You might hear horse people talk about a "dummy" foal as a less than desirable breeding outcome.
Dummy foals act very oddly immediately after or a few hours after birth. They often have difficulty suckling and seizures. They seem disoriented and irritable. Sometimes these foals don't survive (in the past they seldom did, and treatment may involve IV feeding and oxygen).
If treated, they eventually return to normal. The technical term is "neonatal maladjustment syndrome."