The aim of this study was to analyze the non-genetic fixed effects affecting 14 linear type traits and an overall score recorded on 4,385 Italian Heavy Draught Horse adults (IHDH; 3,772 females and 613 males) scored by 29 classifiers in 20 years of evaluation (i.e. 1992-2011). Animals were scored with a 9 point scale system (1-5 including half points) at about 3 years of age. Data were analyzed by ANOVA to evaluate the magnitude of three non-genetic fixed effects: stud-year of evaluation-classifier (SYC; 1,325 levels), sex (2 levels), age at evaluation (AC; 5 classes, i.e., ≤27, 28, 29-32, 33-47, and ≥48 months of age). The R-square of model for all analyzed traits ranged from 0.38 to 0.57, with lower values for fore feet and greater values for frame size. The SYC resulted the effect of greater magnitude and in all traits adsorbed a significant amount of variation. Sex differentiated mainly frame size, fleshiness, bone incidence, fore diameters and upper line direction, indicating a significant aspects between males and females as regard the meat production characteristics of the breed. The AC influenced significantly frame size, fleshiness, thorax depth, fore diameters, rear diameters and the overall score. It is concluded that all potential source of variation need to be taken into account in the analysis of data from linear type evaluation of adult IHDH.

Italian heavy draught horse; linear type traits; source or variation; ANOVA

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia