Egg-based typology of local chickens in Kongo Central, Democratic Republic of the Congo: morphometric traits and internal quality assessed using Haugh units
DOI:
https://doi.org/10.59228/rcst.026.v5.i4.357Keywords:
extensive poultry systems, egg freshness, phenotypic diversity, animal genetic resources, local selectionAbstract
Laying performance and egg quality of local chickens remain poorly documented in the Democratic Republic of the Congo despite their importance as animal genetic and socioeconomic resources.To characterize eggs from local hens in Mbanza-Ngungu, Muanda, and Songololo and to establish an exploratory hen typology based on egg morphometric traits and Haugh units.A total of 190 eggs from 38 hens (five eggs per hen) were analyzed. Egg weight, length, width, and thick albumen height were measured; shape index and Haugh units were calculated. Descriptive analyses were performed at the egg level, whereas the main territorial comparisons, principal component analysis, and hierarchical clustering used hen-level means to account for repeated eggs from the same hen.Mean egg weight ranged from 34.13 ± 7.02 g in Songololo to 36.21 ± 6.60 g in Mbanza-Ngungu, with no robust territorial difference at the hen level. Haugh units differed among territories and were highest in Muanda. The first two principal components explained 79.60% of total variance. Two exploratory hen profiles were identified, differentiated mainly by egg size and, secondarily, by Haugh units; cluster separation was moderate and cluster membership was not associated with territory. The observed phenotypic variability provides a preliminary basis for individual-level characterization of local hens. Although eligibility criteria and the general feeding system were described, detailed individual covariates and post-laying conditions were insufficiently documented for adjustment. The typology remains exploratory and does not establish genetic differentiation or justify selection decisions without further validation.
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