickens under cyclic HS. Moreover, HS chickens had a significantly higher gut permeability, monocyte and basophil levels, but less bone mineralization than TN chickens. Nevertheless, the TN group had significant increases in breast yield, woody breast, and white striping in breast fillets compared to HS. These results present an alternative model to our previously published continuous HS model to better reflect commercial conditions to evaluate commercially available nutraceuticals or products with claims of reducing the severity of heat stress