Date of Graduation


Document Type


Degree Name

Master of Science in Animal Science (MS)

Degree Level



Animal Science


Charles Maxwell

Committee Member

Craig Coon

Second Committee Member

Rick Rorie


Cottonseed, Gossypol, Organic Acids, Peptides, Swine, Zinc Oxide


To evaluate the effects of peptide in combination of zinc oxide (Zno) or acidifiers (Exp 1), and gossypol (G) from cottonseed meal (CSM) ( Exp 2&3) on growth performance, complete blood cell counts (Exp 1, 2&3), nutrient digestibility (Exp 1), plasma gossypol (Exp 2&3) and semen quality (Exp 3), weaned pigs (Exp 1), growing gilts (Exp 2) and growing boars (Exp 3) were randomly allotted to dietary treatments. Treatments for Exp 1 during phase 1&2 were: (1) Positive Control (PC), formulated to meet NRC (2012) nutrient requirements; (2) Negative control (NC), fish meal was reduced to achieve -0.13% SID lysine; (3) NC + 0.25% peptide plus high level of zinc (0.25PZ); (4) NC + 0.50% peptide plus high level of zinc (0.5PZ); (5) 0.25% peptide (0.25P); (6) 0.50% peptide (0.5P); (7) 0.25% peptide + 0.1% sodium butyrate and 0.5% benzoic acid (PSB). In phase 3, all pigs were fed a common diet. Treatments in Exp 2 during phase 1 to 3 consisted of: (1) control diet, formulated to meet NRC, (2012) nutrient requirements without CSM (0% G); (2) inclusion of 1.21% CSM (0.01% G); (3) 2.42 % CSM (0.02% G); and (4) 4.84 % CSM (0.04% G). In Exp 3, dietary treatments were the same as those in Exp 2, except the 1.21% CSM (0.01% G) was removed. During phase 4, pigs were fed a common diet devoid of CSM (Exp 2&3). Each phase consisted of 14 days. Data were analyzed using the Mixed procedures of SAS as a RCBD with treatment as fixed effect, and BW block as random effect. In overall phase 1&2 of Exp 1, PSB pigs had similar ADG and BW when compared to those fed 0.25PZ and both were greater than NC pigs (P < 0.05). In Exp 2&3, gilts had a linear reduction (P < 0.05) and boars a quadratic ADG response (P < 0.05) as level of CSM increased in the diet during phase 3. These studies demonstrate that feeding nursery pigs with peptide in combination with acidifiers improved growth performance similar to that observed in pigs fed high levels of zinc oxide, indicating that acidifiers may be an alternative to high levels of ZnO in weaned pigs diets without affecting their growth performance. Feeding gossypol from CSM up to 0.02% impaired growth performance in gilts and boars but not affected semen quality.