Option 1 states that farming along with animal husbandry is called mixed farming. Mixed farming is a type of agricultural practice where both crop production and livestock rearing are carried out on the same piece of land. This combination of farming and animal husbandry allows for the use of resources in a more sustainable and integrated manner. Farmers practicing mixed farming can benefit from the synergies between crops and livestock, such as utilizing animal waste as fertilizer for crops and using crop residues as feed for the animals.

Option 2, mixed agriculture, is incorrect because agriculture refers to the broader term of cultivating crops, while animal husbandry specifically relates to the rearing of animals.

Option 3, dairy farming, refers to a specific type of animal husbandry that focuses on the rearing of dairy cattle for milk production, which is not inclusive of crop production.

Option 4, truck farming, refers to the practice of growing fruits and vegetables on a small scale and selling them directly to consumers, rather than through a wholesaler or retailer. This term does not encompass animal husbandry.

Therefore, the correct answer is option 1 - mixed farming.