26. Potential of Southern Pine Silvopasture to Mitigate Enteric Methane Emission from and Enhance Performance of Hair Sheep

Abstract Silvopasture is an integrated grazing system comprising trees, forage, and livestock in a single unit. Trees in silvopasture provide sheds, especially during summer when the ambient temperature is too high, which might be beneficial for animals grazing there in terms of performance and reduced enteric methane (CH4) emission; one of the major greenhouse gases, however, limited research has been done on this phenomenon. This objective of this research to assess the potential of southern pine silvopasture to mitigate enteric CH4 emission from and enhance performance of hair sheep. Nineteen Katahdin ewes were stocked rotationally in silvopasture (Silvo, n = 9) and open pasture (Open, n = 10) plots. Forage samples were collected before stocking animals to respective plots and analyzed for biomass and quality (crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF); total digestible nutrients (TDN) was calculated from NDF. Performance parameters (body weight (BW), body condition score (BCS), FAMACHA, and egg per gram (EPG, McMaster method)), and enteric CH4 emission (using GreenFeed) were collected fortnightly for 70 days. Overall, Silvo had 24% higher (p < 0.0001) CP, 7.5% lower (p < 0.0001) NDF, 3.5% lower (p < 0.0.05) ADF, 5.6% higher (p < 0.0001) TDN, and 22.5% lower (p < 0.0001) biomass than Open. Ewes grazing SP had 5.7% lower (p < 0.05) BW, 12.5% lower (p < 0.05) FAMACHA, and 22.6% lower (p < 0.0001) CH4 emissions than those grazing Open. However, no difference was found in BCS and EPG. Silvopasture had better forage quality, ewes grazing Silvopasture had lower enteric CH4 emissions, however, no definite conclusion could be made on performance.