Heritability, phenotypic and genetic correlations of the growth intensity and meat yield of pigs

Abstract

The five year study included two genotypes of gilts of performance tested gilts, Swedish landrace and crosses F1 generation SLxLY. Of total number (n=3600), 1709 animals were genotype SL and 1891 animals were genotype SLxLY. Measuring of back fat thickness in the loin part (FT1), between 3rd and 4th lumbar vertebrae, 7cm laterally to the back line; back fat thickness (FT2) and depth of the musculus longissimus dorsi (MLD) between the 3rd and 4th rib from the rear, 7cm laterally to the back line. Assessment of meat yield was done using the ultrasonograph apparatus Piglog 105. In regard to meat yield indicators, medium heritability values were established for FT1 h2=0.461, and high values for FT2 h2=0.639, and for meat yield h2=0.633. Low heritability was established for depth of MLD (h2=0.105), life daily gain (h2=0.110) and age at the end of test (h2=0.103). Established phenotypic correlations between fat thickness FT1 and FT2 were strong (rp=0.638); between fat thickness and meat yield very strong (rp=-0.880 to -0.895), and between fat thickness and MLD very weak and negative (rg=-0.103 to -0.216). Genetic correlations were stronger than phenotypic, so between fat thickness FT1 and FT2 the correlation was complete/full (rg=0.930), also between fat thickness and meat yield (rg=-0.979 to -0.982), whereas the correlation between fat thickness and MLD was strong and negative (rg=-0.627 to -0.653). Heritability values for fat thickness and meat yield show that these traits have high level of heritability and are transfered to the progeny, whereas the level and strength of their dependance show that by decreasing the fat thickness positive influences is exhibited on meat yield, and that by increasing of depth of MLD also the meat yield is increased.

Petogodišnjim istraživanjem su bila obuhvaćena dva genotipa nazimica švedski landras i melezi F1 generacije ŠLxVJ. Od ukupnog broja (n=3600) istraživanjem je obuhvaćeno 1709 grla genotipa ŠL i 1891 grla genotipa ŠLxVJ. Merenje debljine leđne slanine i dubine musculus longissimus dorsi (MLD) i procena mesnatosti je obavljeno ultrazvučnim aparatom Piglog 105. Za pokazatelje mesnatosti utvrđeni su srednji heritabiliteti za SL1 h2=0,461, a visoki za SL2 h2=0,639, i za mesnatost h2=0,633. Nizak heritabilitet utvrđen je za dubinu MLD-a (h2=0,105), životni dnevni prirast (h2=0,110) i za uzrast (h2=0,103). Utvrđene fenotipske korelacije između debljine slanine SL1 i SL2 su jake (rp=0,638); između debljine slanine i mesnatosti korelacije su vrlo jake (rp=-0,880 do -0,895), dok su između debljine slanine i MLD-a jako slabe i negativne (rg=-0,103 do -0,216). Genetske korelacije su jače od fenotipskih, tako da je između debljine slanine korelacija potpuna (rg=0,930), kao i između debljine slanine i mesnatosti (rg=-0,979 do -0,982), dok je korelacija jaka i negativna između debljine slanine i MLD-a (rg=-0,627 do -0,653). PR Projekat Ministarstva nauke Republike Srbije, br. TR 31081.