INFLUENCE OF LEVEL OF ENERGY AND NUTRIENT INTAKE BY MARES ON REPRODUCTIVE PERFORMANCE AND ON BLOOD SERUM COMPOSITION OF THE MARES AND FOALS

An experiment, conducted at Olds College, involving seven pregnant and five open half-Arabian (half-sib) mares had the primary objective of evaluating the adequacy of National Academy of Sciences–National Research Council (NAS–NRC 1973) nutrient requirements of horses as they applied to mares receiving minimal shelter under central Alberta winter conditions. Mares were randomly assigned to two groups, the first receiving a diet formulated to meet NAS–NRC requirements and the second the same diet at a level of 85% of the former by weight. The dietary regimen was maintained from mid-gestation until 30-days post-partum. No significant (P