“Sentience has broader and narrower senses. In a broad sense, it refers to any capacity for conscious experience. […] In a narrower sense, it refers to the capacity to have valenced experiences: experiences that feel bad or feel good to the subject, such as experiences of pain and pleasure”.

Taken from academic.oup.com/book/57949/chapter/475703402

Also, here is an article about the Cambridge Declaration on Consciousness that strongly supports the claim that sentience is a trait shared by most, if not all, of the animal kingdom.

animal-ethics.org/10th-anniversary-of-the-cambrid…