In vitroscreening of temperate climate forages from a variety of woody plants for their potential to mitigate ruminal methane and ammonia formation

Abstract

AbstractFeeding phenol-containing plants to ruminants has the potential to mitigate both methane and ammonia formation. In the present study, mostly woody plants, such as the leaves of trees and shrubs, were tested for their influence onin vitrofermentation. The plants selected grow naturally under temperate climatic conditions, are usually available in bulk and do not directly compete with human food production. The detailed screening included whole plants or parts of different plant species reporting their effects on methane and/or ammonia formation. The plant materials were added at 167 mg/g of total dry matter (DM) to a common total mixed ration and incubated for 24 h with the Hohenheim gas test method. The results fromin vitrofermentation were also used to determine the net energy of lactation and utilizable crude protein in the complete diets. Thirteen out of 18 test materials did not impair the organic matter (OM) digestibility of the diet. Ammonia concentrations decreased up to 35% when adding any of the test materials. Methane formation per unit of feed DM and per unit of digestible OM was lowered by 13 of the 18 test materials from 12 to 28% and 5 to 20%, respectively. In conclusion, a number of plant materials tested have the potential to mitigate ruminal ammonia and methane formation without adversely affecting digestibility. The leaves ofBetula pendula,Corylus avellana,Ribes nigrum,Vitis viniferaand the aerial part ofGeum urbanumwere particularly promising in this respect.