The Effects of Glyphosate Based Herbicides on Chick Embryo Morphology during Development

Abstract

Glyphosate based herbicides are among of the most widely used herbicides in the world. The purpose of this study was to determine developmental toxicity of glyphosate, the active ingredient in the common herbicide Roundup, on developing chicken embryos. Few studies have examined toxic effects of glyphosate alone versus the full compound formulations of Roundup, which include adjuvants and surfactants. Adjutants and surfactants are added to aid in solubility and absorption of glyphosate, possibly by making it less water soluble or lipophilic. In this study embryos were exposed on embryonic day 6 to 2% and 1% Roundup and 1% and 2% glyphosate soulutions. Injections were made directly into the air cell of the egg. On embryonic day 18 the embryos were sacrificed for morphometric measurements including: wet embryo mass, dry embryo mass, yolk mass, liver mass, heart mass, tibiotarsus length and beak length. Internal and external pipping was documented in eggs after embryonic day 18. Embryos treated with 2% Glyphosate and 1% Roundup showed significant reductions in wet and dry embryo mass, heart mass, liver mass, tibiotarsus length and beak length. Yolk mass was also significantly smaller in the Roundup animals. Mortality was also documented up to the time of external pipping. Embryos treated with 2% and 1% Roundup showed increased rates of mortality as compared with controls and active ingredient treatments.