The biotic factor which derives much benefit from livestock and reduces productivity is a

The biotic factor that derives much benefit from livestock and reduces productivity is a parasite. A parasite is an organism that lives on or within another organism, known as the host, and benefits at the host's expense. Livestock can be hosts to a variety of parasites, such as ticks, lice, and worms, which can cause harm to the animals and reduce productivity. Parasites can lead to weight loss, anemia, reduced milk production, and even death in severe cases. Additionally, parasites can be transmitted from livestock to humans, leading to health problems. Therefore, it is important for livestock producers to manage parasite infestations through various methods, such as deworming and sanitation, to ensure the health and productivity of their animals.