Date of Graduation


Document Type


Degree Name

Doctor of Philosophy in Animal Science (PhD)

Degree Level



Animal Science


Charles V. Maxwell

Committee Member

Gisela F. Erf

Second Committee Member

Elizabeth B. Kegley

Third Committee Member

Charles F. Rosenkrans


Biological sciences, Litter, Nursery pig, Nutritional modifications, Pichia guilliermondi, Sow, Yeast product


Two separate series of experiments were conducted to determine: 1) the influence of dietary arginine supplementation in late gestation on reproductive performance, and 2) the impact of a whole yeast product in gestation, lactation, and weaned pig diets on reproductive, growth, and immune parameters.

In the first study 99 sows were provided a control diet, or the control diet supplemented with 1% L-arginine from gestation d 93 to 110. Compared to control-fed sows, no differences were observed in reproductive parameters, however a tendency for increased gestational weight gain was observed for sows provided supplemental arginine.

In a second study, 98 sows were provided a control diet, or the control diet supplemented with 0.1 or 0.2% CitriStim (whole yeast product, Pichia guilliermondii [Pg]) through gestation and lactation. Additionally, two separate nursery studies were conducted in a 3 (sow treatments) × 2 (nursery with or without Pg) factorial arrangement. Pigs were challenged with lipopolysaccharide in a sub-study during the second nursery study. Supplementation with Pg increased number born alive, number weaned, and preweaning mortality, and decreased the number born weighing less than 0.9 kg compared to the control diet. Additionally, total neutrophils and the neutrophil:lymphocyte ratio were increased in sows receiving diets supplemented with Pg. In the first nursery study, pigs from sows fed Pg supplemented diets, but not from control sows, had increased ADG, ADFI, and BW in a linear fashion in phase 1 when Pg was also fed to weaned pigs (interaction; P < 0.05). In several instances an additive effect of Pg supplementation to sow diets and nursery diets was observed. Additionally, linear increases in weaned pig growth performance were observed in the second nursery study as the level of Pg inclusion increased in gestation/lactation diets. Supplementation of sow diets with Pg improved feed intake following LPS challenge in weaned pigs and altered the febrile and immune response compared to pigs from sows fed control diets. In conclusion, Pg in sow and nursery diets improved sow reproductive performance, weaned pig performance, impacted immune parameters and altered immune response to LPS stimulation.