JOURNAL OF ANIMAL SCIENCE AND VETERINARY MEDICINE
Integrity Research Journals
ISSN: 2536-7099
Model: Open Access/Peer Reviewed
DOI: 10.31248/JASVM
Start Year: 2016
Email: jasvm@integrityresjournals.org
Using functional forms data analysis to assess egg quality characteristics of the West African black mud tortoise (Pelusios castaneus)
https://doi.org/10.31248/JASVM2026.639 | Article Number: 15EE24CF8 | Vol.11 (2) - April 2026
Received Date: 08 February 2026 | Accepted Date: 25 March 2026 | Published Date: 30 April 2026
Authors: Kperegbeyi, J. I.* , Nwadiolu, R. and Ewododhe, A. C. A.
Keywords: regression models., linear function, Breeder, predictor., Egg weight, Haugh unit
This study was conducted to evaluate egg external and internal quality traits of the West African Black Mud Tortoise. A total of Eighty (80) eggs were collected from (Pelusios castaneus). Four model specifications (linear, double-log, semi-log and exponential functions) were evaluated to determine the best-fitting regression of egg weight on various egg traits. The data showed mean values of 18.84±1.24g, 8.02±0.26g, 28.30±2.40mm and 76.13±3.62% for egg weight (EWT), albumen weight (AWT), albumen length (ALT) and haugh unit (HU), respectively. Analysis indicated that mean yolk weight (YWT), yolk height (YHT), yolk width (YWD), yolk index (YI), shell weight (SWT) and shell thickness (STH) were 7.14±0.15g, 2.16±0.03mm, 4.07±0.13mm, 0.44±0.01, 3.68±0.13g and 0.25±0.01mm, respectively. Findings revealed mean egg length (ELT) (33.89±1.14mm), egg width (EWD) (25.79±1.41mm) and egg shape index (ESI) (1.20±0.02). EWT data demonstrated a non-linear trend. Evaluation of fit quality across four functional forms resulted in coefficient of determination (R2) values of 78.68 % (linear), 78.35% (semi-log), 65.80% (double-log), and 71.30% (exponential), respectively, indicating that the linear model provided the strongest fit. AWT was the most significant predictor of EWT. The results indicate that a linear function is the most suitable, providing the best fit for modelling the EWT curve of Pelusios castaneus in this study. In conclusion, data analysis shows that EWT is the key factor influencing egg quality and reproductive performance in Pelusios castaneus.
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