Analýza vztahu mezi mléčnými složkami a reprodukcí u krav prvotelek českého strakatého skotu

Abstract

The aim of our study was to evaluate the relationship between reproduction and milk traits in cows of the Czech Fleckvieh. In the period of 90–180 days after calving milk of each dairy cow was analysed for constituent milk components and milk features (40 analyses in total for each sample). The database contained data concerning to the origin and reproduction traits (service period, services per conception and interval between calving and first insemination) for every single cow.When the calculated correlations were evaluated the milk yield reached significant (* p < 0.05) to very significant (**p < 0.01) negative correlation to content of some milk components: fat (−0.253**); rough protein (−0.256**); casein (−0.197**); pure protein (−0.247**); and also to content of some macroelements as: phosphorus (−0.245**); sodium (−0.261**); magnesium (−0.151*).Relation of milk yield (in kg) and reproduction traits (number of inseminations and length of service period) shows non–significant positive correlations. With increasing of milk yield, there are a higher number of services per conception and longer service period. It confirms a general tendency of deterioration of reproduction with an increasing milk yield.We have found out that when the concentration of urea, acetone, number of somatic cells and percentage of fat in milk of Czech Fleckvieh cows was increased, reproduction traits worsened (number of inseminations, length of service period). The differences were not statistically significant. This ne­ga­ti­ve relation was not proven to an interval (number of days between calving and the first insemination), where a company management may have a significant influence.