Abstract
Footrot is a highly contagious disease with significant economic and animal welfare impacts on the small ruminant livestock industry. Host genetics, environmental conditions, nutrition, foot shape and structure, and age contribute to small ruminants' susceptibility to footrot. Selection for footrot resistance is a promising way to classify susceptible or resistant small ruminants without subjecting them to a pathogenic challenge, to reduce disease prevalence, to improve small ruminants' health and welfare and to produce safe, high-quality food. To date, there has been little focus on footrot resistance heritability and response to selection in small ruminants. This review paper (a) explains footrot and its aetiology in small ruminants, (b) describe genetics of disease resistance and marker-assisted selection, (c) discusses footrot resistance heritability, (d) addresses phenotypic and genetic variation in footrot resistance and selection for footrot resistance, and (e) defines phenotypic and genetic assessment for footrot resistance and footrot gene-marker screening test.