Evidence map›Paper›PMID 41887174›Full record

SynthesisPoultry science2026

Grapes and their by-products effects on growth performance, intestinal histomorphology, immune response and antioxidant status in broiler chickens - A meta-analysis.

Roshan Riaz, Muhammad Waqas, Hafiz Muhammad Nouman, Beenish Imtiaz, Rania Ali El Hadi Mohamed, Hira Maqsood, Zaheer Mehmood, Adam Cieślak, Lixian Liu, Chanjuan Zhao

Abstract readMeta-Analysis
In one paragraph

Synthesis in Poultry science, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
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

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

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

3 citing papers in PubMed.

  1. Article
  2. Article
  3. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors.

Roshan RiazDepartment of Animal Nutrition and Nutritional Diseases, Faculty of Veterinary Medicine, Kafkas University, Kars 36100, Türkiye. Electronic address: roshan.riaz@kafkas.edu.tr.
Muhammad WaqasDepartment of Poultry Production, Faculty of Animal Production and Technology, University of Veterinary and Animal Sciences, Lahore 54000, Pakistan.
Hafiz Muhammad NoumanDepartment of Animal Nutrition and Nutritional Diseases, Faculty of Veterinary Medicine, Selçuk University, Konya, 42130, Türkiye.
Beenish ImtiazDepartment of Animal Nutrition and Nutritional Disease, Faculty of Veterinary Medicine, Atatürk University, Erzurum 25240, Türkiye.
Rania Ali El Hadi MohamedDepartment of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
Hira MaqsoodDepartment of Zoology, University of Management and Technology, Lahore 54770, Pakistan.
Zaheer MehmoodMHP Desert Hills Poultry Co., P.O Box 12341, Riyadh, 4253, Saudi Arabia.
Adam CieślakDepartment of Animal Nutrition, Poznań University of Life Sciences, Wołyńska 33, Poznań 60-637, Poland.
Lixian LiuInstitute of Science and Technology, Chuxiong Normal University, Chuxiong 675000, Yunnan, China. Electronic address: liulixian@cxtc.edu.cn.
Chanjuan ZhaoChongqing Three Gorges Vocational College, Wanzhou, Chongqing 404155, China. Electronic address: 2005060034@cqsxzy.edu.cn.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

A comprehensive meta-analysis was conducted to quantitatively assess the impact of dietary grape and grape by-products supplementation on growth performance, intestinal histomorphology, immunological response, and antioxidant status in broiler chickens. A systematic search guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 across PubMed, Scopus, and Web of Science up to October 19, 2025, yielded 349 records, of which 21 controlled feeding studies satisfied the inclusion criteria. Data were analyzed using a multilevel random-effects model in R (metafor package). Heterogeneity (I² and τ²) and publication bias were evaluated using Egger's regression and the trim-and-fill method. Pooled estimations indicated that grape supplementation did not significantly influence body weight gain (mean difference (MD) 12.7 g, 95% CI: -14.5 to 39.8, P = 0.360), feed intake (MD = 30.6 g, 95% CI: -51.8 to 113, P = 0.466), or feed conversion ratio (FCR) (MD = 0.01, 95% CI: -0.01 to 0.02, P = 0.565). Significant enhancements were observed in villus height (MD = 59.5 µm, 95% CI: 1.49-117, P = 0.044), reduction in crypt depth (MD = -13.3 µm, 95% CI: -18.7 to -7.95, P < 0.001), and villus height-to-crypt depth ratio (VH:CD) (MD = 1.31, 95% CI: 0.32-2.29, P = 0.009), indicating improved intestinal histomorphology and absorptive capacity. The humoral immune response showed a positive but non-significant effect (standardized mean difference (SMD) = 1.09, 95% CI: -0.69-2.87, P = 0.228). Enzymatic antioxidants (SMD = 0.25, P = 0.697), lipid peroxidation (SMD = -0.50, P = 0.297), and non-enzymatic antioxidant capacity (SMD = 2.45, P = 0.26) were also non-significant. Substantial heterogeneity across outcomes was mainly explained by grape product form, intestinal segment, immunological outcome type, and antioxidant marker type through meta-regression. Overall, grape by-products improved intestinal histomorphology but did not significantly enhance growth performance, immunity, or oxidative balance.

Indexed as

AntioxidantsChickensImmunity, InnateIntestinesVitisAnimal FeedAnimal Nutritional Physiological PhenomenaAnimalsDietDietary SupplementsAntioxidantsAntioxidant statusBroilerGrape by-productsGrowth performanceIntestinal histomorphology

Identifiers

PMID41887174
PMCPMC13053995

What Socratic holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

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 Socratic graph.