The objective of this paper was an estimation of genetic parameters for carcass weight, conformation, fatness class and net gain for Simmental cattle in Croatia. Data of young bulls slaughtered in ...years 2005 and 2006 with 12 to 24 months of age was taken from the central database of the Croatian Livestock Centre. Three data sets were constructed as follows: 1) data set 1 (DS1) included 80462 records of bulls with known and unknown parents; 2) data set 2 (DS2) had 26245 records of bulls with at least one known parents; 3) data set 3 (DS3) with 6272 records of bulls slaughtered between 12 and 14 months of age. Pedigree for DS1 included a total of 118595 animals, 70415 animals and 19319 animals in pedigree for DS2 and DS3, respectively. Variance components were estimated by REML method as implemented in the VCE-5 program package. Statistical model included region, calving season, abattoir-supervisor interaction as fixed class effects and slaughter age as quadratic regression. Direct additive genetic effect was included in the model as random effect. For carcass weight heritability estimates were 0.10 ± 0.006, 0.13 ± 0.02 and 0.11 ± 0.03 for DS1, DS2 and DS3, respectively. Heritability estimates for net gain were 0.09 ± 0.006, 0.16 ± 0.03 and 0.13 ± 0.03, and for carcass conformation were 0.05 ± 0.006, 0.03 ± 0.01 and 0.05 ± 0.006 for DS1, DS2 and DS3, respectively. Results attained indicate that DS2 can be used for genetic evaluation of the Simmental carcass traits in Croatia. However, in the future more improvement should be done, concerning the constitution of contemporary groups, and special attention should be given to data collection.
The objective of the study was to evaluate genotype by environment interaction (GxEI) for yield traits in Holstein, Simmental and Brown breed cattle in Slovenia using multiple trait analysis. Data ...from Slovenian milk-recording scheme was used. The lactation records on cows having first to third calving in the period 1990-2004 and milk, protein and fat yield in 305 days were studied. The variables used to characterize the environment were herd-year averages of each trait. The multiple trait analysis was done using the highest and lowest quartiles of the environments. To study the GxEI, animal model methodology and the genetic correlation between the traits were used. GxEI was generally smaller for fat and milk yield than for protein yield. The lowest genetic correlations between high and low environments were estimated for protein yield, especially in Simmental (0.81) and in Brown (0.86) breed. In Holstein the correlation was higher, 0.94. The genetic correlations for fat yield were 0.95 for Brown and Simmental breed and 0.96 for Holstein. For milk yield the estimated genetic correlations were 0.88, 0.92 and 0.96 in Brown, Simmental and Holstein breed, respectively. Differences between variance components obtained in low and high quartile result in the rank of heritabilities from 0.04 to 0.12 in low and from 0.12 to 0.22 in high quartile.
PPARGC-1 gene is assumed to be a candidate gene with a major effect on fatness and meat quality. In this study, frequency of T/A substitution at position 1378 in PPARGC-1 gene in pigs was examined in ...boars of 4 different breeds. Frequency of genotypes and alleles were compared between animals with the thinnest and with the thickest backfat. Differences in genotype frequency between groups were significant in dam line of Slovenian Landrace (SL11) and sire line of Large White breed (LW66). Allele A was predominantly present in animals with thick backfat in SL11 (71.05%), LW66 (58%) and in sire line of Slovenian Landrace (67.65%). Differences in allele frequency were significant in SL11. We found a significant effect on phenotypic and breeding values for backfat in population of Large White breeds, where homozygotes TT had the thickest backfat, and heterozygotes the thinnest. In population of Slovenian Landrace breed the thickest backfat had homozygotes AA and the thinnest homozygotes TT. Similar results were obtained by analysis of gene effect on breeding values. Inconsistency could be explained by different background of allele, epistasis and intensity of selection.
