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.

No abstract

Histomoniasis, caused by the protozoan parasite Histomonas meleagridis , is a disease to which turkeys are especially susceptible. Currently, no chemoprophylaxis compounds are available to mitigate this disease. Boric acid ( BA ) exhibits antifungal, antiseptic, and antiviral properties and has been used in the treatment of yeast infections. Based on these characteristics, an experiment was conducted to evaluate whether BA might be an efficacious prophylaxis against challenge with wild-type H. meleagridis ( WTH ). On day-of-hatch, poults were randomly assigned to either a basal control diet or a BA diet (basal diet + 0.2% BA). Groups consisted of a nonchallenged control ( NC ; basal diet), 0.2% BA + challenge (BA; 0.2% BA diet), and a positive-challenged control ( PC ; basal diet). On day 21, challenged groups were intracloacally inoculated with 2 × 10 5 WTH cells/turkey, and lesions were evaluated on day 14 postchallenge. Individual body weights were recorded on day 0, 21, and 35 to calculate the prechallenge and postchallenge body weight gain ( BWG ). The BA group resulted in lower prechallenge day 0 to day 21 BWG ( P = 0.0001) than the NC group. Postchallenge day 21 to day 35, BWG was also lower ( P = 0.0503) in the BA group than the PC group. No differences between the BA and PC groups were detected for mortalities associated with histomoniasis. Moreover, liver and cecal lesions were not statistically different between the BA and PC groups. Taken together, these data suggest that BA was not efficacious in the prevention or reduction of histomoniasis disease severity when provided at 0.2% dietary concentration under these experimental conditions.

In the United States, non-typhoidal Salmonella causes over one million foodborne infections every year and turkey meat contaminated with Salmonella has been associated from the farm to the processing plant. These outbreaks emphasize efforts on decreasing and preventing human illness associated with live poultry contact through comprehensive interventions from \farm-to-fork" levels. This review article revises the role of the turkey upper respiratory tract, which is now known to play a crucial role in colonization and as a source of contamination, for this remarkable bacterium that has co-evolved to infect plants and animals. Because agriculture represents over 60% of the economy of the state of Arkansas, the mission of our laboratory over the last 21 years has been directed to evaluate and develop applied research to help reduce the incidence of Salmonella spp. from commercial turkey operations. A summary of the published research is presented.

No abstract

Histomoniasis is currently a re-emerging disease of major significance for many commercial turkey and broiler breeder production companies because of the unavailability of drugs or vaccines. The protozoa Histomonas meleagridis ( HM ) requires the presence of enteric microflora to promote the disease. The objectives of this research note were to evaluate the effect of dietary administration of sodium chlorate ( SC ) and sodium nitrate ( SN ) in vitro and in vivo for HM prophylaxis in poults. A total of 128 day-of-hatch female poults obtained from a commercial hatchery were wing-tagged and randomly assigned into 1 of 4 experimental groups: negative control ( NC ), positive control, dietary inclusion of SC (3,200 ppm) and SN (500 ppm). Poults from groups SC and SN started on their respective diets on day 12. All groups, except the NC, were challenged with 2 × 10 5 HM on day 19 . Controls were fed a basal diet, identical to the treatment diets but not supplemented with SC or SN. Body weight gain ( BWG ) was determined weekly, starting on day 1 until day 28, and postchallenge morbidity and mortality were recorded. On day 28 of age, all surviving poults were lesion scored for hepatic and cecal lesions. Ceca and distal ileum were collected on day 28 for bacterial recovery on selective media for total aerobic, lactic acid bacteria, or gram-negative bacteria. The addition of SC and SN in the in vitro growth of HM greatly reduced the growth of the protozoa after 20 h of incubation when compared with the control nontreated group ( P < 0.05). However, dietary supplementation of SC and SN had no effect against HM in vivo, as was demonstrated by BWG, the severity of lesions in the liver and ceca or bacterial recovery of treated poults when compared with the positive control group.

No abstract

RESUMO A dislipidemia é um achado comum, porém não determinante, na síndrome metabólica equina (SME). O objetivo do presente trabalho foi caracterizar a dislipidemia em animais obesos com risco de SME. Para isso, 18 éguas foram alocadas em grupos, de acordo com escore corporal (EC) de 1 a 9: no grupo ideal, animais com EC de 4,5 a 5,5 (n= 6), no grupo sobrepeso, com EC de 6 a 7 (n= 6) e no grupo obeso, animais com EC de 7,5 a 9 (n= 6). Coletaram-se amostras de sangue em jejum de concentrado para determinação de triglicerídeos, colesterol total, glicemia e concentração de insulina. Valores preditivos de sensibilidade à insulina (RISQI) e de secreção β-pancreática (MIRG) foram calculados. O grupo obeso apresentou níveis maiores em relação aos outros grupos de triglicerídeos (P=0,001) e acima do ideal em concentrações de colesterol (P=0,012). Não foi observada diferença nas concentrações plasmáticas de glicose (P=0,53), de insulina (P=0,10) ou de RISQI (P=0,46). Houve diferença entre os grupos nos valores de MIRG (P=0,048), tendo o grupo obeso obtido resultados maiores quando comparado com o grupo ideal. O aumento do EC foi associado ao aumento das concentrações plasmáticas de colesterol e triglicerídeos, o que caracteriza um estado de dislipidemia e de elevação da secreção das células β-pancreáticas.