Date of Graduation


Document Type


Degree Name

Master of Science in Animal Science (MS)

Degree Level



Animal Science


Charles Maxwell

Committee Member

Craig C. Coon

Second Committee Member

Jason Apple


complete blood cell count, fermented soybean meal, growth performance, nursery pig, nutrition, pig diet, pig production, sodium butyrate


To evaluate increasing levels of sodium butyrate (SB) in nursery diets on growth performance (Experiment 1 & 2), complete blood cell count (Experiment 2), and the optimal level of fermented soybean meal for maximum performance in weanling pigs (Experiment 3), weaned pigs were blocked with initial body weight (BW) and allotted to dietary treatments. Treatments were: 1) Control (C) moderately complex corn-soybean-meal based supplemented with 0.05% benzoic acid (BA), but devoid of SB; C diet supplemented with 0.05%, 0.10%, or 0.15% SB (Experiment 1). Treatments in experiment 2 consisted of 1) a moderately complex corn-soybean-meal based diet devoid of SB and BA (NC), 2) The NC diet supplemented with 0.5% BA, 3, 4 and 5) NC diet supplemented with 0.5% BA and 0.05%, 0.10% or 0.15% SB, respectively. Treatments in experiment 3 consisted of 1) a fermented soybean protein-poultry by-product diet (C), 2, 3, and 4) C diet was replaced with 5%, 10%, or 15% fermented soybean meal, respectively (FSBM; Experiment 3). Blood was collected at the beginning and end of each phase to determine complete blood cell count (Experiments 2 & 3). Data were analyzed by MIXED procedures of SAS (SAS Inst., Cary, NC) with dietary treatment as a fixed effect, while facility by treatment interactions (Experiment 1 & 2) and initial BW blocks as random effects (all experiments). In exp. 1 & 2, increasing dietary SB increased weight gain (P < 0.05), ADFI (P ≤ 0.05), and final BW (P < 0.05). For exp. 2, total white blood cell (P = 0.07) and eosinophil cell count increased with increasing SB (P = 0.08). Lymphocyte cell count decreased (P = 0.09) with increasing SB. In exp. 3, with increasing FSBM in the diet, overall feed efficiency (d 0-40; P = 0.07) increased, and ADG (P = 0.05) and ADFI (P = 0.04) increased during phases 1 & 2 (d 0-29). The heaviest BW was observed in pigs fed 10% FSBM on d 29 (P = 0.06), but the difference diminished by the end of the trial. Pigs fed 10% FSBM had the lowest WBC, neutrophil, and red blood cell count. These experiments suggest that feeding SB and 10% FSBM during the nursery phase improves growth performance and alters blood cell characteristics in weanling pigs.