hrvatski

Modulating effects of dietary clinoptilolite (CPL) on progesterone (P4) and insulin-like growth factor 1 (IGF-1) blood concentrations in Holstein-Friesian cows during pregnancy and early lactation

Objectives: To study the effects of dietary zeolite CPL on P4 and IGF-1 blood concentrations in Holstein Friesian (HF) cows during pregnancy and early lactation. Methods: Twenty HF-cows, aged 3–5 years and kept on a commercial farm near Đurđevac, Croatia were used in the study. They were assigned into two groups, each of 10 cows. The cows from the treatment group received 100 g/day of natural CPL modified by vibroactivation and micronization (Vibrasorb, Viridisfarm, Podpićan, Croatia). Blood samples were taken on days 90, 180, 210 and 240 of pregnancy, on day 10 before and day 0 after parturition, and on days 5, 12, 19, 26, 40 and 60 of lactation. Serum concentrations of P4 and IGF-1 were determined using ELISA. The obtained data were statistically analysed using the ANOVA method with repeated measurements. Differences were considered significant at p < 0.05. Results: The average values of P4 (6.25 ± 0.73 ng/ml vs. 6.00 ± 0.58 ng/ml) and IGF-1levels (425.20 ± 59.36 ng/ml vs. 397.21 ± 41.23 ng/ml) were higher in the CPL-fed than in the control cows. During pregnancy, the highest level of P4 was recorded in the treatment group on day 90 (11.84 ± 1.78 ng/ml) and in the control group on day 240 (11.25 ± 1.69 ng/ml). In CPL-fed cows ovarian cyclity resumed on day 33 postpartum (PP), when the IGF-1 level was highest during the PP period, which was also higher (p < 0.05) than in the control cows (729.36 ± 190.39 ng/ml vs. 443.44 ± 141.91 ng/ml). Also, a consecutive increase of P4 levels was recorded from days 40 to 60 PP (5.84 ± 1.88 ng/ml and 7.87 ± 2.18 ng/ml). Conclusions: A dietary CPL preparation exhibited modulating effects on the endocrine status of dairy cows by increasing their P4 and IGF-1 serum levels during the PP period, which may influence their reproductive efficiency.

dietary zeolite ; IGF-I, progesterone, endocrine status, cow

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