Authors analysed field test data (collected and owned by the National Institute for Agricultural Quality Control between 1994-1999) of various pig breeds (Belgian Landrace, Duroc, Pietrain), and constructions (Duroc × Belgian Landrace, Belgian Landrace × Hampshire, Pietrain × Hampshire, Pietrain × Duroc, the D and E-lines of the Ka-Hyb hybrid pig). Gilts are kept in groups up to 25 pigs while boars are raised in smaller groups up to 15 on an ad libitum feeding regime. In the field test three ultrasonic back fat measurements are taken from boars and gilts between 80 and 110 kg at the middle of the spinal chord (shoulder, mid-back, loin). Average back fat thickness is calculated as the average of these three measurements. Heritability of average back fat depth was estimated using the REML method. The estimates varied between 0.12-0.51 depending on the genotype. The existence of genetic ties between the herds of the various pig populations was measured through the use of boars across the herds. Concerning the Belgian Landrace breed and the E-line of the Ka-Hyb hybrid pig no genetic ties were found, which means that the boars of these populations were only used within the herds. On the other hand week connections (5-14%) were found for the other genotypes. Boars having been used in two or more herds showed more reliable breeding values (lower prediction error variance) than those animals, which had progeny in one herd only. Based on the results authors suggested the exclusive application of the BLUP method in the Hungarian pig evaluation.

Pig; heritability; REML method

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