Metabolic profile according to the parity and stage of lactation of high-performance Holstein-Friesian cows

Objective The aim of the study was to determine the effect of parity and the stage of lactation on the metabolic profile of cows based on the basic chemical milk components and the blood parameters. Methods The study material consisted of the high-yielding Holstein-Friesian (HF) cows. In total, 473 cows were examined. According to the parity, cows were divided into four groups: primiparous (P), and multiparous in the second (M2), in the third (M3) and in subsequent lactations (M4). The feeding of cows was based on total mixed ration (TMR) ad libitum. Milk and blood samples were collected individually from each cow three times per standard lactation period. Results Greater exacerbation of changes in the dynamics of the blood plasma parameters examined was proved for multiparous cows. The highest value of BHBA (0.946mmol/L) was found for multiparous cows from group M3 at the beginning of lactation. However, it was the normal range, stillThe results showed AST, ALT and GGT activities in dairy cows during lactation showed significant variations taking in to account stage of lactation. The highest activity of GGT was found in the group of the oldest cows and measured from 26.36U/L at the beginning of lactation to 48.75U/L at the end of the lactation period. Conclusion The time-related changes in the concentrations of the biochemical parameters described differ markedly among lactating cows, though the housing conditions on the research dairy farm are highly standardised. This indicates that the ability to cope with metabolic stress is mainly probably affected by the individual predispositions of cows and feed nutrient supply in different stage of lactation. Especially, the feed nutrient supply (in NEL), which was the best in TMR1 in comparison TMR3.