Dear Usman

Nanoparticles (NPs) have promising applications in medicine. Immune system is an important protective system to defend organisms from non-self matters. NPs interact with the immune system and modulate its function, leading to immunosuppression or immunostimulation. These modulating effects may bring benefits or danger. Compositions, sizes, and surface chemistry, and so forth, affect these immunomodulations. Here we give an overview of the relationship between the physicochemical properties of NPs, which are candidates to be applied in medicine, and their immunomodulation properties.

I will recommend you to read these articles;

Immunomodulation of Nanoparticles in Nanomedicine Applications

https://www.hindawi.com/journals/bmri/2014/426028/

Selenium Nanoparticles for Stress-Resilient Fish and Livestock

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4580674/

already have a glance on these articles. Any one who work on animals, birds or others similar living organisms, needs their help. 

it depend on kind of metal used in nano form, size of nano-metals, duration

and dosages