PHENOTYPIC CORRELATION BETWEEN EXERNAL AND INTERNAL EGG QUALITY TRAITS OF PANCAKE TORTOISE (Malacochersus tornieri)

Abstract

Egg external and internal qualities are of major importance to egg industry worldwide. The objective of this study was to examine some issues such as external and internal quality traits of the pancake tortoise eggs in determining the phenotypic traits. A total of 180 eggs from pancake tortoise were collected over a period of 3 months was used for the study. The parameters measured include egg weight (EWT), shell weight (SWT), shell thickness (STH), egg length (ELT), and egg width  (EWD) which was found respectively as 15.84 g, 0.52g, 0.32mm, 4.02cm, 2.79cm as external egg quality traits (EEQTs) and yolk weight (YWT), albumen weight (AWT), yolk colour (YC),  yolk height (YHT),  albumen height (AHT) and yolk diameter (YD) were found respectively as 7.48g, 7.84, 5.46cm, 1.34cm, 0.67cm and 4.28cm for internal egg quality traits (IEQTs). The research shows that positive and significant (p<0.001) correlations were found between EWT and ELT. EWT and SWT, EWD and YC, EWT and YWT. This implies that EWT had direct relationship with AWT, SWT and YWT. Negative significant correlations were also and only observed between EWD and AHT. There was statistically significant (P<0.001) but negative correlation (-0.24) obtained between the AHT and EWD, although a positive significant correlation exists (P<0.001) between YC and EWD, YWT and EWT. As a result of these observations, it was considered possible to use the EWT in determining SWT, AWT and YWT.