Principal Component Analysis of Body Measurements In Three Strains of Broiler Chicken
This study was conducted to explore the relationship among body measurements in 3 strains of broilers chicken (Arbor Acre, Marshal and Ross) using principal component analysis with the view of identifying those components that define body conformation in broilers. A total of 180 birds were used, 60 per strain. The parameters recorded at 8 weeks of age were body weight, shank length, thigh length, drumstick length, body length, body width, breast width and wing length. Principal component analysis with variance maximizing orthogonal rotation was used to extract the components. Two principal components were extracted in Arbor Acre which explained 65% of the total variation in the original variables. Similarly three principal components each were extracted in Marshal and Ross
strains accounting for 74.76% and 70% of the total variance respectively. Generally, PC1 had the largest share of the total variance and correlated highly with breast width, wing length, thigh length, shank length and body length. PC1 was termed the generalized form of broilers. PC2 had its loadings on drum stick length, breast width, thigh length and wing length while PC3 had positive loading on drumstick length. These components could be used as selection criteria for improving body size of broilers.
Key words: Body parameters, Broilers, Loadings, Variance maximizing rotation.