K. Potočnik

1 University of Ljubljana, Biotechnical Faculty, Department of Animal Science, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia 2 Corresponding author, e-mail: Klemen.Potocnik@bf.uni-lj.si 3 Same address as 1, e-mail: barbara.lustrek@gmail.com 4 University of Zagreb, Faculty of Agriculture, Department of Animal Science and Technology, Svetošimunska 25, 10000 Zagreb, Croatia, e-mail: akaic@agr.hr ABSTRACT The purpose of this study was to determine the impact of genomic selection on A2A2 ß-casein genotype in Brown Swiss cattle on important dairy production traits – traits included in total merit index (TMI). A total of 190 Slovenian Brown Swiss cattle, 83 females and 107 males, with known direct genomic values (DGV) from InterGenomics project and known genotype for ß-casein were used for estimation of the genotype effect. The determined genotype frequencies in population were 2.63 % for A1A1, 35.26 % for A1A2 and 62.11 % for A2A2 genotype. For DGV data analysis a single–trait model was u...

Analysis of inbreeding and inbreeding depression was done on the data of routine breeding value estimation for milk production data on Holstein population in Slovenia. A pedigree file of 106 433 animals born from 1952 to 2005 was investigated for the occurrence of inbreeding. The maximum inbreeding was 37.5. However average inbreeding coefficients of inbred cows (1.3 %) and of all cows with test day records (0.989 %) were low. Daily milk, protein, and fat yield of first five lactation for 86 122 cows were analyzed. Inbreeding was included in the animal model as a linear covariate. The regression coefficients of milk, fat, and protein yield, multiplied with 305 days present inbreeding depression of lactation yields, were -22.17 kg, -0.601 kg and -0.387 kg respectively, for 1 % of inbreeding.

This study demonstrated the feasibility of a genomic evaluation for the dairy cattle population for which the small national training population can be complemented with foreign information from international evaluations. National test-day milk yield data records for the Slovenian Brown Swiss cattle population were analyzed. Genomic evaluation was carried out using the single-step genomic best linear unbiased prediction method (ssGBLUP), resulting in genomic estimated breeding values (GEBV). The predominantly female group of genotyped animals, representing the national training population in the single-step genomic evaluation, was further augmented with 7,024 genotypes of foreign progeny-tested sires from an international Brown Swiss InterGenomics genomic evaluation (https://interbull.org/ib/whole_cop). Additionally, the estimated breeding values for the altogether 7,246 genotyped domestic and foreign sires from the 2019 sire multiple across-country evaluation (MACE), were added to ...

The aim of this work was to study the intramuscular fatty acid profile of Mediterranean lambs using a meta-analysis. The database was created from five journal articles and one doctoral dissertation, and included lambs of the Talaverana, Comisana, Churra Tensina, Merino Branco and Pramenka breeds. All analyses were performed using Comprehensive Meta-Analysis and R statistical software. According to the overall pooled result, lambs of Mediterranean breeds included in our meta-analysis had 22.85 % of palmitic (C16:0), 14.78 % of stearic (C18:0) and 5.32 % of myristic acid (C14:0). The overall pooled result for oleic acid (C18:1) was 32.53 %, and it was 5.60 % for linoleic acid (C18:2 n-6) and 1.95 % for…

In the light of increasingly rapid climate change worldwide, and with the purpose of reduction of financial losses of dairy farmers and enabling the sustainable farming, the necessity of implementation of breeding values for heat resistance in breeding strategies, have become more and more pronounced. Estimation of breeding values requires determination of THI threshold value. Therefore, the objective of this research was to determine the THI threshold value for Holstein heifers in environmental conditions in Central Croatia. With that purpose individual test-day records of Holstein heifers with records of ambient temperature and relative humidity in the barns collected in regular milk recording from January 2006 to December 2012 were analysed. The THI threshold values for daily milk yield were determined by least square analyses of variance for each given THI value (from 65 to 76) using the PROC MIXED (SAS). The THI ≥ 65 cause significant change in Holstein heifers’ daily productio...

In the light of increasingly rapid climate change worldwide, and with the purpose of reduction of financial losses of dairy farmers and enabling the sustainable farming, the necessity of implementation of breeding values for heat resistance in breeding strategies, have become more and more pronounced. Estimation of breeding values requires determination of THI threshold value. Therefore, the objective of this research was to determine the THI threshold value for Holstein heifers in environmental conditions in Central Croatia. With that purpose individual test-day records of Holstein heifers with records of ambient temperature and relative humidity in the barns collected in regular milk recording from January 2006 to December 2012 were analysed. The THI threshold values for daily milk yield were determined by least square analyses of variance for each given THI value (from 65 to 76) using the PROC MIXED (SAS). The THI ≥ 65 cause significant change in Holstein heifers’ daily productio...

... ANALYSIS OF LONGEVITY IN SLOVENIAN HOLSTEIN CATTLE Klemen POTOČNIK 1, Vesna GANTNER 2, Jurij KRSNIK 1, Miran ŠTEPEC 1, Betka LOGAR 3, Gregor GORJANC 1 ... Similar results were obtained also by Vollema and Groen (1998) and Rogers et al. ...