Namen raziskave je bil izvrednotiti genetske korelacije med velikostjo gnezda pri mladicah in pri starih svinjah. Analizirali smo število rojenih in število živorojenih pujskov od prve do šeste ...zaporedne prasitve. Skupno je bilo vključenih 24 334 prasitev pri pasmah švedska landrace (SL) in large white (LW), liniji 12 (SL × LW) in liniji 21 (LW × SL). Z modelom živali smo ocenili visoke genetske korelacije med velikostjo gnezda pri mladicah in starih svinjah tako za število rojenih (0,92) kot za število živorojenih pujskov v gnezdu (0,92), kar nam je služilo za obravnavo velikosti gnezda pri različnih zaporednih prasitvah kot ene lastnosti. Oceni heritabilitet za velikost gnezda pri mladicah ter pri starih svinjah sta višji za število rojenih (0,14) kot za število živorojenih pujskov (0,12). Dobljeni rezultati nakazujejo primernost ponovljivostnega modela za selekcijo velikosti gnezda v proučevani populaciji.
Genetic parameters for weaning-to-oestrus interval (WOI) were estimated on 11,026 sows from pig selection farm Ptuj (Slovenia). Univariate analyses of observations of WOI across parities and ...two-trait analyses of records of primiparous (PP) and multiparous (MP) sows were performed applying Bayesian approach. WOI was analysed on original scale, transformed using a natural log transformation (lnWOI) and considered as a mixture of normal and exponential distributions (trWOI). Statistical model included genotype, season of service as year-month interaction, and parity as fixed effects, and previous lactation length and number of piglets weaned as covariates. Direct additive genetic effect and permanent environment were considered as random effects. (Co)variance components were estimated by Bayesian analyses. Gibbs chains of length between 130,000 and 180,000 were run. Univariate analysis for sows across parities resulted in heritability estimates of 0.06, 0.07, and 0.07 for WOI, lnWOI and trWOI, respectively. Permanent environment (PE) accounted for 26 % of phenotypic variation for WOI and 19 % for both lnWOI and trWOI. In bivariate analysis, heritability was 0.19 in PP and 0.06 in MP. Genetic correlation for WOI between PP and MP was 0.80. The PE proportion was 0.10 in MP sows. Based on genetic parameters, selection on improved rebreeding performance in pigs is expected to be most efficient considering WOI in primiparous and multiparous sows as different traits. Transformation of WOI increased the genetic parameters only slightly.
Urine cortisol concentration was evaluated in German Landrace barrows of two MH-genotypes (NN, Nn) housed in metabolic cages. Furthermore, cortisol in urine was evaluated as a substitute measure of ...plasma cortisol values in pigs. Three replicates were done, each including 4 animals. Altogether there were 12 animals included in the experiment. The effect of MH-genotype on urine cortisol concentration was evaluated and correlations between urine and plasma cortisol were calculated. Higher urine cortisol values in NN- in comparison to Nn-pigs indicated stronger response to stressors by stress resistant NN-genotype. The correlation between urine (12-hr urine values) and plasma (the average of 12 collections per day, taken between 8.00 a.m. and 11.00 a.m.) cortisol values was practically negligible in samples taken on the same day (r = 0.07, P = 0.71). In time-lag samples (urine taken the day after blood collection) correlation was increased (r = 0.22), but still not significant (P = 0.22). A connection between plasma and urine cortisol values was indicated, but it should be better understood before urine cortisol is used as a substitute of plasma cortisol measuring in pigs.
V raziskavo je bilo vključenih 46 960 prasitev pri svinjah pasme švedska landrace (SL) in large white (LW) ter F1 križankah teh pasem, liniji 12 (SL x LW) in liniji 21 (LW x SL). S ponovljivostnim ...modelom živali smo analizirali število rojenih in število živorojenih pujskov od prve do šeste zaporedne prasitve. Razliko med posameznimi genotipi smo obravnavali v obliki parametrov križanj. Proučevali smo maternalne komponente: aditivni maternalni vpliv, maternalni heterozis in aditivni vpliv stare matere, ki so bile obravnavane kot neodvisne spremenljivke. Prispevek aditivnega maternalnega vpliva k razliki med pasmama (SL-LW) je bil večji za število živorojenih (0,36) kot za število rojenih pujskov (0,09). Oceni maternalnega heterozisa, ki pojasnjujeta odstopanje linij od povprečja pasem, sta za število rojenih pujskov 0,69 in 0,72 za število živorojenih pujskov v gnezdu. Razlika med linijama (SL x LW-LW x SL) je zanemarljiva (0,06 za rojene in –0,03 za živorojene pujske).
