Related Experiment Video
Updated: Aug 8, 2025

Probing the Limits of Egg Recognition Using Egg Rejection Experiments Along Phenotypic Gradients
Published on: August 22, 2018
Genetic and phenotypic parameter estimates for selection within Ugandan indigenous chickens
Geoffrey Akiiki Beyihayo1, Donald Rugira Kugonza2, Elly K Ndyomugyenyi3
1Department of Animal Production and Range Management, Gulu University, Gulu, Uganda. beyigeo@gmail.com.
Abstract:
The high genetic variation within indigenous chickens (IC) which provides an opportunity to select superior stock for sustainable production and conservation is under-exploited. This study is aimed at estimating heritability and genetic and phenotypic correlation coefficients of productive and reproductive traits of Ugandan IC as a basis for selection. Data on traits were collected across two consecutive generations, weight (W) and shank length (SL) of chicks at hatching (HW) as well as at 2 (W2; SL2), 4 (W4; SL4), 6 (W6; SL6), 8 (W8; SL8), and 12 (W12; SL12) weeks of growth. Body weights at onset of lay (WFE) were also measured. In addition, egg number (EN-60), egg weight (EW), clutch number (CLN-60), and clutch size (CLS-60) over a period of 60 days were recorded. Genetic parameters were estimated using the univariate animal model analysis with restricted maximum likelihood procedure using the variability package of R, version 4.1.1. Heritability of traits ranged from 0.30 and 0.72 except SL4 (0.02), SL12 (0.14), and EN-60 (0.17). The traits EN-60 and W4 were negatively phenotypically correlated (- 0.49). Body weight at first egg was highly genetically correlated (0.99) with SL8. Egg number was significantly, negatively, and genetically correlated (- 0.96) with SL12. In conclusion, shank length is a potential phenotypic marker when selecting for live weight at onset of lay and egg yield. The shank length could, therefore, permit selection of superior chickens at an early age.
Related Concept Videos
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
Types of Selection
Frequency-dependent Selection
Genetics of Speciation
Limits to Natural Selection
Complementation Tests
Organisms heterozygous for different mutations are crossed pairwise in all combinations. If present on different genes, the mutations can complement each other by providing the missing...

