Comparison of production traits of simmental cows according to bull origin

Cilj preučevanja je primerjava proizvodnih lastnosti krav lisaste pasme (LS) in križank z lisasto pasmo (LSX) glede na izvor očeta. V proučevanje smo vključili 100 krav (49 krav LS in 51 LSX), ki so prvič telile od leta 1994 do vključno 2014 na eni kmetiji, kjer so bile v enaki oskrbi z enakimi pogoji reje. Preučevali smo 7 lastnosti, ki se nanašajo na količino in kakovost mleka, 11 funkcionalnih lastnosti in 9 plemenskih vrednosti (PV). Najmlajše so telile krave LSX, ki so bile potomke tujih očetov. Dosegle so največ laktacij in s tem najvišjo starost ob izločitvi ter najkrajšo dobo med telitvama. Statistično značilne razlike (p ≤ 0,05) smo ugotovili pri povprečni prirejeni količini mleka in beljakovin v standardni laktaciji, kjer so bile boljše krave LS, potomke slovenskih očetov. Pri primerjavi količine mleka pri posamezni laktaciji smo ugotovili, da so krave LSX, potomke tujih očetov, v vseh laktacijah namolzle več mleka. Največ so namolzle v peti laktaciji, kjer je bila razlika tudi statistično značilna (p ≤ 0,05). Pri primerjavi plemenskih vrednosti smo ugotovili, da so imele potomke in matere potomk LS pasme slovenskih očetov boljše plemenske vrednosti kot potomke tujih očetov. The aim of the study was to compare the dairy cattle production traits of the Simmental breed (LS) and cross breeds with Simmental breed (LSX) in relation to the sire origin. In the study we included 100 cows (49 cows LS and 51 LSX), which have been calving since 1994, and further on until 2014 on a farm, where they have the same husbandry conditions. We investigated seven traits, which are related to quantity and quality of milk, 11 functional traits and 9 breeding values (PV). The youngest have calved LSX cows, who were descendants from foreign sires. They reached the most parities and thus the highest age at culling and the shortest calving interval. Statistically significant differences (p ≤ 0.05) were found in average milk yield and milk protein, which were better for LS descendants of Slovenian sires. When compared to the milk yield in each lactation, we found that LSX cows, which were descendants of foreign sires, had a higher milk yield in all lactations. The highest milk yield was in the fifth lactation, where the difference was statistically significant (p ≤ 0.05). When comparing breeding values of Simmental cows, we found better breeding values in mothers and their offspring in Slovenian sires when compared to foreign sires.