ARS/SCA: Effects of dietary crude protein on fertility in mares

1. Determine changes in plasma urea nitrogen and uterine pH in mares after administration of oral or intravenous urea. 2. Determine changes in the endometrial transcriptome and serum progesterone concentrations in mares fed a high versus low crude protein diet. 3. Examine the relationship between plasma urea nitrogen concentrations and pregnancy rates at Days 14 to 18 as well as subsequent embryonic loss rates in mares in central Kentucky.