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The zeolites are crystalline, hydrated aluminosilicates and cations clustered to form micro aggregates with three-dimensional structures comprising multiple micro pores. The pore sizes modulate their unique catalytic properties. Among 140 types of natural zeolites, clinoptilolite (CPL) is the most widespread compound in the medical market and recently has been approved as feed additive in the EU. The CPL utilization in animal biotechnology and veterinary medicine are as detoxificating, antioxidant, hemostatic, anti- diarrheic, growth-promoting and immunostimulating agent, and in human medicine as adjuvant in immunodeficiency, oncology (after chemotherapy and radiotherapy) or reducer of radioactive elements. Findings that zeolites may improve the energy status of dairy cattle, especially in early lactation, could be interpreted that the dietary inclusion of CPL might have beneficial effects on the reproductive efficiency of dairy cattle. Recent study that long term (Day 210 of gestation until the end of the first lactation period) dietary inclusion of CPL to pregnant heifers improved energy status, resulting in a milder form of negative energy balance (NEB), and consequently increased reproductive efficiency and milk production in the first lactation. Reproductive efficiency is a key factor for profitability of the dairy herds, and is frequently affected by numerous factors such as NEB, age, milk yield, cattle breed, health status and herd management, including nutrition and type of housing. Nutritional requirements of dairy cows are rapidly increasing following parturition due to milk production and inevitably the animals entering NEB which indirectly affects ovaries function causing failure of regular ovarian activity during puerperium and consequently decrease fertility. The NEB could not be avoided by any known treatments but it is possible to decrease its duration and severity. Energy imbalance occurs due to increased milk production following parturition, peripartal stress and/or puerperal diseases. Such diseases have significant negative economic impact, during puerperium and afterwards by appearance of infertility. One of the most important puerperal diseases is mastitis which causes large economic losses particularly due to difficulties in diagnosis of its subclinical form. It is assumed that CPL might modulate metabolic, endocrine and antioxidative status in dairy cows and thus improve their health, fertility and milk production. The objectives of this study are to evaluate effects of nutritive modulation by dietary CPL on: NEB, fertility, productivity and incidence of subclinical mastitis for early recognition of oxidative stress and systemic/local inflammatory responses involved in reproductive and productive disorders in dairy cows. Altogether, these will contribute in practice to improve health and economical parameters in cattle production. |
