Identifying forage mixtures for a better balance between rapidly fermentable carbohydrates and rumen degradable proteins
Plant Science Seminar, live on Zoom. Xavier Godin, MSc Research Proposal
Feeding unbalanced forages that are high in nitrogen (N) and low in carbohydrates to ruminants can be detrimental for agricultural producers, both environmentally and economically. Nutritionally unbalanced forages are associated with potentially high N losses as the rumen microbiome may be unable to assimilate efficiently the N present in forages if there is insufficient energy provided by carbohydrates. Therefore, to improve N efficiency, it is necessary to balance the amount and the availability in the rumen of both carbohydrates and protein fractions of forage fed to ruminants. Two ratios of carbohydrates to proteins are predominantly used to assess this balance: i) water-soluble carbohydrates over crude proteins, and ii) mono and oligo-saccharides + starch over non-protein N + rapidly degradable proteins. Increasing these ratios in forages will allow for a better N utilization by the microbial population of the rumen. A project has been established at three contrasting sites in Canada to assess if changes in forage species used in mixtures can be a mean of increasing carbohydrate to protein ratios. The experiment contains twenty-one different treatments composed of combinations of three different forage legumes (alfalfa, red clover, and birdsfoot trefoil) in different proportions and three different grass treatments (timothy, tall fescue, or no grass). The above ratios along with other nutritive attributes will be measured to identify mixtures with the highest N efficiency potential.
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