Do-Yon Lee

Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Animal Science


Three experiments were conducted to evaluate the effect of diet composition on the response of newly weaned pigs to zinc oxide and antimicrobial agents and nutrient digestibility. All pigs were weaned between 21 and 28 days of age and allotted to dietary treatments on the basis of weight, sex and ancestry to randomized complete blocks. In experiment (EXP) I, the efficacy of adding pharmacological levels of Zn ( as ZnO) or apramycin sulfate (APR) to simple or complex (phase I) starter diets was studied for 28 days. A split-split plot design was used. A total of 258 pigs (7.1 kg) were weaned in two groups with each group assigned to 24 pens at different nursery sites (whole-plot). Diets (sub-plots) were simple containing corn, soybean meal, and 20 % dried-whey or phase I containing these ingredients plus 10 % lactose and 6 % spray-dried porcine plasma. All diets were formulated for 1. 4 % lysine and at least 100 ppm added Zn. Additions to these diets of no additional Zn or APR, 3000 ppm Zn, or 75 ppm APR were the sub-sub plots. Plasma urea N (PUN) and plasma Zn concentration (PZC) were determined on d 10 and d 20. From d 10 to d 14, feeding phase I diets increased ADG (269 vs 184 g/d), ADFI (346 vs 254 g/d) and d 10 PZC (107 vs 81 ppm) and reduced d 10 PUN (6.20 vs 11.56 mg/di) compared with simple diets (P < .01). Similar results were noted from d Oto 28. Added Zn resulted in greater overall ADG (413, 373 and 346 g/d) and ADFI (577, 527 and 498 g/d) than feeding APR or the basal diets (P < .01). A diet x additive interaction occurred (P < .01) for ADG. Pigs fed a simple diet with added Zn or any phase I diet had similar (P > .10) ADG (d Oto 14 and d Oto 28). Pigs fed added Zn had lower PUN (7.54, 10.36 and 8. 73 mg/dl) than pigs fed APR or the basal diets on d IO (P < .07). Added Zn resulted in higher PZC on d 10 {148, 70 and 64 ppm) and d 20 {175, 85 and 68 ppm) than feeding APR or the basal diets (P < .01). In EXP 2, the additive effect of Zn with carbadox (CAR) on the response of growth performance to simple starter diets for weaned pigs was studied. One hundred twenty pigs averaging 7.9 kg were allotted to dietary treatments. A 2 x 2 factorial arrangement of the simple diets was used, and non-orthogonal contrasts were used to compare between simple and complex diets. Four of six diets were simple, and two additional diets were complex (phase I and Il). Main ingredients in simple and phase I diets were similar to EXP I. Dietary treatments were (I) simple basal, (2) simple + 3 000 ppm Zn, (3) simple+ 55 ppm CAR, (4) simple+ 3000 ppm Zn+ 55 ppm CAR, (5) phase I basal and (6) phase I+ 55 ppm CAR. Pigs fed phase I diets for 14 d postweaning followed by phase II diets containing 2 % blood meal (1.2 % lysine) from d 15 to 28. From d 0 to 14, pigs fed simple diets with added Zn had greater ADG (276 vs 153 g/d)

Library of Congress Subject Headings

Swine --Feeding and feeds

Zinc oxide

Anti-infective agents



Number of Pages



South Dakota State University



Rights Statement

In Copyright