Modeli z naključno regresijo MALOVRH, Špela; KOVAČ, Milena
Acta agriculturae slovenica,
11/2000, Letnik:
76, Številka:
2
Journal Article
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Proizvodnost plemenskih živali je pogosto merjena v zaporednih intervalih, kot so lastnosti mlečnosti, rasti, zauživanje krme in zunanjost. Meritve, zbrane ob različnem času ali na različnem mestu, ...so med seboj odvisne. Njihova povprečja in standardni odkloni se s časom spreminjajo in korelacije so odvisne od oddaljenosti med meritvami. Modeli z naključno regresijo (MNR), ki opisujejo proizvodne funkcije, v povezavi s kovariančnimi funkcijami, ki zajamejo časovno oz. prostorsko odvisnost komponent (ko)variance, so najprimernejši za analizo take vrste podatkov. MNR smo primerjali z modeli za laktacijske zaključke, modeli z intervali in z modeli s sistematsko regresijo po virih. Za ponazoritev smo uporabili podatke slovenske populacije črno-belih krav. MNR boljše opišejo biološko ozadje proizvodnosti živali v času in omogočajo selekcijo tako na raven kot obliko proizvodnih funkcij. Dovoljujejo gibljivejši postopek preskusa in s tem znižanje stroškov pri zbiranju podatkov. Plemenske vrednosti lahko napovemo pred koncem laktacije, kar skrajšuje generacijski interval, pogostejši izračuni pa so lahko tudi v pomoč pri vodenju reje.
Izhodišča. Namen raziskave je bil opredeliti kratkoročno in dolgoročno uspešnost programa glede na vztrajanje v njem, ITM, vrednost krvnega sladkorja, holesterola in krvnega tlaka pri udeležencih, ki ...so program zaključili. Želeli smo tudi opredeliti dejavnike, ki napovedujejo vztrajanje v programu.
Z namenom proučevanja možnosti vključitve klavnih lastnosti v napoved plemenske vrednosti pri prašičih smo ocenili komponente variance za lastnosti, ki se za ocenitev odstotka mesa v prašičjem trupu ...merijo na klavni liniji ter za lastnosti šunke. V analizo smo zajeli 2167 pitancev (1046 kastratov in 1121 svinjk) z znanim poreklom. Pitanci so bili skupinsko vhlevljeni s krmljenjem po volji v proizvodnih razmerah na farmi Nemščak. Zaklani so bili med aprilom 1999 in decembrom 2000. Komponente variance smo ocenili z enolastnostnimi modeli po metodi omejene največje zanesljivosti (REML). V sistematski del modelov smo vključili vpliv spola, genotipa in sezone (leto-mesec) kot vplive z nivoji ter maso toplih polovic ali starost ob zakolu kot linearni regresiji, v naključni del pa vpliv živali. Ocene heritabilitet so bile srednje do visoke; za maso toplih polovic (0,32), za meritev M (0,41), ki je najkrajša razdalja med prednjim koncem m. gluteus medius in zgornjim robom hrbteničnega kanala, za meritev S (0,45), ki je najtanjša debelina podkožnega maščobnega tkiva s kožo nad m. gluteus medius, za odstotek mesa (0,46), za maso mesa (0,38), za maso šunke (0,32), za maso kože s podkožno maščobo šunke (0,47), za maso mesa in kosti šunke (0,41), ter dnevni prirast mase toplih polovic (0,32) in dnevni prirast mase mesa (0,38). Poleg heritabilitet so bile velike tudi aditivne genetske variance. Za vključitev v selekcijski program bi na podlagi ocen predlagali odstotek mesa in maso kože s podkožno maščobo šunke.
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