By Emily Fread
Lameness is one of the top three diseases that affect dairy herds, along with mastitis and infertility (Robcis et al., 2023). Lameness is a costly disease, with the highest associated cost being reduced milk production; it has been estimated that clinical lameness causes a loss of close to 800 pounds or 5.5 pounds per day (Warnick et al., 2001) of milk on average (Green et al., 2002). Most lameness in dairy cattle is caused by foot disorders. Noninfectious foot disorders include sole ulcers and white-line disease. Infectious foot disorders include interdigital phlegmon, interdigital dermatitis, and digital dermatitis (Robscis et al., 2023). Digital dermatitis, also known as hairy heel warts, is the most common type and can typically be controlled with footbaths. Risk factors of digital dermatitis include the cleanliness of housing, poor biosecurity, and parity. Digital dermatitis can be spread when barns are not scraped regularly, and cows are left standing in manure. This disease can also be spread when new animals enter the herd. First-lactation animals are more likely to get digital dermatitis because their immune system is suppressed due to the stress of their first lactation. All cows are more likely to become lame after calving, as immune suppression also occurs during this period. Interestingly, Holsteins are the most susceptible breed to digital dermatitis (Palmer and O’Connell, 2015).
To calculate the cost of a disease, expenditures and losses must be considered. Expenditures are the cost of treatment and prevention, and losses are the indirect costs, such as reduced milk production or reproduction (Dolecheck and Bewley, 2018). Dolecheck and Bewley (2018) summarized many studies estimating the cost of lameness and found that lameness can cost between $76 and $533 per case. A recent study published in the April 2023 edition of the Journal of Dairy Science (Robscis et al., 2023) investigated the economic impacts of lameness in dairy herds. The model used in this study considered reproductive status, milk production, parity, stage of lactation, and interaction with other diseases. This model also considered whether the cow was newly or chronically lame. When considering how much lameness costs a farmer, Robscis et al. (2023) included a loss in milk production, changes in reproduction, and treatment costs. This study suggested that it costs an average of $336.91 per case of lameness. Digital dermatitis was the largest cause of lameness and cost almost $100 more than other causes of lameness. For each additional week that a cow remained lame, it cost the farmer $13.26 more per week.