Researchers predict a world population of approximately 9.5 billion people by the year 2050. Current resources, including the amount of meat that is produced, would not be able to sustain that population. Therefore, the current dissertation research was completed to assist in improving reproductive efficiency. A third of pregnancies are “lost”, or spontaneously aborted with unknown reason(s). Therefore, research has been directed towards improving reproductive efficiency, especially in regards to proper ovarian function in both pregnant and non-pregnant females. Numerous factors influence reproduction including hormones, growth and angiogenic factors, nutritional plane, and supplements such as arginine (Arg), a semi-essential amino acid and precursor for proteins, polyamines, and nitric oxide (NO). Nitric oxide is a reactive gas molecule made naturally in the body and is critical for angiogenesis, which is the development of blood vessels, generally capillaries, from pre-existing blood vessels to allow for blood flow to specific tissues. During a female’s reproductive cycle, certain reproductive tissues undergo rapid changes including vascular development and regression, and tissue growth and regression. One of those tissues, the corpus luteum (CL), is critical for pregnancy as the tissue produces progesterone (P4), a pregnancy maintenance hormone. Therefore, the objective of this research was to investigate how manipulation of the NO system via Arg supplementation to nutritionally compromised ewes impacts ovarian function and endocrine activity in non-pregnant sheep.