Bob Smith, DVM, MS, Dipl. ABVP, operates Veterinary Research and Consulting Services LLC, in Stillwater, Oklahoma. He outlined some of the trends in cattle marketing and how they affect the risk of BRD.

Smith notes that several factors influence the sale price of stocker and feeder cattle. Animal health, and the risk of morbidity in a group of cattle is one of these factors. Unfortunately, that risk is one of the less predictable factors influencing cattle value, forcing buyers rely on various indicators, rather than direct measurements. Smith outlined some of those indicators and how they contribute to risk of BRD in cattle moving through the marketing system.

Commingling or mixing of cattle

Several research projects have demonstrated that commingling or mixing of calves from different farms or ranches at the auction market to make up a truckload of cattle increased the risk of respiratory disease in the calves following feedlot entry.

Knowing this, cattle buyers prefer to purchase cattle in truckload or pen-sized lots to minimize health problems associated with commingling. In one study, a lot size of 65 steers sold for an average premium of more than $6 per hundredweight compared to the price paid for a one-head lot. Purchasing larger lots of cattle also allows buyers to complete a load more quickly and reduce the time between purchase and arrival at the feedlot, further reducing the risk of disease. Cow-calf producers, he says, in many cases could improve their ability to sell larger lots of uniform cattle through genetic selection and by managing for a shorter calving season.

Weaning practices and BRD

A recent trial compared calves either simultaneously weaned and shipped to a research feedlot (Wean), weaned and held on the ranch for 45 days (Wean45) or weaned 45 days and vaccinated twice with a modified-live viral vaccine and administered one dose of Mannheimia haemolytica toxoid before shipment to the research feedlot (WeanVac45). Steers purchased from multiple auction markets served as controls. 

Total morbidity was 41.9 percent for the market calves and 35.1 percent for the Wean group, compared with 5.9% for the Wean45 calves and 9.5 percent for the WeanVac45 group. Percentage of calves treated twice was 5 to 10 fold greater for calves in the Wean group compared to those in the Wean45 and WeanVac45 groups. Health costs were highest for the Market and Wean groups, suggesting calves held on the ranch for 45 days or more should have a higher value.

That holds true in the market. Based on several years of video-auction sales data, a Colorado State University study reported price premiums of $2.47 $7.91 per hundredweight 1995 to 2005 for calves that were weaned 45 days and had been vaccinated against BRD compared to similar calves that were not in a certified health program, were not weaned before shipment and had not been vaccinated against BRD.

Cattle disposition and BRD

Researchers at IowaStateUniversity used a Disposition Scoring System to compare health and performance among docile, restless, and aggressive cattle. During the entire feeding period, average daily gain was greatest in calves classified as docile, followed by the restless group and the aggressive group. Morbidity rate was highest in docile cattle, but did not differ between the restless and aggressive cattle. Mortality rates were 1.09, 1.02, and 1.91 percent, respectively, for docile, restless, and aggressive cattle. Economic return was $62.19 lower for aggressive cattle than for docile cattle in this study. Much of this difference was attributed to increased death loss, increased ADG, and improved carcass quality grade. 

Market Value Differences between Healthy and Sick Cattle

IowaStateUniversity researchers studied the effects of BRD on economically important traits in 5,976 feedlot cattle. Incidence of BRD during the entire feeding period was 8.17 percent and total mortality was 1.43 percent with 49 percent of deaths due to BRD. This resulted in a decrease of $23.23, $30.15, and $54.01 in cattle treated once, twice, or three times or more, respectively, when compared to cattle not requiring treatment.