**2. History**

Intensive animal farming is the most recent advancement in agriculture history which is also the result of scientific and technological developments. In the late nineteenth century, innovations were made in mass production. Later, in early twentieth century; vitamin discovery and their associated role in animal nutrition was the hallmark of Industrial Revolution because it allowed poultry to be raised at the domestic level [14]. Moving further, antibiotics and vaccines discovery have further lightened the livestock by reducing the number of disease-causing pathogens [15]. Chemicals used in World War II gave the idea of synthetic pesticide discovery [14]. The development of transport networks and technology enabled the distribution of agricultural products over long distances.

The era of high-put farming began in Britain in 1947, when the new Agriculture Bill provided subsidies to farmers to promote more production by introducing new technologies to reduce Britain's dependence on imported meat. According to United Nations "the intensification of livestock production" was found to ensure food security [16]. In 1966, the United States, Great Britain, and other developed countries began large-scale farming of beef and dairy cattle and domestic pigs [17]. From the heartland of America and Western Europe, factory farming became globalized in the later twentieth century and continues to expand, replacing traditional livestock

farming practices in an increasing number of countries. In 1990, intensive animal husbandry accounted for 30% of world meat production, and by 2005 this had risen to 40% [17]. Worldwide meat production in 2020 was 328 million tons which suggests that the demand for meat has reached 90% [18].
