Genetic Parameters of Some Conformational Traits in Iraqi Arabian Horses

Abstract

Abstract This study is conducted in a private farms in Al-Diwania and Al-Najaf Provinces by using 46 progenies(both 28 males and 18 females) belong to 5 stallions. Their ages ranged from less than 2 years to 6 years and over at the time of measurements, 14 morphological traits are taken: Withers height(WH) After withers height (AWH)Croup height (CH), Middle back height (MBH), Hip height (HH) Buttock height(BH) Dock height(DH) Body length(BL), Scapula length(SL), Arm length (AL), Croup length (CL), Shoulder joint angle (SJA), Elbow joint angle (EJA) and Croup angle(CA). All conformational trait measuremens have been collected between March and June( 2019) by the same trained qualifier using a horse measuring stick, and goniometer. The results obtained of the current study can be summarized as follow :The females are significantly (P ≤ 0.05) higher than males in WH, MBH, BL, CL and CA measurements. Generally all measurements of females are higher than males. The results indicate there are highly significant (P ≤ 0.01) effect of age on all body measurements of horses, the horses of age 6 years and over have inquired higher measurements comparison with other ages. The horses with age less than two years have lowest measurements. The means of body measurement for horses with 6 years and over are 142-88 (WH), 141.04 (AWH), 144.6 (CH), 140.69 (MBH), 139.11 (HH), 135.54 (BH), 138.11 (DH), 156.11 (BL), 52.69 (SL), 43.50 (AL), 38.77 (SL), SJA (47.38), EJA (34.54) and CA (47.69) respectively. The results appear that the sires had an important source of variation, there are significant differences between the different body measurements of the sire’s sons the estimates of heritability ranged from 0.002 for SL to 0.80 for BL. The highest value of heritability for BL is (0.80), CH (0.74), EJA (0.7) and is (0.52) for WH, The values of genetic and phenotypic correlations are highly significant (P ≤ 0.01) and ranged from (0.40-0.97) and from (0.41-0.99). Simple correlation coefficients are found between BL and WH, BL and CH and WH and CH which are 0.735, 0.717, 0.907 and 0.69, 0.69 and 0.91 respectively. The highest breeding value is 2.932 for the BL and the lowest is -4.606 for BH.