Effects of feed with different protein digestion kinetic profiles on intestinal health of growing pigs

M.R Thandavhathu,Q Zhang,Z.W Shen,Y Zhao,B Wang,G Qin

doi:10.4314/sajas.v51i4.12

M.R Thandavhathu, Q Zhang + Show 4 more

Open Access

https://doi.org/10.4314/sajas.v51i4.12

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Abstract

This study evaluated the effects of feed ingredients with different protein digestion kinetic profiles on the intestinal health of growing pigs. Two protein sources were selected, namely casein (CAS) as a rapid release source of amino acids (AAs), and corn gluten meal (CGM) as a slow-release source. Twenty-four crossbred barrows (Duroc × Landrace × Yorkshire) with similar bodyweight (43.27 ± 3.51 kg) were selected and randomly assigned to four treatments with six barrows. These consisted of T1: 13.2% digestible crude protein (CP) with supplemental CAS; T2: 13.2% digestible CP with supplemental CGM; T3: 11.2% digestible CP with supplemental CAS (T3); and T4: 11.2% digestible CP with supplemental CGM. Diets with CGM had increased crypt depth in the duodenum, jejunum, and ileum and reduced villi height in the jejunum in comparison with CAS. They also had increased intestinal permeability, as seen by the high level of serum diamine oxidase (DAO) compared with CAS. The diets with CAS increased health-promoting Lactobacillus and decreased health-threatening Treponema compared with those fed CGM diets. The CAS diets had a positive effect on gut functions with increased villi height, decreased crypt depth and high villi height/crypt depth. Thus, use of CAS in diets for pigs is favoured over CGM.

Highlights

Several properties of protein sources can affect the release kinetics of free amino acids (AAs) and dipeptides and tripeptides
Pigs fed diets containing CAS had increased villi height and villi height/crypt depth in the duodenum, jejunum and ileum compared with those fed corn gluten meal (CGM)
As a result of the various sources of AAs, CGM was found to increase crypt depth in the duodenum, jejunum, and ileum compared with CAS

Summary

Introduction

Several properties of protein sources can affect the release kinetics of free amino acids (AAs) and dipeptides and tripeptides. This may influence the timing of the postprandial appearance of AAs and peptides (Chen et al, 2018). Dietary proteins need to be hydrolysed into free AA or small peptides (Ganapathy et al, 2000; Webb et al, 1992) before they can be absorbed by enterocytes in the small intestinal mucosa. The absorption of AAs, and di- and tripeptides by intestinal enterocytes takes place in the jejunum and ileum, for which the proximal jejunum is the major site (Bröer, 2008; Chen, 2017). Pigs have a longer retention time of digesta in the stomach and the small intestine than poultry (Liu et al, 2013; Weurding et al, 2001; Wilfart et al, 2007)

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