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1

Genetic evaluation of litter size traits in Pannon Large rabbits

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Nguyen N. T., Farkas J., Szendro Z., Nagy I.
Animal Science Papers and Reports
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2017
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tom 35
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nr 2
Genetic parameters and genetic trends for the number of kits born alive (NBA), number of kits born dead (NBD) and the total number of born kits were estimated in Pannon Large rabbits. Using the REML method 12 single trait models were examined. Heritability estimates were low for all traits and ranged between 0.07-0.08 (with standard errors 0.018-0.021) for NBA (5830 records), 0.01-0.02 (0.009-0.009) for NBD (6278 records) and 0.04-0.05 (0.015-0.018) for TNB (6278 records) from 1469 does. The ratios of the permanent environmental and the phenotypic variances exceeded of the heritability estimates and ranged between 0.11-0.16(0.016-0.018) for NBA, 0.06-0.07 (0.014-0.015) for NBD and 0.11-0.17 (0.014-0.017) for TNB. When characterizing the goodness of models bias values were practically zero for all traits and models. After identifying the best fitted model (containing parity, age of the doe and year-month of kindling effects) it was extended with dominance effects. As a result, heritability estimates decreased to 0.06 (0.028) for NBA, 0.02 (0.012) for NBD and 0.02 (0.022) for TNB. The relative importance of the permanent environmental effects also decreased to 0.09 (0.031) for NBA, 0.05 (0.024) for NBD and 0.07 (0.028) for TNB. Ratios of the dominance effects exceeded those of the heritability estimates and amounted to 0.27 (0.024) for NBA, 0.05 (0.013) for NBD and 0.38 (0.025) for TNB. When compared to the additive model, the model including dominance showed some confounding with additive genetic and with permanent environmental effects and reduced calculated genetics trends (0.035 vs 0.03, -0.0017 vs -0.003 and 0.016 vs 0.01 for NBA, NBD and TNB, respectively). Spearman rank correlation coefficients between breeding values of the additive and dominance models were high for all traits (0.96-0.98). When dominance effects were included some re-ranking was observed among the top ranked animals for every trait.
2

Selection for reproduction traits in Hungarian pig breeding in a two-way cross

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Nagyne-Kiszlinger H., Farkas J., Kover G., Nagy I.
Animal Science Papers and Reports
|
2013
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tom 31
|
nr 4
The authors analysed reproduction traits in the Hungarian Large White (HLW) and Hungarian Landrace (HL) breeds and their reciprocal crosses (F1) based on the data collected within a field test between 2001 and 2010. The traits were number of piglets born alive (NBA), gestation length (GL),farrowing interval (FI) and age at first insemination (AFI). Genetic parameters were estimated separately for purebreds and crossbreds by the REML method applying two-trait repeatability models for NBA, GL, FI, and two-trait single measurement model for AFI. Records of purebred and crossbred pigs were considered separate traits. The numbers of sows for NBA and GL were 56743-167865, for FI 38541-112059, and for AFI 16083-46143. Total number of animals in the pedigree amounted to 126340. AFI was of moderate heritability with large difference between purebreds and crossbreds: 0.28 for HLW, 0.26 for HL vs. 0.40 for the HLW/HLWxHL, and 0.41 for the HL/HLWxHL crosses. Heritability estimates for GL, both in purebreds and crossbreds were moderate:0.30 for HLW, 0.22 for HL, 0.25 for the HLW/HLWxHL cross, and 0.25 for the HL/HLWxHL cross.Heritability coefficients of NBA were low at 0.09, 0.06, 0.07, 0.06, and of FI at 0.06 for all HWL, HL,and their crosses, respectively. Magnitudes of the permanent environment effects ranged between 0.04-0.07 for GL and NBA and were null for FI. Genetic correlation estimates between purebred and crossbred performances were 0.28 and 0.39 for AFI, 0.96 and 0.82 for GL, 0.82 and 0.93 for NBA,as well as 0.65 and 0.33 for FI. Selection of purebred pigs for AFI and FI crossbred performances can be based on the crossbred breeding value whereas selection for NBA and GL can use either breeding value.
3

The optimization of hydraulic protection of groundwater

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Derco J., Kralik M., Bodik I., Farkas J.
Polish Journal of Environmental Studies
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1992
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tom 01
|
nr 2
A general algorithm of hydraulic protection of groundwater (HPGW) control based on the checking of the maximal closed groundwater contour is proposed. A model describing only flow of groundwater (not spreading of contaminants) is used and therefore short computational time is sufficient to simulate various operational regimes of HPGW. Groundwater flow is described by a twodimensional two-parameters model with 'real time' generation of boundary conditions. Operation of HPGW is determined on the prediction of HPGW behaviour for 2-3 weeks forward. Results obtained using the developed algorithm are illustrated on a real HPGW operating at the 'Žitný Ostrov' in Slovakia. The usage of the proposed algorithm has made it possible to shorten total groundwater pumping to two thirds of the original value.
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