Stepwise canonical discriminant analysis of quantitative traits was performed
to characterize Arbor Acre (n = 29), Marshall (n = 29) and Ross 308 (n = 30)
strains of broiler chicken at two weeks of age. Average body weight of
322.11 ? 51.33 g, 310.70 ? 51.20 g and 310.24 ? 42.37 g were obtained for
Arbor Acre, Marshall and Ross 308 strains, respectively. Correlation
coefficients between traits was positive (0.13-0.80). Out of the eight
traits used, shank length (SL), body length (BL), wing length (WL), breast
girth (BG) and thigh circumference (TC) were selected by stepwise procedure
as discriminating variables with respective tolerance of 0.75, 0.84, 0.86,
0.57 and 0.66. The Mahalanobis distance indicated that Arbor Acre and
Marshall were closely related by SL (2.006), WL (5.704), BG (6.002) and TC
(6.314) while Arbor Acre and Ross 308 were related by BL (4.212). Two
canonical discriminant functions were generated. Function 1, with smaller
Wilk's Lambda (0.15), stronger canonical correlation coefficient (0.88),
highly significant Chi-square (p<0.0001), greater eigenvalue (3.14) and
percentage variance (87.28%), possessed higher discriminatory power than
function 2.72.4%, 82.8% and 90.0% of the cross validated cases were
correctly classified as Arbor Acre, Marshall and Ross broilers,
respectively. The study revealed that Ross 308 was genetically distinct from
Arbor Acre and Marshall, which were more closely related, using shank
length, body length, wing length, breast girth and thigh circumference as
discriminating traits. Stepwise canonical discriminant analysis is therefore
relevant in classification genetics.