RESUMEN
The uniqueness of Zn is that, it is the second most abundant trace element in the animal body but can't be stored in the body, thus regular dietary intake is required. Zinc oxide (ZnO) nanoparticles (NP) particles are being extensively used in paints, skin lotions pigments, food, electronics appliances, biological and pharmaceutical applications and many more. Zinc oxide nanoparticles are the specially prepared mineral salt having particle size of 1 to 100 nm. It promotes growth can act as antibacterial agent, modulates the immunity and reproduction of the animals. Both in lower and higher doses of specifications it has exhibited a variety of effects on animal performances. Apart from being highly bio-available, reports have already pointed out the growth promoting, antibacterial, immuno-modulatory and many more effects of nano zinc (nZn). These can be used at lower doses and can provide better result than the conventional Zn sources and indirectly prevents environmental contamination also. The toxicological studies provide mixed results in animal models. Studies been undertaken in diversified animal species and encouraging effects have been reported with nZn supplementation. However, there is a need to optimize the dose and duration of ZnO NP supplementation for human and livestock, depending on its biological effects. Actual bioavailability of ZnO NP in livestock is still to be worked out. In this review we have attempted to summarize, conclude the beneficial effects of nZnO and its possible usage as mineral supplement to different categories of human and livestock.