Interpretive Summary: Using an automated head chamber system to administer an external marker to estimate fecal output by grazing beef cattle

By Anne Zinn

Concern for the environment and the impact of livestock production on climate change is an increasingly relevant subject of interest. Scientists have estimated that 14.5% of all anthropogenic greenhouse gas emissions come from global livestock production (animals, manure, feed production, and expansion of lands into forested areas) and, of that, 39% results from enteric methane emissions. Therefore, research surrounding the reduction of greenhouse and methane emissions is extremely important and timely. A paper recently published in the Journal of Animal Science aimed to determine if titanium dioxide dosed through an automated head chamber system, GreenFeed, is an acceptable method to measure fecal output. The research team hypothesized that there would be adequate agreement in fecal output estimated using titanium dioxide as an external marker dosed between the GreenFeed and hand feeding in stanchions. If titanium dioxide can be successfully dosed by the GreenFeed baiting system to create a steady state of marker excretion, there could be several benefits, such as reduced labor, increased experimental units, and reduced grazing behavior disruption. 

Results of this study indicated that researchers can dose indigestible external markers to grazing cattle that are being monitored for respiratory gas emissions by the GreenFeed. It was concluded that delivering an external marker through the GreenFeed provides an unbiased estimate because the fecal output estimates being nearly identical between delivery methods, keeping in mind that consideration of the increased variability of the fecal output estimates is necessary for future experimental designs. The research has confirmed and highlighted the potential for dosing cattle with an external marker through a GreenFeed configured with two or more feed hoppers.

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