Relationships between milk urea and production and fertility traits in Holstein dairy herds in the Czech Republic

Abstract

ABSTRACT:The objective of this study was to determine how the concentration of milk urea (MU) and FPCM production affect reproduction in selected Holstein dairy herds in the Czech Republic. A retrospective, observational study comprising analyses of individual cow records from monthly dairy herd improvement (DHI) milk tests including milk urea (MU) concentration was conducted in six commercial Holstein dairy herds in cows that were bred from July 2000 to August 2003. A total of 1 333 cows with available breeding date, pregnancy status, and calving to first service interval from 31 to 150 days were selected. The data were evaluated using the mixed linear model and logistic analyses. The effect of MU concentration on the probability of conception at first service was not significant (P = 0.11). The results indicated a nonlinear relationship between MU concentration and the probability of conception. A significant effect of the length of calving to first service interval (P < 0.05) and FPCM (P < 0.05) was determined. The cows with the calving to first service interval longer than 2 months had higher probability of conception (10% higher). In the group with the highest FPCM a markedly lower level of successful pregnancy was determined (38.99%), which significantly differed from the group with average FPCM production (48.53%). The probability of conception at first service in the group with the lowest FPCM is at an average level (43.55%).

The analysis of relationships between chemical composition, physical, technological and health indicators and freezing point in raw cow milk

“…The MFP data were represented by box graphs showing milk urea and protein combination classes as the diagnostic indicator of cow nutrition in terms of their nitrogen matter and energy maintenance (overloading or malnutrition, Table 4). It means N/E nutrition balance (Kirchgessner et al, 1985(Kirchgessner et al, , 1986Bíro et al, 1992;Hanuš et al, 1993;Homola and Vencl, 1993;Jílek et al, 2006;Řehák et al, 2009). The nutrition class impact on the MFP was tested by Student's test.…”

Effect of weaning calves from mother at different ages on their growth and milk yield of mothers

“…Proper rearing conditions of a healthy and viable calf in this period are another prerequisite for making the best use of its genetic potential for dairy cows (Arave et al, 1985;Frelich et al, 2008;Řehák et al, 2009). Weaning is an important intervention in the life of calf.…”

Simple, selective, and sensitive measurement of urea in body fluids of mammals by reversed-phase ultra-fast liquid chromatography

“…On the other hand, in comparison to our ultra-fast chromatographic method (UFLC-DAD) and our previous HPLC-DAD method, the Ureakvant procedure or infrared methods (especially with Fourier's transformations) are more effective routine methods for determination of urea in large number of samples of biological origin (e.g. milk samples) (Jílek et al, 2006;Hanuš et al, 2008;Hering et al, 2008;Řehák et al, 2009). …”

“…Urea is the main and final catabolite of nitrogen compounds in humans and animals; its level often provides information on the nutritional status of monogastric and ruminal animals (Ferguson, 2000;Francis et al, 2002;Jílek et al, 2006;Sejrsen at al., 2006;Zhai et al, 2006;Řehák et al, 2009). On the other hand, creatinine, formed from phosphocreatine and creatine, is a marker of the amino acid pool and its generation reflects the slow turnover of muscle protein.…”