1 INTRODUCTION
Livestock is very important to the poor smallholder farmers, especially those in the rural areas of the sub-Saharan Africa because it generates income, serves as source of wealth, provides food and nutrition, and increase social status of the farmers (Randolph et al., 2007; Herrero et al., 2013; Oosting et al., 2014). These indicate that it can be linked to some of the United Nations Sustainable Development Goals (UN, 2015). Livestock production is, therefore, very important to poverty reduction in low-and-middle income countries (LMICs) (Pradere, 2014). Productivity of food animals in smallholder farms is often met with health challenges that invariably require the use of antimicrobials for management (Kruse et al., 2019).
Beef production is the third largest meat industry globally, with annual meat output of about 65 million tonnes (FAO, 2015). The global meat production was projected to increase from 218 to 376 million tonnes between 1999 and 2030, respectively (FAO, 2018). Beef production is complex and involves multiple stages that include calving, growing, slaughtering, and processing under intensive management with maximum use of pasture, forages, and protein and mineral supplements (Peel 2003; Cameron & McAllister, 2016). Intensification of beef cattle production facilitates antimicrobial usage (AMU) for the unavoidable infections treatment, prophylaxis, metaphylaxis, and growth promotion (Cameron & McAllister, 2016). From the general farm animal welfare perspective, AMU improves the general animal health and farm environment (Hao et al., 2014). However, confined animal feeding operations also promotes development and dissemination of antimicrobial resistant pathogens and associated antimicrobial resistance genes, especially in the environment (Agga et al., 2016).
Increased global animal protein demand and animal production intensification have led to increase in AMU on food animals and consequent antimicrobial resistance (AMR) occurrence, a worldwide health threat. Global AMU on food animals was estimated to be 63,151 tonnes in 2010 and projected to increase to 105,596 tonnes by 2030 (Van Boeckel et al., 2015), because it is expected that the majority of food animals will be herd via intensive farming by 2030. Five countries: Myanmar, Indonesia, Nigeria, Peru, and Vietnam are expected to have highest percentage increases in AMU in food animals of 205%, 202%, 163%, 160%, and 157%, respectively by 2030 (Van Boeckel et al., 2015). Globally, it was estimated that 45 mg of antimicrobials are consumed from each kilogram of harvested beef and this was projected to increase by 67% between 2010 and 2030 in the LMICs, due to increased demand for animal protein (Van Boeckel et al., 2015). Worldwide, 73% of antimicrobials purchased are used in food animals, which have led to high resistance development in livestock, with highest resistance seen against tetracycline, sulfonamide and penicillin (Van Boeckel et al., 2019).
Globally, AMU in food animals has been associated with AMR development, a situation that has led to decrease in antimicrobials effectiveness (Holmes et al., 2015). AMR has emerged as a major silent global public health pande­mic, already causing 700,000 deaths annually and could lead to as many as ten million deaths annually by 2050, with most of these deaths occurring in developing countries (O’Neill, 2014). If uncontrolled, its economic impact could cost more than US$ 1 trillion annually after 2030 (World Bank, 2017). AMR also threatens achievement of United Nations Sustainable Development Goals 2030 and African Union Agenda 2063 (The Africa We Want) Goal 3 of good health and food security. As consumption of animal protein is forecast to increase markedly over coming years in LMICs, identification of practice gaps on AMU and resistance mitigation are imperative and can only be achieved through surveillance and research.
The study objectives were: to assess farmers’ practices regarding AMU in beef cattle farms, explore risk pathways for AMR dissemination from farms, establish risk status of AMU in beef cattle production systems, and determine presence of antimicrobials residues. Our Null hypothesis was that socio-economic factors cannot drive antimicrobial misuse and resistance emergence in smallholder beef cattle production systems in Nigeria. Outcomes of the research are expected to provide background information for policy makers and feed back to beef cattle farmers through extension service delivery in developing countries.