Objective of the research was to investigate the level, structure and
variability of realized differences between average values of body condition
scores in high-yielding cows during most critical phases of production cycle.
Realized differences were used as criterion for assessment of changes
occuring in the cows? energy status through the level of increase or decrease
of body condition. Realized average values of body condition scores, for
individual and all body regions, within all studied phases of production
cycle, deviated statistically very significantly (p?0,01) from target values.
Differences between average values of body condition scores according to
phases of production cycle, for individual and all body regions, were
statistically very significant (p?0,01). Optimum body condition in dry period
was realized by 48,76% cows, at calving 53,61%, in the lactation peak 24,41%
and in mid lactation 21,12%. Average value of body condition scores at
calving was higher by 0,18 (-0,01 to 0,72) units compared to beginning of dry
period, whereas at the lactation peak it was by -1,26 (-2,75 to - 0,41) units
lower compared to calving, and in mid lactation compared to lactation peak it
was higher by 0,18 (-0,94 to 0,85) units. Within the distribution of achieved
differences in body condition scores in the time from the beginning of dry
period to calving in 346 cows or 96,11% of total number of animals (n=360)
increase of body condition score was realized ranging from ? 0,25 units.
Distribution of differences in body condition scores between calving and
lactation peak showed that 243 cows or 71,48% of total 340 cows realized loss
of body condition score of >1,00 units. Within distribution of differences in
body condition scores between the lactation peak and mid lactation, 261 cows
or 81,06% of total number of scored animals (n=322) increased the body
condition score in value of ? 0,25 units. Study showed that, except in the
dry period, changes of the body condition during other phases of production
cycle weren?t within the limits of optimum values. Realized results clearly
showed the possibility of incidence of various production disorders, health
issues and reproduction problems. Consequences are reflected also on
longevity, life production and genetic progress. Realzied differences in
average values of body condition scoreswere important basis for anticipation
of potential problems. In that regard, there are significant reserves in
improvement of efficiency of management of body energy reserves in high
yielding cows.