Dietary Insect Powder Protein Sources Improve Protein Utilization by Regulation on Intestinal Amino Acid-Chemosensing System.

Hongnan Liu,Guangran Li,Liuqin He,Jianjun Li,Yulong Yin,Bie Tan,Xiangfeng Kong,Miaomiao Bai

doi:10.3390/ani10091590

Abstract

Simple SummaryInsect powders, including Tenebrio molitor (TM), Musca domestica larvae (MDL) and Zophobas morio (ZM), as high-quality and renewable protein sources are commonly applied in livestock and poultry feed production. The molecular effect of insect protein on amino acid metabolism in pigs needs to be explored. We found that insect powder as a protein source in feed regulated the mTOR signal pathway and improved amino acid transportation in the intestine for growth promotion. Insect powder may be a potentially promising protein source for pig production.This study was conducted to evaluate the effects of dietary insect powder supplementation as a protein source on plasma amino acid profiles, intestinal amino acid transport and sensing in a piglet model. A total of 144 weanling piglets were randomly assigned to four experimental diets for two phases (Days 1–28 and Days 29–56), to assess the effects on amino acid profiles and transportation in the segments of the intestine. The groups were basal diet (control), control diet plus Tenebrio molitor (TM), control diet plus Musca domestica larvae (MDL) and control diet plus Zophobas morio (ZM). The plasma free amino acid levels were stable comparable among treatments, except that the lysine level was significantly reduced by dietary MDL and ZM supplementation in the first phase (p < 0.05). In the 1st phase, the sensitivity of intestinal segments to the regulation of the amino acid level by insect powder supplementation follows sequence: colon > ileum > jejunum, while the order switched to jejunum > colon > ileum in the 2nd phase. The relative RNA expressions of mitogen-activated protein 4 kinase 3 (MAP4K3), sodium dependent neutral amino acid transporter2 (SNAT2), the transient receptor potential cation channel subfamily V member 1 (TRPV1) and taste 1 receptor member 1/3 (T1R3) in the segments of the intestine were affected by different dietary insect powder supplementation. G protein-coupled receptor family C group 6 member A (GPRC6A) level in the jejunal and colonic mucosa was upregulated by MDL supplementation (p < 0.05). These results indicated that dietary insects improved the metabolism of the amino acid in the prophase (the 1st phase) through regulating the sensing gene and mTOR signal pathway in intestinal mucosa by targeting different receptors. The finding demonstrates that the insect powder is a potentially promising source for protein deposition.

Highlights

Protein deposition relies on the use of a high-quality protein diet
The plasma Val level in pigs fed the Tenebrio molitor (TM) diet was higher than that fed the Musca domestica larvae (MDL) and Zophobas morio (ZM) diets (p < 0.05)
In the 2nd phase, the result showed that dietary insect powder supplementation changed the level of Cys, Ile and Lys in the plasma, whereas Cys content in the ZM group was increased significantly compared to the control group (p < 0.05)

Summary

Introduction

Protein deposition relies on the use of a high-quality protein diet. A high-quality protein source must have adequate amino acid distribution and high digestibility, as well as high content protein [1].Insects can turn low-grade biowaste into high quality proteins indicating that insects as a renewable protein rich feed ingredient is technically feasible. [2]. Protein deposition relies on the use of a high-quality protein diet. A high-quality protein source must have adequate amino acid distribution and high digestibility, as well as high content protein [1]. Insects can turn low-grade biowaste into high quality proteins indicating that insects as a renewable protein rich feed ingredient is technically feasible. Insect protein appears as a potentially suitable ingredient with several characteristics that make it relevant for its use in the diet, such as its high protein level [6], good amino acid profile [7] and its characteristics in terms of secure supply with less environmental impact [8]. Insects can be reared on low-grade biowaste and can turn biowaste into high-quality proteins. The molecular effect of dietary insects on amino acid transportation is not well known

Methods

Results

Conclusion