The nutritional value of a new type of soybean meal for chickens and pigs and the impact of reducing soybean meal inclusion in diets for growing pigs

Cristobal Romero, Minoy Augusto

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https://hdl.handle.net/2142/129441 Copy

Description

Title

The nutritional value of a new type of soybean meal for chickens and pigs and the impact of reducing soybean meal inclusion in diets for growing pigs

Author(s)

Cristobal Romero, Minoy Augusto

Issue Date

2025-04-30

Director of Research (if dissertation) or Advisor (if thesis)

• Stein, Hans H
• Parsons, Carl M

Doctoral Committee Chair(s)

• Stein, Hans H
• Parsons, Carl M

Committee Member(s)

• Swanson, Kelly S
• Harsh, Bailey N

Department of Study

Animal Sciences

Discipline

Animal Sciences

Degree Granting Institution

University of Illinois Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• soybean meal
• amino acids
• pig
• chicken
• metabolizable energy
• net energy

Abstract

Ten experiments were conducted with the objective of testing 3 hypotheses: (1) soybeans can be genetically improved without negatively affecting the nutritional value of the meal for poultry or pigs; (2) dietary protein can be reduced by reducing soybean meal (SBM) inclusion while supplementing with synthetic amino acids (AA) without affecting growth performance of pigs; (3) dietary protein does not influence net energy (NE) in corn-SBM diets fed to growing pigs. In experiments 1, 2, and 3, the objective was to compare the nitrogen-corrected true metabolizable energy (TMEn), standardized AA digestibility, and apparent ileal P digestibility between soybean expellers from high-oil soybeans (SBE-HO) and conventional soybeans (SBE-CV). Results demonstrated that SBE-HO had greater (P < 0.05) TMEn (3.261 kcal/g DM) compared with SBE-CV (3.162 kcal/g DM), but AA digestibility was not different. However, SBE-HO had greater (P < 0.05) concentrations of some digestible AA. In broiler chickens, the apparent ileal P digestibility was not different between SBE-CV (46.8%) and SBE-HO (40.6%). In experiments 4, 5, and 6 the objective was to test the hypothesis that standardized ileal digestibility (SID) of AA, metabolizable energy (ME), and standardized total tract digestibility (STTD) of P in SBE-HO are not different when compared with SBE-CV. Results indicated that whereas SID of some indispensable AA (Arg, Ile, and Lys) did not differ between the two types of soybean expellers, other AA had greater (P < 0.05) digestibility in SBE-CV than in SBE-HO, although SBE-HO had greater (P < 0.05) concentrations of digestible AA. No differences in ME were observed between SBE-HO and SBE-CV. Inclusion of microbial phytase improved P digestibility, but STTD of P was not different between SBE-CV and SBE-HO. It was concluded that SBE-HO, due to higher concentrations of digestible indispensable AA, requires slightly less inclusion than SBE-CV without affecting ME or STTD of P. In experiment 7, the objective was to test the hypothesis that feeding intact protein from SBM to growing pigs instead of a combination of SBM and synthetic AA results in greater nitrogen retention and DE without affecting ME in the diet. Results indicated that reducing SBM inclusion and replacing with synthetic AA and corn resulted in a decrease (linear, P < 0.05) in apparent total tract digestibility of dry matter and gross energy, as well as a reduction (linear, P < 0.05) in absorbed and retained nitrogen. However, nitrogen retention efficiency improved (linear, P < 0.05) when synthetic AA were used. The DE in diets also decreased (linear, P < 0.05) with reduced SBM inclusion, whereas ME was unaffected. In experiment 8, the objective was to test the hypothesis that reducing dietary protein in corn-SBM diets will not increase diet NE and will not affect growth performance, carcass composition, nutrient deposition, intestinal morphology, blood cytokine concentrations, or the abundance of genes for intestinal AA transporters. Results indicated that reducing SBM inclusion and adding synthetic AA did not affect average daily gain, feed intake, carcass characteristics, or nutrient deposition. Whereas blood urea nitrogen decreased (linear, P < 0.05) with reduced protein, other blood components, intestinal morphology, and abundance of AA transporter genes were unaffected by dietary treatment. Net energy in diets tended to decrease (linear, P < 0.10) with reduced crude protein levels, and bacterial protein in the colon decreased (linear, P < 0.05). It was concluded from the experiment that reducing dietary protein did not impact growth, blood markers, intestinal morphology, or NE in diets. In experiments 9 and 10, two experiments were conducted to test the hypothesis that diet protein concentration does not affect apparent ileal digestibility (AID) of starch, SID of AA, or NE in diets fed to growing pigs. Results indicated that AID of starch was unaffected by dietary protein, whereas SID of protein and all AA increased (linear, P < 0.05) as dietary protein was reduced. Results also indicated that NE, which was measured using indirect calorimetry, did not change as dietary SBM was reduced and inclusion of synthetic AA and corn increased, whereas DE and ME decreased (linear, P < 0.05) with reduced dietary protein. In conclusion, reducing protein in diets did not influence starch digestibility, but improved the SID of indispensable AA, and overall did not influence NE in diets fed to growing pigs. Overall, results of the ten experiments indicated that soybeans can be genetically improved without negatively affecting the nutritional value of the meal for poultry or pigs. It is also concluded that if dietary protein is reduced by reducing SBM inclusion and increasing the inclusion of corn and synthetic AA, growth performance of pigs and NE of diets are not influenced, but nitrogen retention is reduced indicating reduced protein synthesis in pigs fed diets with reduced protein.

Graduation Semester

2025-05

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/129441

Copyright and License Information

Copyright 2025 Minoy Augusto Cristobal Romero

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