Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Animal Science


anti-nutritional factors, digestibility, growth performance, intestinal permeability, soybeans, weaned pig


Soybeans are the ‘gold standard’ protein source in pig diets, with lower inclusion levels in weaned pig diets due to transient inflammatory and hypersensitivity responses. This study evaluated a low allergenic (LA) soybean seed containing low Trypsin inhibitors, lectins, and P34 protein. The objective was to determine the impact of weaned pig diets containing LA soybean in both meal (LASBM) and full fat ground (LAGR) forms on the intestinal permeability and gut microbial composition, digestibility of protein and amino acids, and growth performance, in comparison to conventional (CON) soybeans and animal proteins (ANIM). In study 1, 60 weaned barrows (20.9 ± 1.0 d of age, 6.65 ± 0.3 kg, n=12/diet) were randomly assigned to one of five experimental diets containing one of 5 test proteins (CONSBM, CONGR, LASBM, LAGR and ANIM). Gut permeability measurements (Ussing Chambers and lactulose:mannitol ratio) were collected over 4d (1 pig/diet/d), beginning at d 11. No differences were detected in ileal or jejunal permeability among dietary treatments. Pigs fed ANIM had highest (P < 0.05) urine lactulose:mannitol ratio. Daily gain and feed disappearance were greatest (P < 0.05) for pigs fed ANIM-based diets. There were no differences in taxonomy or relative abundance of operational taxonomic unit’s (OTU’s) in digesta microbial content. In Exp. 1 of study 2, 10 ileal-cannulated barrows (17.63 ± 1.18 kg BW) were used in a cross-over design and randomly assigned to one of five experimental diets (FM, CONSBM1, LASBM, LAGR and nitrogen-free), where the test ingredients were included as the sole protein source, to determine standardized ileal digestibility. Each pig received 3 of the 5 diets (1 diet/collection period; n = 6 per diet). In Exp. 2, the methods used in Exp. 1 were replicated, except 5 barrows and 5 gilts were used (19.40 ± 1.65 kg). In Exp. 1, SID of CP and AA was greater (P < 0.05) in FM than soy products. There were minor differences in digestibility between soy products where SID of LYS, MET, and HIS were greater (P < 0.05) in LASBM than CONSBM1. In Exp. 2, SID of CP and AA was similar between FM and CONSBM2 and lower (P < 0.05) in LASBM and LAGR than FM and CONSBM2. Overall SID tended (P < 0.10) to be lower in gilts than barrows. Growth performance was determined in 112 weaned pigs (7.30 ± 0.43 kg BW; 2 barrows and 2 gilts per pen; study 3) assigned to one of four dietary treatments in 2 phases (Ph1 = 5d, Ph2 = 13d). The control diet contained FM (7.25%, Ph1; 6%, Ph2); LASBM, LAGR and VOLGA-SBM replaced FM to supply equivalent dietary crude protein. Pigs received a common Ph3 diet (18d). Overall daily gain was greater (P < 0.01) in LAGR-fed pigs compared to LASBM, but not different from FM- or SBM-fed pigs; daily gain tended to be greater (P < 0.10) in SBM- than FM-fed pigs. Overall daily intake tended to be greater (P < 0.10) in SBM-fed pigs compared to FM and LASBM but was not different from LAGR. There was a tendency for greater (P < 0.10) overall G:F in LAGR- versus LASBM-fed pigs. Low allergenic soybean products may be considered a replacement for CON soybean products in weaned pig diets due to their similarity in gut permeability, digesta microbial content and similar growth performance. LAGR does not impact pig performance and could serve as a suitable replacement to FM in weaned pig diets.

Library of Congress Subject Headings

Swine -- Feeding and feeds.
Soybean products.
Swine -- Physiology.
Swine -- Growth.
Intestines -- Microbiology.



Number of Pages



South Dakota State University



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In Copyright