Interpretive Summary: Effects of protein supplementation to steers consuming low-quality forages on greenhouse gas emissions

By Anne Zinn

The vast majority of beef industry emissions are from forage-based cow-calf or stocker segments, and they present a significant opportunity to reduce methane. Providing supplements that enhance the efficiency of feed utilization can potentially reduce methane emissions from ruminants; protein supplementation has been widely used to increase intake and digestion of low-quality forages, but there is little information about its impact on methane emissions. Therefore, a study recently published in the Journal of Animal Science aimed to identify the effects of protein supplementation of either cottonseed meal or dried distillers grains with solubles on greenhouse gas emissions and energy loss of steers fed low-quality forage. The research team hypothesized that supplementing beef cattle diets based on low-quality forage with additional protein would increase energy intake and decrease methane produced per unit of gross energy intake.

Overall, the present study demonstrated that the common practice of supplementing protein to cattle consuming low-quality forage decreases greenhouse gas emissions per unit of gross energy intake and increases dry matter, organic matter, and neutral detergent fiber intake as expected. It can be concluded that this practice would also be expected to affect ruminants’ carbon footprint positively and should be investigated further. e. Boadi and Wittenburg (2002) measured methane from cows grazing timothy pastures at four stages of maturity and reported that methane emissions per unit of digestible organic matter (OM) consumed were greatest for the low-quality diets.

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