Principal component analysis of body measurements of bulls of local cattle of Manipur, India

Abstract

Biometric traits (height at withers, body length, heart girth, paunch girth, ear length, tail length, switch length, neck
girth, neck length, head length, distance of horn at base, circumference of horn at base, length of horn, hind leg length
and fore leg length) in 107 bulls of Manipuri local cattle were recorded from Imphal valley of Manipur, India and
analyzed by principal component analysis to explain body conformation. The average of these traits indicated that this
local cow is a smaller type of cattle breed. Factor analysis with promax rotation revealed 6 factors which explained
about 69.77% of the total variation. Factor 1 described the general body conformation and explained 21.93% of total
variation. It was represented by significant positive high loading of height at wither, body length, heart girth, paunch
girth and ear length. The communality ranged from 0.493 (elbow length) to 0.782 (neck girth) and unique factors
ranged from 0.507 to 0.218 for all these 18 different biometric traits. The result suggested that principal component analysis (PCA) could be used in breeding programs with a drastic reduction in the number of biometric traits to be recorded to explain body conformation.