20.500.12556/RUL-17716 Variance components estimation for type traits in Slovenian Brown Swiss cattle The objective of this study was to estimate genetic parameters for 39 (26 official and 13 new) scored type traits in Slovenian Brown Swiss cattle. Data set included records of 35 386 Brown Swiss cows scored from 2000 to 2011 using method 'System 97'. The studied type traits were scored on scale from 1 to 9 (29 traits), measured by stick or tape (five traits) or expressed in points from 60 to 90 (five traits). Multiple-trait analyses based on three models were used for estimates of genetic parameters. Fixed class effects in the models were: classifier and year of scoring interaction, calving season, and time from calving to scoring. Bodz condition score effect was additionally fitted as linear regression in the second model. The third model included time after milking as fixed class effect instead of condition. Direct additive genetic effect and herd were used in the models as random effects. Estimated heritabilities ranged from 0.13 to 0.46 for frame and from 0.03 to 0.22 for form traits. Low to intermediate heritabilities (from 0.10 to 0.25) were estimated for mammary system traits. The lowest heritability estimates, in range from 0.04 to 0.13, were obtained for foot and leg traits. The variance ratio for herd covered between 0.02 and 0.26 of phenotypic variation. Genetic correlations among type traits ranged from -0.41 between rear legs side view and legs overall to 0.99 between rump height measured by tape and rump height linearly scored for frame traits. High genetic correlations were estimated for the following pairs of traits: rump width measured and rump width linearly scored (0.92), central ligament and central ligament redefined (0.97), body depth measured and body depth linearly scored (0.86). Phenotypic correlations between pairs of traits were similar in direction but smaller in magnitude in comparison to genetic correlations. Measured type traits should be replaced with the scored one since genetic correlations between them were high. The replacement will lead to the same efficient but cheaper scoring system. Cilj študije je bil oceniti genetske parametre za 39 (26 rutinskih in 13 novo definiranih) lastnosti zunanjosti pri slovenski populaciji rjavega goveda. Podatki zajemajo rezultate ocenjevanja zunanjosti 35 386 prvesnic, ocenjenih med letoma 2000 in 2011 po sistemu 97. Proučevane lastnosti zunanjosti so bile ocenjene na skali od 1 do 9 (29 lastnosti), merjene s palico in trakom (5 lastnosti) ali ocenjene na skali od 60 do 90 (5 lastnosti). Za oceno parametrov disperzije so bili uporabljeni trije različni več lastnostni modeli. Sistematski del prvega modela vključuje vplive: ocenjevalec in leto ocenjevanja, sezono telitve in dobo med telitvijo in ocenjevanjem. Drugi modelv ključuje poleg vplivov v prvem modelu še vpliv linearne regresije kondicije, tretji model pa sistematski vpliv časa od zadnje molže do ocenjevanja. Naključni del modelov v vseh primerih vključuje vpliv črede in aditivni vpliv živali. Dednostni deleži za okvir so ocenjeni z vrednostmi med 0,13 in 0,46 in za oblike med 0,03 in 0,22. Za lastnosti vimena se ocenjeni dednostni deleži gibljejo med 0,10 in 0,25. Majhni dednostni deleži so ocenjeni za lastnosti nog, in sicer med 0,04 in 0,13. Velike razlike v deležu fenotipske variance, le ta se giblje med 0,02 in 0,26, so pojasnjene s čredo. Genetske korelacije med lastnostmi zunanjosti se gibljejo med -0,41 (kot skočnega sklepa in skupna ocena za noge) in 0,99 med oceno in meritvijo za višino križa. Visoke genetske korelacije so bile ocenjene med naslednjimi pari lastnosti: ocenjena in merjena širina križa (0,92); nova in stara definicija centralne vezi (0,97); ocenjena in merjena globina telesa (0,86). Fenotipske korelacije so v primerjavi z genetskimi nekoliko nižje na absolutni skali. Glede na visoke korelacije je smiselno, da novo definirane ocenjevane lastnosti nadomestijo ustrezne merjene lastnosti. Na ta način bo selekcija primerljivo učinkovita, za ocenjevanje posamezne živali pa bo potrebno manj časa. cattle breeding Brown Swiss type trais heritability genetic correlations govedo pasme rjava pasma lastnosti zunanjosti dednostni delež genetske korelacije true false false Angleški jezik Slovenski jezik Delo ni kategorizirano 2014-07-11 13:54:51 2014-07-11 13:54:51 2022-05-20 03:45:00 0000-00-00 00:00:00 2012 0 0 Str. 107-115 št. 2 Letn. 100 2012 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 636.2:575 1581-9175 3162248 http://aas.bf.uni-lj.si/zootehnika/100-2012/PDF/100-2012-2-107-115.pdf 1 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=17716 Biotehniška fakulteta 0 0 0