Richard and Brogan Scarfe caused a "high level of suffering" to farm animals, a court hears.
A drought is officially declared in south-west Wales after heatwave causes water levels to plummet.
Lewis Haines will stand trial accused of Lily Sullivan's murder, after admitting manslaughter.
Lewis Haines, 31, was remanded in custody until his next court date in January.
Lily Sullivan's body was found on Friday morning, with a 31-year-old man charged with her murder.
Lewis Haines is due to appear before magistrates on Tuesday, Dyfed-Powys Police says.
