As we transition from spring to summer, feedlot cattle face an increase in digestive issues such as bloat and other abnormalities. However, during the warmer months of June, July, and August, another problem called fatigued cattle syndrome becomes a growing concern for producers, veterinarians, and processors.
Fatigued cattle syndrome is a metabolic disorder that affects all four limbs of the animal. It is believed to be a multifactorial problem, according to Jacob Hagenmaier, a veterinarian and director of clinical services for the Veterinary & Biomedical Research Center in Manhattan, Kansas. A similar syndrome called fatigued pig syndrome (FPS) exists in hogs, which is why the name was adopted for the condition observed in cattle. The USDA attributes predisposing factors to FPS in pigs, including the pig itself, the environment/facility, people, transport, and processing plants. These factors are likely applicable to fatigued cattle syndrome as well.
The syndrome was first reported in 2013 when cattle arriving at packing plants exhibited decreased mobility, muscle tremors, and hoof wall sloughing without any apparent cause of lameness. Some affected cattle could still be processed for human consumption, while others became non-ambulatory or "downer" animals that had to be euthanized, resulting in significant financial losses for owners.
To address the severity of the syndrome, a locomotion scoring system specific to fed cattle was developed. Known as the NAMI Mobility Scoring System, it consists of four mobility scores, ranging from normal to extremely reluctant to move. The system helps define the symptoms and signs exhibited by cattle, with a score of 4 resembling the tying-up syndrome observed in horses.
Metabolic acidosis is commonly present in cattle with mobility scores of 3 or 4. High lactate levels contribute to this disease, as cattle have limited lung capacity for efficient aerobic respiration, leading to lactic acid buildup. The increasing trend of feeding cattle to higher finish weights has raised concerns about their ability to cope with the stress and whether their musculoskeletal systems can keep up.
While some initially believed fatigued cattle syndrome was more prevalent in cattle exposed to beta-agonists, research has not substantiated this claim. Ongoing studies, including those conducted by Kansas State researchers, continue to explore the relationship between beta-agonist products and the syndrome.
To prevent fatigued cattle syndrome, the industry can focus on improving handling, feeding, and management practices throughout the cattle's time in the feedyard until they are ready for slaughter. Recommendations include ensuring a well-rounded nutritional program, using low-stress handling techniques, staging cattle near loadout areas in advance, having knowledgeable personnel handle the animals, and allowing sufficient time for animals to walk from pens to loadout. Additionally, it is advised to avoid overloading transport systems and to consider factors such as temperature, shade, and access to water during shipping.
While addressing fatigued cattle syndrome may pose challenges, implementing these practices can help minimize its occurrence, improve animal welfare, and mitigate financial losses for producers.