# Evaluation of the Accumulation, Distribution, and Excretion of Different Silver Species in Tissues and Feces from Chickens and Pigs Fed with Silver-Based Nanomaterial Supplemented Feeds

## TL;DR

This study examines how silver from nanomaterials in animal feed accumulates in pig and chicken tissues and is excreted.

## Contribution

The study provides new insights into the speciation and distribution of silver in animal tissues and feces after ingestion.

## Key findings

- Silver accumulates in liver and kidney but not in muscle tissue.
- Most ingested silver is excreted through feces.
- Silver in pig liver is primarily in ionic form, while feces contain both ionic silver and nanoparticles.

## Abstract

On the basis of two
in vivo experiments involving pigs and chickens,
where animals were fed with feeds supplemented with a silver–kaolin
nanomaterial as a growth promoter, the fate of the ingested silver,
its accumulation in different tissues and excretion, and its occurrence
as ionic or particulate forms has been studied. Inductively coupled
plasma mass spectrometry (ICP-MS) in conventional mode was used for
the quantitative determination of total silver in the different tissues
and feces. Results showed that silver accumulated in liver (0.15–5
mg kg–1) and kidney (0.4 mg kg–1) but not in muscle, while the major part of silver was eliminated
through the feces (75–1026 mg kg–1). Laser
ablation coupled to ICP-MS (LA-ICP-MS) in a conventional mode revealed
a preferential accumulation of silver in the outer layer of the liver
lobules in pigs. LA-ICP-MS in single particle mode (LA-SP-ICP-MS)
was applied to the analysis of tissues and feces to obtain speciation
information about the presence of ionic and particulate silver in
the samples. Silver found in the pig liver was present in ionic form,
confirming that silver was absorbed in the intestine in this form.
The analysis of pig feces confirmed the presence of both ionic silver
and particles containing silver with average masses of 520 ag (equivalent
to solid spherical silver nanoparticles of 50 nm diameter).