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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Livestock, Forage and Pasture Management Research Unit » Research » Research Project #444538

Research Project: Using Natural Sources of Tannins to Mitigate Greenhouse Gas Emissions by Cattle Grazing Winter Annual Pasture

Location: Livestock, Forage and Pasture Management Research Unit

Project Number: 3070-31630-008-006-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: May 31, 2023
End Date: May 30, 2028

Our research purpose is to advance the understanding of peanut skins as a supplement for beef cattle and a enteric methane mitigate. Research has focused on trying to find a palatable feed mix containing peanut skins for cattle grazing high-quality wheat forage. Research has studied corn plus peanut skins as supplement to potentially improve reproduction in heifers grazing vegetative wheat; we hypothesized that this effect could be attributed to the supplement's potential to reduce blood urea nitrogen, increase fecal nitrogen excretion, decrease urinary nitrogen output, and improve nitrogen balance. We are unsure what contribution to this effect could be contributed to peanut skin tannins or to the starch in corn. The potential for tannins to increase fecal nitrogen excretion and reduce blood urea nitrogen and urinary nitrogen also has potential environment benefits. Our objectives is to further investigate performance and physiological processes associated with use of peanut skin tannins as a supplement to ruminants.

Our approach will be to further assess peanut skins as part of a supplement for cattle grazing wheat pasture using a series of studies. Theses studies will include going back to our original supplement and examining the effects of no supplement, corn alone, or corn in combination with peanut skins on performance with a subset of calves used to assess blood urea nitrogen, fecal nitrogen excretion, and dry matter intake. We will expand on this by comparing our corn plus peanut skins supplement to a corn based supplement formulated with other byproducts to target similar protein, fat, and digestible energy for comparison of blood urea nitrogen and fecal nitrogen excretion. The results of these projects should provide insight into the peanut skins' affect on reducing nitrogen absorption, increasing fecal nitrogen excretion, and thus potentially having beneficial environmental consequences from excreted nitrogen. Plasma urea nitrogen will be measured using an elisa assay. Fecal nitrogen will be estimated using dosed indigestible markers. Forage intake will be predicted from NRC equations, estimated from marker based estimates of total tract digestion and fecal output, and assessment of forage disappearance during rotational grazing. Field response to recycled nitrogen will be assessed through vegetative indices calculated from multi-spectral images.