。
She strongly condemned acts of cruelty toward animals.
Literal
She [topic-は] animals [toward-に対する] cruelty-acts [object-を] strongly condemned.
に対する is the pre-nominal form of に対して, modifying the following noun 虐待行為. The vocabulary is elevated: 虐待行為 (acts of cruelty/abuse) and 非難する (to condemn/censure) belong to formal or journalistic register. 強く (strongly) as an adverb intensifies the condemnation. This reads like a news report or essay rather than casual speech.