Objective:
The objective of this trust is to quantify the effectiveness of feeding the isobutyl ester of 2-hydroxy, 4-methylthio butyrate (aka HMBi), a methionine supplement sold commercially by Adisseo as MetaSmart®. Feeding this supplement may allow dairy cows to be fed less dietary crude protein without lowering production. If successful in practice, then urinary nitrogen output, the most polluting form of excretory nitrogen, would be reduced.

Approach:
In vitro studies will be conducted using batch cultures of mixed ruminal microorganisms to assess effects of methionine, HMB and HMBi on kinetics of ammonia uptake, total amino, and VFA concentration patterns, organic matter and NDF digestion, microbial protein formation, and protozoal numbers. A large-scale in vivo study will be conducted with lactating dairy cows which are fed a low-protein diet based on typical feeds to determine the effects of supplementing HMB, HMBi, or rumen-protected methionine on milk production, nitrogen efficiency, and ruminal metabolism.