Fattening and slaughter traits of Large Yorkshire

Abstract

In this paper, results of the investigation of fattening and slaughter traits of Large Yorkshire (250 fattening pigs) are presented. The investigation started as piglets reached average body mass of 25 kg, and ended as they reached body mass of 100 kg, followed by slaughtering. Fattening pigs were fed standard complete mixtures in farm conditions. Slaughtering of animals was carried out in 'Bek' slaughterhouse in Zrenjanin. Following fattening traits were investigated: age and weight at slaughtering, daily gain and feed conversion, as well as following carcass side traits: length of carcass side, backfat thickness on shoulder, mid back and loin, weight of ham and weight of shoulder, weight of meat with bones, weight of fat with skin and their ratio. Also heritability of major fattening traits as well as phenotypic correlation of fattening traits and carcass side quality were established. Obtained data was processed by method of least squares (LSM LMW - Harvey, 1987). Based on obtained results, average age at slaughtering of 181,45 days, as a consequence of high daily gain of 712,01 g, was established. Favorable mean values of fattening traits with considerably low relative deviation indicated good genetic potentials of the investigated population. These results indicate that it is possible to considerably improve fattening traits in view of their economical value, in large scale production. With average length of carcass sides of 97,60 cm, established backfat thickness (back and loin) was 26,3 and 35,8 mm respectively, and lean fat ratio 1,59. Average results of the analysis of carcass side and yield of certain body parts of the investigated breed are satisfactory. Heritability coefficients of investigated traits were high and varied from 0,511 to 0,651. Also, the evaluated value of the heritability coefficient was somewhat higher in case of DG and FC. Investigated coefficients were positive, which provided positive selection effects in attempt to improve these traits by selection. The highest phenotypic correlation was demonstrated between DG and AS, as well as RMF and WFS (-0,762**, -0,687**). Backfat thickness is in correlation with feed conversion and length of carcass side. The correlation value varies from very low to low. Phenotypic correlation of BT and FC was positive low, statistically significant and highly significant, negative correlation was established in case of BT and CSL. Based on results of the investigation it can be concluded that average phenotypic expression and variability of fattening traits of pigs from the investigated population are satisfactory. Heritability coefficients of investigated traits were high.