**1. Introduction**

Beef and dairy cattle play the unique role of providing high quality protein for human consumption from forage and other concentrated feed resources. Globally the cattle sourced protein is the most common, popular, most available, acceptable and affordable by most people in terms of cost per unit weight. The intensive production of beef and milk sourced from cattle through the use of new technologies in livestock agriculture could lead to increased number of animals with greater yield in livestock products such as beef and milk [1]. The enhancing technologies could be in the form of mechanical, biological and chemical tools. The use of larger and faster implements would enable the need for lesser human power to operate and achieve larger land cultivation, leading to higher beef and milk yield. Thereafter, the application of chemical fertilizers and herbicides would increase the rate of forage cultivation and feed production. The authors [1] further outlined that animal drugs and antibiotics use would result to increased animal health, reduction in mortality accompanied by

increased beef and milk production under the lower levels of input application. These could thus result into higher profit margin due to lowered cost of production.

The growing human food needs of an expanding human population, the challenges of global climate change have resulted in the need for the development of sustainable ruminant production systems [2]. It has been projected by FAO [3] that the world population would become 9.73 billion by 2050 and 11.2 billion by 2100. Globally, most young people are expected to live in the Sub-Saharan Africa and Asia, and particularly in the rural areas where higher rate of unemployment exist. Thus, there could arise the situation whereby there would be a world population increases, there would be high rate of urbanization by the youth, with the aged people left in the rural agricultural cultivation and production areas. These could make it difficult to meet the requirement for agricultural labour force and socioeconomic structure needed by the rural community to achieve sustainable development goals [3]. A group of researchers [4], reported for beef cattle production while another group [5], reported for dairy cattle production that through the intensification of beef and dairy cattle production systems, genetic selection for either beef or dairy cattle, and the use of modern technologies such as artificial insemination and genomic selection, the beef and dairy cattle industries have more than doubled in their production over past decades. However, there had been the contrasting dramatic reduction in the total number of pure-bred cattle being raised globally either for beef or for milk. There were also observed few unfavourable responses in relation to fertility, health challenges, longevity and environmental sensitivity. Again, as earlier mentioned, large numbers of offsprings from pure-bred dairy cows do enter beef fattening systems as milk-fed veal producing beef cattle [6]. Thus, this article reviews the intensified systems of beef and dairy cattle production worldwide.
