English to Spanish Science Livestock / Animal Husbandry

I'd like to know if there's any word in Spanish for "spotting" in the following context or the English word is used in Spanish texts as well.

"Fly spotting (fly faeces and vomit) on eggs can lead to their rejection or downgrading."

The sentence comes from an article about fly contamination in livestock production by flies (particularly in free-range layer house systems).

Thank you very much for your help.