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

Autor:	Ruff J; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Barros TL; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Tellez G Jr; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Blankenship J; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Lester H; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Graham BD; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Selby CAM; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Vuong CN; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Dridi S; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Greene ES; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Hernandez-Velasco X; Departamento de Medicina y Zootecnia de Aves, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autonoma de Mexico, Ciudad de Mexico 04510, Mexico., Hargis BM; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA., Tellez-Isaias G; Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA. Electronic address: gtellez@uark.edu.
Jazyk:	angličtina
Zdroj:	Poultry science [Poult Sci] 2020 Mar; Vol. 99 (3), pp. 1687-1692. Date of Electronic Publication: 2019 Dec 27.
DOI:	10.1016/j.psj.2019.10.075
Abstrakt:	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. (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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