engleski

Influence of dietary clinoptilolite supplementation on milk fat to protein ratio and β-hydroxybutirate serum levels during transition period in dairy cows

The aim of the study was to establish the influence of dietary clinoptilolite (CPL) supplementation on milk fat-to-protein ratio (FPR) and serum β-hydroxybutirate (BHB) levels during transition period in dairy cows. Thirty pregnant cows for 240 days of the Holstein- Frisian breed, aged from 3 to 5 years and kept in a farm near Đurđevac, Croatia, were used in the trial. The cows were randomly assigned into two groups (either in-feed CPL treated ; CPL group or control non-treated ; CON group) comprising 15 cows each. The CPL group received 100 g of natural modified clinoptilolite preparation (Vibrosorb, Viridisfarm, Podpićan, Croatia) in the ratio for dairy cows on a daily basis. Blood samples were collected from the cows in the period from day 240 to 260 of pregnancy, after parturition (day 0), and on days 12, 26, 40 and 60 of lactation. During lactation, milk samples were taken (same days when a blood samples were taken) for milk fat and milk protein analyses. The average value of BHB was higher in the CON than in the CPL group (0.99±0.10 vs. 0.81±0.99 mmol/L). The highest concentration of BHB was obtained on days 0, 12 and 26 of lactation in the CON group (1.83±0.35, 1.55±0.35, and 1.62±0.35 mmol/L, respectively) and in the CPL group after parturition, on day 0 (1.79±0.41 mmol/L). The FPR was significantly higher in the CON group on day 0, (P<0.05) as well as on days 12 and 26 slightly higher than in the CPL group. However, on day 10 before parturition FPR was slightly higher in the CPL group then in the CON group. Such similar trends are associated with decreasing level of BHB following parturition. Hence, by determining of the BHB levels (in blood, urine or milk), the FPR could be used for an early diagnosis of subclinical ketosis. Also, the results of this study indicated that CPL applied as dietary supplement could be effective in reducing clinical signs of ketosis.

dietary clinoptilolite ; β-hydroxybutirate ; milk fat-to-protein ratio ; transition period ; dairy cows

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