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

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 < 0.05) compared with Group 2. Digested feed supernatant, supplemented with LEO and inoculated with CP, reduced CP burden (p < 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.

In ovo Administration of Defined Lactic Acid Bacteria Previously Isolated From Adult Hens Induced Variations in the Cecae Microbiota Structure and Enterobacteriaceae Colonization on a Virulent Escherichia coli Horizontal Infection Model in Broiler Chickens.

The effects of in ovo administration of a defined lactic acid microbiota (LAM), previously isolated from adult hens, in the cecae microbiota structure and Enterobacteriaceae colonization after exposure to virulent Escherichia coli during the hatching phase of broiler chickens were evaluated. Embryos inoculated with LAM showed a significant (P < 0.05) reduction of Enterobacteriaceae colonization at day-of-hatch (DOH) and day (d) 7. Furthermore, there was a significant increase in total lactic acid bacteria on DOH, body weight (BW) DOH, BW d7, and d0-d7 BW gain and reduced mortality d0-d7 was observed in the LAM group compared with that in phosphate-buffered saline (PBS) control. The bacterial composition at the family level revealed that the Enterobacteriaceae was numerically reduced, whereas the Ruminococcaceae was significantly increased in the LAM group when compared with that in the PBS control. Moreover, the bacterial genera Proteus and Butyricicoccus and unidentified bacterial genera of family Lachnospiraceae and Erysipelotrichaceae were significantly enriched in the LAM group. In contrast, the Clostridium of the family Peptostreptococcaceae and unidentified genus of family Enterobacteriaceae were significantly abundant in the PBS control group. In summary, in ovo administration of a defined LAM isolated from adult hens did not affect hatchability, improved body weight gain and reduced mortality at d7, induced variations in the cecae microbiota structure and reduced Enterobacteriaceae colonization on a virulent E. coli horizontal infection model in broiler chickens.

Research Note: Evaluation of a heat stress model to induce gastrointestinal leakage in broiler chickens.

The purpose of this study was to evaluate heat stress as a model to induce gastrointestinal leakage in broiler chickens. On the day of hatch, 320 chicks were allocated into 8 environmental chambers, 4 thermoneutral (TN) and 4 continuous heat stress (HS). Each chamber was divided into 2 pens containing separate feeders and water jugs (8 replicates per treatment, 20 birds/pen). The environment was established to simulate production setting as best possible for the first 21 D. A gradual reduction of temperature from 32°C to 24°C with relative humidity at 55 ± 5% was adopted for the first 21 D. At the time of HS, the HS groups were exposed to 35°C from Day 21 to 42, while thermoneutral ones were maintained at 24°C from Day 21 to 42. Chickens were equipped with a Thermochron temperature logger for continuous monitoring of core body temperature. The environmental temperature and relative humidity were continuously recorded. Fluorescein isothiocyanate-dextran (FITC-d) was orally gavaged to 2 chickens/replicate (n = 16) randomly selected on days 21, 28, 35, and 42. After 1 h of oral gavage, blood samples were collected to determine the passage of FITC-d. Tibias were removed from all chickens to evaluate break strength only on 21 D and 42 D (before HS and at the end of the trial). Performance parameters were evaluated weekly from 21 D to the end of the trial. Body temperature was significantly (P < 0.05) increased after 2 h of starting HS and remained that way until the end of the study. Chronic HS caused an increase in core body temperature which decreased feed intake, body weight, and feed efficiency (28, 35, and 42 D) when compared with control TN chickens. Similarly, serum FITC-d was significantly increased in HS chickens at all points of evaluation. Chronic HS also caused a significant reduction of bone strength at 42 D when compared with the control chickens. The results from the present study suggest that HS can be a robust model to induce gut leakage in broiler chickens.