Predicting Disease in Cattle

By Arden Wohlers DVM
Extension Veterinarian
University of Nebraska Panhandle Research and Education Center

How great would it be if we could draw a blood sample on a feeder calf and predict if he would become sick during the fattening phase of his life? We could sort calves into high risk and low risk groups. The high risk group could then be given extra attention and care to prevent many of them from getting sick. Specifically we could prevent many calves from developing respiratory disease that costs the beef industry 1 billion dollars per year. There would be a labor savings since the feedyard crews could concentrate on the 25 per cent of the group that are most likely to get sick. There could be a cost savings from not giving the entire group a prophylactic antibiotic when there is a concern that indicates there may be more sickness then usual.

We now have a method of measuring a calf’s susceptibility to disease. This is a measure of the calf’s ability to produce antioxidants and enzymes necessary to neutralize free radicals. Oxidative stress is created when excessive free radicals react with proteins, cell walls and DNA causing damage to cell structures that are critical to the immune system. During the calf’s normal metabolism body cells use oxygen and form highly reactive molecules known as free radicals. Stressful events such as weaning, severe weather and transporting cattle can elevate free radical production thereby increasing cell damage. Reducing stress will decrease free radical production. Antioxidants added to the diet will help the body remove the free radicals as well.

Animal Profiling International (a company leading the development of strategic cattle management) has introduced a performance index to assess the risk of cattle developing respiratory disease. This company measures and analyzes biomarkers in the animal’s blood that indicate their ability to alleviate oxidative stress. This knowledge allows the livestock producer to identify the animals that are least likely to overcome stress and the resulting disease consequence. The analysis can be completed within 24 hours allowing the producer to be proactive in starting measures that will either prevent disease or to be more cost effective in identifying and treating sick animals.

Information on over 7,000 animals tested thus far has lead to a correlation that has shown a high index is associated with increased pulls, lower performance, and reduced treatment response. In a study conducted at a feedlot research facility in Idaho, high risk salebarn purchased cattle were used to determine economic benefit. Over 700 head of steers and heifers were sorted based on their Animal Performance Index. Savings from reduction or elimination of antibiotic use on the cattle determined to be at low risk was over $9 per head. In the ever growing market for all-natural products these cattle could have a higher value.

Cattlemen are seeking further gains in production with modifying rations and herd management by knowing which cattle are at risk of sickness. Adding higher levels of antioxidants, such as vitamin E to the ration are being explored as an option to combat the levels of oxidative stress the animals are subjected to.

Two large studies involving salebarn cattle and ranch fresh cattle will be finalized by summer and the carcass advantages obtained by utilizing the performance index will be calculated. Locally the IRM Pen of 5 Retained Ownership Group is evaluating the index on their cattle. This is a new technology that shows promise in reducing sickness and treatment costs in cattle being raised for the beef industry. It will take further review to determine if the economic benefit of the test justifies the adoption of this technology in the beef industry.

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