Path coefficient analysis of body weight and biometric traits in Ouled-Djellal breed

Abstract

Direct and indirect effects of twelve variables ( neck length (nl), body length

(bl), trunk length (trl), pelvis length (pl), hip width (hw), chest size (cs), chest

depth (cd), chest width (cw), height at withers (htw), height at sacrum (hs),

height at back (hb), side depth (sd) on body weight of 347 Ouled-Djellal ewes

were investigated using path analysis. Seven traits were found not to be

important; they were deleted from the full model. So, we ended up with a

reduced model, with five traits only ( bl, cs, cw, htw, sd). Pairewise correlations

between body weight and zoometrical traits ranged from 0.07-0.72. The direct

effects of chest size and body length on body weight prediction were the

strongest (0.50 and 0.44, respectively). Chest width, side depth was positive and

significant, as well. But height at withers was significant but with negative

effect. The optimum multiple regression equation included chest size, body

length, chest width, height at withers and side depth, with a determination

coefficient (R²) of 0.87 and determination coefficient of error of 0.13 These

results obtained in this investigation could help in weight estimation, selection

and breeding programmes.