Managing Colllinearity in Modeling the Effect of Age in the Prediction of Egg Components of Laying Hens Using Stepwise and Ridge Regression Analysis

Abstract

The relationships between egg measurements [egg weight (EGWT), egg width (EGWD), egg shape index (EGSI), egg volume (EGV) and egg density (EGD)], and egg components [eggshell (SWT), yolk (YWT) and albumen (AWT)] were investigated in laying hens with 32, 45, and 59 weeks of age with an objective of managing multicollinearity (MC), using stepwise regression (SR) and ridge regression (RR) analyses.There were significant correlations among egg traits that led to MC problems in all eggs. Hen age influenced egg characteristics and the magnitude of the correlations among egg characteristics. Eggs produced at older age had significantly (p<0.01) higher EGWT, EGWD, EGV, YWT and AWT than those produced at younger age. The SR model alleviated MC problem in eggs produced at 32 weeks, with condition index greater than 30, and one predictor, EGWT had a model fit predicted egg components with R 2 ranged from 60 to 99%. The SR model of eggs produced at 45 and 59 weeks indicated MC problem with variance inflation factors (VIF) values greater than 10, and 4 predictors; EGWT, EGWD, EGV and EGD had a model fit that significantly predicted egg components with R 2 % ranged from 76 to 99 %. The RR analysis provided lower VIF values than 10 and eliminated the MC problem for eggs produced at any age group.It is concluded that the RR analysis provided an ideal solution for managing the MC problem and successfully predicting egg components of laying hens from egg measurements.

Phenotypic Correlations Between Egg Quality Traits Amid the Laying Phase of Broiler Breeder Hens

“…The coefficients of phenotypic correlations between the internal and external egg quality traits considered are shown in Table 4. A significant positive correlation (p < 0.01) was found between the egg weight and both the yolk weight (0.60) and albumen weight (0.91), which is consistent with the results of most studies (Suk & Park, 2001;Wolanski et al, 2007;Moula et al, 2010;Debnath & Ghosh, 2015;Shafey et al, 2015;Kgwatalala et al, 2016;Molnár et al, 2016;Ahmadu et al, 2018). Furthermore, the egg weight was found negatively correlated (p < 0.05) with the yolk ratio (-0.20) and positively correlated with the albumen ratio (0.25), which is also consistent with the results of a number of studies (Olawumi & Ogunlade, 2008;Moula et al, 2010;Debnath & Ghosh, 2015;Shafey et al, 2015;Inca et al, 2020).…”

“…Moreover, a positive correlation between egg weight and shell weight has also been reported in numerous studies (Suk & Park, 2001;Wolanski et al, 2007;Moula et al, 2010;Shafey et al, 2015;Molnár et al, 2016;Sirri et al, 2018;Inca et al, 2020). The established absence of significant correlation between egg weight and shape index is consistent with the results of Şekeroğlu & Altuntaş (2009), Shafey et al (2015), Kgwatalala et al (2016), and Ukwu et al (2017). The positive correlation found by Moula et al (2010) stands in contrast to the negative correlation reported by Debnath & Ghosh (2015) and Inca et al (2020).…”

“…A significant positive correlation between egg weight and egg length and width has been confirmed in a number of previous studies (Moula et al, 2010;Kgwatalala et al, 2016;Ukwu et al, 2017;Ahmadu et al, 2018;Inca et al, 2020). Moreover, a positive correlation between egg weight and shell weight has also been reported in numerous studies (Suk & Park, 2001;Wolanski et al, 2007;Moula et al, 2010;Shafey et al, 2015;Molnár et al, 2016;Sirri et al, 2018;Inca et al, 2020). The established absence of significant correlation between egg weight and shape index is consistent with the results of Şekeroğlu & Altuntaş (2009), Shafey et al (2015), Kgwatalala et al (2016), and Ukwu et al (2017).…”

“…Olawumi & Ogunlade (2008) found a significant correlation between almost all internal egg quality traits and egg weight in one commercial layer breed. The existence of collinearity in the assessment of basic parts of eggs from broiler breeders (namely egg weight, length, width, and egg shape index) was evaluated by Shafey et al (2015). Differences in egg quality and correlations between egg quality traits in the maternal and paternal strains of layer breeds was examined by Ahmadu et al (2018).…”

Organic trace minerals on productive performance, egg quality and immune response in Bovans White laying hens

“…Shell problems tend to occur in mature birds and have been associated with increased in size and decreased in shell quality (Shafey, Hussein, Mahmoud, Abouheif, & Al-Batshan, 2015;Xiao et al, 2015). It is also known that the activity of the 25-hydroxycholecalciferol-1-hydroxylase enzyme decreases and therefore, calcium absorption (Joyner, Peddie, & Taylor, 1987;Xiao et al, 2014).…”