Nathalie L. Trottier, PhD
Professor, Department of Animal Science, Michigan State University
Luis Tedeschi, PhD
Professor, Department of Animal Science, Texas A& M University
Amino acids required for biological processes are obtained from dietary protein that is digested in the gastrointestinal tract, and subsequently been absorbed into the bloodstream and further metabolized to support distinct metabolism related to maintenance and productive functions. Requirements for amino acids, therefore, represent the sum of those used for maintenance and retained in the body (e.g., growth or pregnancy) or excreted into milk. Nitrogen and individual amino acid requirements (except for lysine) of the gestating and lactating mare have not been systematically determined. Thus, characterizing the determinants of requirements by extrapolation from existing models in other species is an important step to begin defining amino acid requirements for the mare. Determinants of individual amino acid requirements for maintenance, gestation, and lactation required to develop predictive models for the mare will be discussed. Available literature and data gaps will be highlighted to guide recommendations for future research needed to refine the nitrogen and amino acid requirements of the mare through modeling.