Utjecaj klinoptilolita dodanog u hranu na profil minerala u krvnom serumu mliječnih krava

The objectives of this study were to determine whether or not dietary clinoptilolite (CPL) has an influence on the levels of calcium (Ca), magnesium (Mg), phosphorus (P), potassium (K) and sodium (Na) in the blood serum of dairy cows during gravidity and early lactation. The study was conducted on 78 dairy cows of Holstein-Friesian breed. The cows were randomly assigned into two groups: the CPL- fed treated group (n = 38) which received 50 g of natural powdered zeolite CPL twice a day from day 180 days before to 60 days after parturition, and the control non-treated group (n = 40). Blood samples were taken on days 180, 90, 60, 30 and 10 before parturition, on the day of calving and on days 5, 12, 19, 26, 33, 40 and 60 following parturition. There were no significant differences in the Ca concentrations between the CPL-fed and the control group. However, after parturition it was noticeable that the Ca concentration was higher in the CPL-fed group, especially on day 33 (P = 0.06). The concentration of P was significantly lower (P<0.05) in the CPL-fed group on day 0 and day 5 in comparison to the control group. A significantly higher ratio of Ca:P was calculated in the CPL- fed group vs. the control group on days 0, and 12. There were no significant differences observed in Mg, K, and Na concentrations between the cows in the CPL-fed group and the control group throughout the duration of the study. The results of the study suggest that dietary CPL influenced the blood levels of Ca and P in dairy cows, and improved the serum Ca:P ratio of dairy cows during the early postpartal period. The CPL applied did not produce any clinically visible disorders in the metabolism of the tested minerals. In addition, the blood levels of all tested minerals were within physiological ranges, which indicates that CPL did not alter their homeostasis in dairy cows.Cilj je ovoga istraživanja bio ustvrditi utjecaj klinoptilolita (KPL) dodanog u hranu na razine kalcija (Ca), magnezija (Mg), fosfora (P), kalija (K) i natrija (Na) u krvnom serumu mliječnih krava tijekom gravidnosti i rane laktacije. Istraživanje je provedeno na ukupno 78 krava holštajnsko-frizijske pasmine. Krave su nasumično podijeljene u dvije skupine: krave s dodatkom KPL-a u hranu (pokusna skupina) (n = 38) koje su primale dva puta dnevno po 50 g prirodnoga praškastog zeolita KPL-a, počevši 180. dan prije porođaja do 60 dana nakon porođaja, i na kontrolnu skupinu (n = 40). Uzorci krvi uzeti su 180., 90., 60., 30. i 10. dan prije teljenja, na dan teljenja te 5., 12., 19., 26., 33., 40. i 60. dana nakon porođaja. Nisu ustanovljene znakovite razlike u koncentraciji Ca između krava pokusne i kontrolne skupine. No nakon porođaja bilo je vidljivo da je koncentracija kalcija bila viša u pokusnoj KPL skupini, posebice 33. dan (P = 0,06). Koncentracija P bila je znakovito niža (P