APPLICATION OF PRINCIPAL COMPONENT ANALYSIS APPROACH TO EVALUATE BODY WEIGHT AND MORPHOMETRIC TRAITS OF NEW ZEALAND RABBITS BREED IN SEMI-ARID REGION OF NIGERIA

Abstract

This study was conducted to evaluate body weight and morphometric traits of New Zealand rabbits using principal component approach. Data were taken on body weight (BWT), body length (BL), ear length (EL), tail length (TL), heart girth (HG) and abdominal circumference (AC) on individual animals. Data collected were subjected to multivariate statistical analysis using SPSS 20.0 statistical package procedures. The results showed that sex had significant (P<0.05) effect on all the variables
examined, with higher values recorded for female rabbits (1.01 kg, 28.53 cm, 10.53 cm, 8.70 cm, 20.30 cm and 22.28 cm for BWT, BL, EL, TL, HG and AC respectively) while males had lower values (0.80 kg, 26.15 cm, 9.96 cm, 7.99 cm, 18.80 cm and 20.33 cm for BWT, BL, EL, TL, HG and AC respectively). This trend reveals the manifestation of sexual dimorphism among the rabbit breeds in favour of female rabbits. The phenotypic correlation coefficient values (r) between the morphometric traits were all high and positive, ranging from r = 0.406 (between EL and BL) to r = 0.909 (between AC and HG). HG being the most correlated with BWT (r = 0.786) while the lowest correlation was between BWT and EL (r = 0.462). Two principal components (PCs) from the factor analysis of morphometric traits explained about 80.42% of the total variance. PC1 accounted for 64.46% while PC2 accounted for 15.97% of the total variance. Three variables, representing body conformation, loaded highest in PC1. PC1 had the highest contribution (64.46%) to the total variations and it is regarded as body conformation traits. The results revealed that morphometric traits can be used as aids to selection in rabbit genetic improvement programme.