Direct and Indirect Effects of Egg Quality Traits on Egg Weight of Potchefstroom Koekoek Chicken Genotype

Abstract

Path analysis is the statistical tool used to assess the direct and indirect effects of independent variables on the dependent variables. This study was done to examine the association among egg weight (EWt) and egg quality traits, including egg length (EL), egg width (EWD), yolk weight (YW), shell weight (SW), shell ratio (SR), shell index (SI), albumen weight (AW), albumen ratio (AR) and yolk ratio (YR), and assess the direct and indirect influences of egg quality traits on egg weight. Three hundred eggs of Potchefstroom Koekoek chicken genotype were used in the study to determine egg weight and egg quality traits. Pearson’s association and path coefficient analysis were utilised for analysing data. The findings of association showed that EWt had positively high statistically significant association (P<0.01) with EL (r=0.79), EWD (r=0.55), YW (r=0.45), AW (r=0.48), and AR (r=0.38). Path analysis results revealed that YR (-1.98) followed by YW (1.72) made the biggest direct influence on the EWt, while AR followed by SW displayed the highest indirect effect on EWt via YR and YW. Correlation findings recommend that improving EL, EWD, YW, AW and AR might result in increased EWt. The results of path analysis indicate that YR and YW could be selected during breeding to improve EWt of Potchefstroom Koekoek chicken genotype. Chicken farmers may use the outcomes of the current study to predict EWt using egg quality traits.