Which of the following physiological responses occurs in pigs experiencing heat stress? (Select all that apply)

The assignment describes enlargement of skin blood vessels to increase blood flow to the surface, as well as increased respiratory rate, open-mouth breathing, panting, and reduced feed intake above the comfort zone. It specifically notes that pigs release little moisture from the skin, so heavy sweating is not identified as their primary response. **Key takeaway:** Pig heat responses include increased surface blood flow and respiratory heat loss, while appetite and production may decline.\n\n**Glossary:**\n- **Vasodilation**: Widening of blood vessels.\n- **Respiratory rate**: Number of breaths taken per unit of time.\n- **Feed intake**: Amount of feed consumed.