Evidence map›Paper›PMID 42231658›Full record

ArticleJournal of experimental zoology. Part A, Ecological and integrative physiology2026

Effects of Summer Heat Stress on Physiological Parameters and Reproductive Efficiency of Barbarine Ewes Under Natural Outdoor or Indoor Conditions.

Samia Khnissi, Dorra Aouadi, Hela Chalouati, Mourad Rekik, Imène Ben Salem

Abstract read
In one paragraph

Article in Journal of experimental zoology. Part A, Ecological and integrative physiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

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5 · Who and what money

Authors and funding

5 authors.

Samia KhnissiLaboratory of Animal and Forage Production, National Institute of Agronomic Research of Tunisia, University of Carthage, Tunis, Tunisia.ORCID https://orcid.org/0000-0002-5277-3262
Dorra AouadiLaboratory of Animal and Forage Production, National Institute of Agronomic Research of Tunisia, University of Carthage, Tunis, Tunisia.
Hela ChalouatiLaboratory of Animal and Forage Production, National Institute of Agronomic Research of Tunisia, University of Carthage, Tunis, Tunisia.ORCID https://orcid.org/0000-0001-6123-0334
Mourad RekikInternational Center for Agricultural Research in the Dry Areas (ICARDA), Tunis, Tunisia.
Imène Ben SalemDepartment of Animal Production, Service of Zootechnics and Agricultural Economy, National School of Veterinary Medicine Sidi Thabet, University of Manouba, La Manouba, Tunisia.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Climate change and rising ambient temperatures increasingly challenge sheep production systems in arid and semi-arid regions, particularly during the summer breeding season. This study evaluated the effects of heat stress and direct solar exposure on physiological responses, metabolic profile, and reproductive performance of Barbarine ewes, a fat-tailed breed adapted to harsh environments. A total of 112 non-lactating multiparous ewes were allocated to two groups during summer mating: an indoor group protected from solar radiation (IDGp; n = 58) and an outdoor group exposed to direct sunlight (ODGp; n = 54). Both groups experienced severe to extreme heat stress for more than 65% of the experimental period. Sun exposure significantly increased rectal temperature (+0.2 to +0.6°C), respiratory rate (up to 130 vs 61 breaths/min), and heart rate (up to 95 vs 87 beats/min) in outdoor ewes (ODGp) compared to indoor ewes (IDGp), indicating a higher physiological heat load in sun-exposed animals. The temperature-humidity index (THI) remained comparable between groups (≈24.7), suggesting comparable THI values. Metabolic responses were characterized by increased plasma concentrations of triglycerides (+36%), total proteins (+7.5%), urea (+13%), creatinine (+34%), and potassium (+5%), along with a decrease in cholesterol levels (-15%) in ODGp compared to IDGp. Despite these physiological and metabolic adjustments, body condition score and live weight were maintained in both groups. Reproductive performance was not affected by solar exposure, with estrus occurrence exceeding 94%, an ovulation rate of 1.17, and no significant differences in fertility (79.3% vs 77.8%), prolificacy, or fecundity between groups. These findings indicate that, although direct solar radiation increases physiological strain, it does not impair reproductive function under comparable ambient thermal conditions. Barbarine ewes thus exhibit strong functional resilience to heat stress, highlighting their suitability for extensive production systems in hot and dry environments.

Indexed as

Heat-Shock ResponseSheepAnimal HusbandryAnimalsBody TemperatureEnvironmental ExposureFemaleHeart RateHot TemperatureRespiratory RateSeasonsStress, PhysiologicalSunlightBarbarine ewesheat stressphysiological responsesreproductive performancesummer breedingTHI

Identifiers

PMID42231658
PMCPMC13353757

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.