Interpretive Summary: Effects of bismuth subsalicylate and encapsulated calcium-ammonium nitrate on feedlot beef cattle production

By Anne Zinn

Sulfur is an important element for the ruminant animal due to its role in bacterial growth and metabolism, but high concentrations of dietary sulfur can be related to reductions in growth performance and the incidence of polioencephalomalacia. Recently, bismuth subsalicylate has been used in humans as a hydrogen sulfide mitigator to alleviate gastrointestinal disorders and nitrate has been used in ruminants as a potential compound to mitigate enteric methane, but the combination of bismuth subsalicylate and nitrate to alleviate negative effects caused by sulfur and hydrogen sulfide has not been extensively investigated.

Therefore, a paper recently published in the Journal of Animal Science hypothesized that, by adding encapsulated calcium-ammonium nitrate and bismuth subsalicylate to the diet of beef cattle, any negative effects observed when cattle are consuming a diet with greater ruminal available sulfur would be reduced, which would in turn improve growth performance, apparent total tract digestibility of nutrients, liver mineral absorption, and carcass quality. Two experiments were then conducted to determine the effects of calcium ammonium nitrate and bismuth subsalicylate, on in vitro ruminal fermentation and growth performance, apparent total tract digestibility of nutrients, liver mineral concentration, and carcass quality of feedlot beef steers.

Overall, the results observed in the present study indicate that bismuth subsalicylate does not have negative effects on feedlot steer performance and may be fed to cattle as a ruminal hydrogen sulfide mitigator. In addition, it appears to bind to sulfur as expected. However, results demonstrate that calcium-ammonium nitrate may hinder performance of steers fed finishing diets. The magnitude of the effect and the exact mechanisms of this compound within the animal are still unclear and require further research.

The full paper can be found on the Journal of Animal Science webpage.