Genetic parameters of linear type traits in Karan-Fries cattle.

摘要

Data on 219 Karan Fries cows of different parities and stage of lactation were collected for 13 type traits using a linear scale (range, 50-99). Stage of lactation significantly influenced (P<0.01) dairy character and rear udder width. Parity affected significantly (P<0.01) foot angle, dairy character, fore udder attachment, rear udder width and udder depth. The overall means for type traits score were: stature (79.77?.88), rear leg side view (80.45?.76), foot angle (76.26?.88), rump width (79.89?.75), rump angle (82.35?.61), chest and body (80.47?.47), dairy character (78.77?.51), fore udder attachment (80.22?.96), rear udder height (82.75?55), rear udder width (80.07?.74), udder depth (82.15?.89), suspensory ligament (86.34?.83) andteat placement (78.29?.95). Heritability estimates of stature, rear leg, rump width, rear udder width and suspensory ligament were 0.49, 0.25, 0.43, 0.58 and 0.23 respectively. Most phenotypic correlations among type traits were low to moderate. Geneticcorrelations were either beyond range or associated with large standard errors. It was concluded that linear type trait scoring can be used for selection.