Evidence map›Paper›PMID 41880929›Full record

ArticlePoultry science2026

Estimating genetic parameters of egg production in three local Tanzanian chicken ecotypes.

T Magwaba, J C M Dekkers, S J Lamont, A Wolc, E Mollel, J R Mushi, M Walugembe, E N Amuzu-Aweh, G H Chiwanga, N Chouicha and 5 more

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In one paragraph

Article in Poultry science, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
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

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

0 citing papers in PubMed.

No citing paper in PubMed yet.

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

15 authors.

T MagwabaIowa State University, Ames, IA 50011, USA.
J C M DekkersIowa State University, Ames, IA 50011, USA.
S J LamontIowa State University, Ames, IA 50011, USA.
A WolcIowa State University, Ames, IA 50011, USA; Hy-Line International, Dallas Center, IA 50063, USA.
E MollelSokoine University, P.O. Box 3000, Chuo Kikuu, Morogoro, Tanzania.
J R MushiSokoine University, P.O. Box 3000, Chuo Kikuu, Morogoro, Tanzania.
M WalugembeIowa State University, Ames, IA 50011, USA.
E N Amuzu-AwehUniversity of Ghana, P.O. Box L.G. 25, Legon, Accra, Ghana.
G H ChiwangaSokoine University, P.O. Box 3000, Chuo Kikuu, Morogoro, Tanzania.
N ChouichaDepartment of Animal Science, University of California, Davis One Shields Avenue, Davis, CA 95616, USA.
P L MsoffeSokoine University, P.O. Box 3000, Chuo Kikuu, Morogoro, Tanzania.
T KellyDepartment of Animal Science, University of California, Davis One Shields Avenue, Davis, CA 95616, USA.
R A GallardoDepartment of Animal Science, University of California, Davis One Shields Avenue, Davis, CA 95616, USA.
A P MuhairwaSokoine University, P.O. Box 3000, Chuo Kikuu, Morogoro, Tanzania.
H ZhouDepartment of Animal Science, University of California, Davis One Shields Avenue, Davis, CA 95616, USA. Electronic address: hzhou@ucdavis.edu.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Indigenous chickens (ICs) play a crucial role in ensuring food security, generating income, and supporting livelihoods in many developing countries. Despite their importance, ICs typically exhibit low productivity, particularly in egg production. Understanding their genetic potential is essential for developing sustainable breeding strategies. This study estimated genetic parameters for egg production and egg weight traits in three Tanzanian IC ecotypes: Ching'wekwe (n = 171), Kuchi (n = 220), and Morogoro Medium (n = 406). Birds from 13 hatches were raised under improved conditions, and egg production data were collected across six consecutive 90-day periods (EP1 to EP6), beginning at the age of first egg (AFE; mean = 164 ± 15.5 days). Laying status (LAY) was defined per period, with LAY = 1 if >3 eggs were laid and LAY = 0 otherwise. Additional egg production traits included average clutch length (ACL), number of eggs per clutch (EPC), and inter-clutch pause (ICP). The average annual egg production was 52.1 eggs per hen, and mean egg weight (EW) was 43.1 ± 5.5 g, peaking in EP5. Ecotype significantly affected most EW traits, with Kuchi hens laying the heaviest eggs and showing shorter clutch lengths and pauses (p < 0.05). Heritability estimates ranged from 0.1 to 0.6 for EP, from 0.1 to 0.4 for EW, from 0.1 to 0.2 for clutch traits, and from 0.1 to 0.3 for LAY. Genetic correlations between egg production in different periods were mainly positive (average: 0.38), and those among EW traits in various periods were strong and positive (average: 0.80). Clutch traits showed mixed or weak genetic correlations. Despite low productivity, the observed moderate heritabilities and positive genetic correlations between periods suggest scope for selection-based improvement. However, some unfavorable genetic correlations and age-related variability highlight the need for flexible, multi-trait selection strategies to balance production traits over time.

Indexed as

ChickensOvipositionOvumReproductionAnimalsEcotypeFemaleTanzaniaClutchEgg productionGenetic parameterHeritabilityIndigenous chicken

Identifiers

PMID41880929
PMCPMC13045676

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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.