Canonical Correlation Analysis Relating Age At First Egg, Bodyweight At First Egg And Weight Of First Egg With Egg Production At Different Periods In A Strain Of Layer Type Chicken Udeh Ifeanyichukwu
Department of Animal Science, Delta State University, Faculty of Agriculture, Asaba Campus, Nigeria
Email: udehifeanyichukwu@ymail.com.
ABSTRACT
The relationship between age at first egg (AFE), bodyweight at first egg (BWFE), Weight of first egg (WFE), with egg numbers recorded at 20 – 28 weeks (EN1), 28 – 35 weeks (EN2) and 35 – 42 weeks (EN3) was evaluated using canonical correlation analysis. Two hundred layers contributed the data used …show more content…
Therefore, WFE could be used as a selection criterion for selecting good performance layers in terms of egg number.
Keywords: Canonical correlation, chicken, egg production, selection INTRODUCTION
Studies have shown that AFE, BWFE and WFE were interrelated in the domestic chicken (Adenowo et al, 1996; Udeh, 2010). Although these interrelated traits are important, the number of eggs produced at different periods in the laying cycle is more important economically. The impact of the aforementioned traits on egg production under the Nigerian environment has not been studied. The relationship between two or more traits is usually measured using correlation analysis. Correlation describes the extent that one variable relates or predict the other variables. Canonical correlation analysis is a multivariate statistical model that establishes the interrelationship between two sets of variables, in addition to quantifying the percentage of variance common to the two groups (Ventura et al, 2011). The procedure looks for relationship between sets …show more content…
The data consists of age at first egg (AFE), bodyweight at first (BWFE), weight of first egg (WFE) and egg numbers produced at 20 – 28 weeks (EN1), 28 – 35 weeks (EN2) and 35 – 42 weeks (EN3). AFE was recorded as the number of days from day old to first egg. BWFE was recorded individually for each bird at onset of lay. WFE was recorded as the average weight of first ten eggs per bird. Egg numbers were recorded on daily bases from onset of lay (20 weeks) to 42 weeks of age. In the canonical correlation analysis, AFE, BWFE and WFE were considered as the first set of variables (Xi) while egg numbers at different periods (EN1, EN2 and EN3) were considered as the second set of variables (Yi). CCA focuses on the correlation between a linear combination of the variables in one set and a linear combination of the variables in another set (Akbas and Takma, 2005). Thus a linear combination of X variables U = a1x1 + a2x2 +.....................+amxm and a linear combination of Y variables V = b1y1 + b2y2 +.................+bmym. The first canonical correlation is the maximum correlation between U and V for all U and V. Subsequent pairs of the correlations between U and V are also maximized subject to the constraint that they are not correlated with any other previous pairs (Johnson and
Department of Animal Science, Delta State University, Faculty of Agriculture, Asaba Campus, Nigeria
Email: udehifeanyichukwu@ymail.com.
ABSTRACT
The relationship between age at first egg (AFE), bodyweight at first egg (BWFE), Weight of first egg (WFE), with egg numbers recorded at 20 – 28 weeks (EN1), 28 – 35 weeks (EN2) and 35 – 42 weeks (EN3) was evaluated using canonical correlation analysis. Two hundred layers contributed the data used …show more content…
Therefore, WFE could be used as a selection criterion for selecting good performance layers in terms of egg number.
Keywords: Canonical correlation, chicken, egg production, selection INTRODUCTION
Studies have shown that AFE, BWFE and WFE were interrelated in the domestic chicken (Adenowo et al, 1996; Udeh, 2010). Although these interrelated traits are important, the number of eggs produced at different periods in the laying cycle is more important economically. The impact of the aforementioned traits on egg production under the Nigerian environment has not been studied. The relationship between two or more traits is usually measured using correlation analysis. Correlation describes the extent that one variable relates or predict the other variables. Canonical correlation analysis is a multivariate statistical model that establishes the interrelationship between two sets of variables, in addition to quantifying the percentage of variance common to the two groups (Ventura et al, 2011). The procedure looks for relationship between sets …show more content…
The data consists of age at first egg (AFE), bodyweight at first (BWFE), weight of first egg (WFE) and egg numbers produced at 20 – 28 weeks (EN1), 28 – 35 weeks (EN2) and 35 – 42 weeks (EN3). AFE was recorded as the number of days from day old to first egg. BWFE was recorded individually for each bird at onset of lay. WFE was recorded as the average weight of first ten eggs per bird. Egg numbers were recorded on daily bases from onset of lay (20 weeks) to 42 weeks of age. In the canonical correlation analysis, AFE, BWFE and WFE were considered as the first set of variables (Xi) while egg numbers at different periods (EN1, EN2 and EN3) were considered as the second set of variables (Yi). CCA focuses on the correlation between a linear combination of the variables in one set and a linear combination of the variables in another set (Akbas and Takma, 2005). Thus a linear combination of X variables U = a1x1 + a2x2 +.....................+amxm and a linear combination of Y variables V = b1y1 + b2y2 +.................+bmym. The first canonical correlation is the maximum correlation between U and V for all U and V. Subsequent pairs of the correlations between U and V are also maximized subject to the constraint that they are not correlated with any other previous pairs (Johnson and