Connecting Molecular Characteristics of Intrauterine Growth-Retarded Piglets to Targeted Nutritional Interventions: A Review

Abstract

Intrauterine growth retardation (IUGR) is highly prevalent in modern swine production, and many affected piglets survive past weaning and are raised for commercial pork production. This review summarizes the current understanding of the physiological challenges of IUGR piglets from a molecular perspective and evaluates recent advances in nutritional strategies aimed at mitigating their negative outcomes. Molecular approaches, including omics technologies and targeted analyses, have been employed to investigate the physiological characteristics of IUGR piglets. These approaches consistently show that IUGR piglets exhibit systemic dysfunction, including compromised gut health, increased inflammation and oxidative stress, and impaired function of multiple organs such as the intestine, liver, kidney, and immune-related tissues. Moreover, IUGR piglets often display poor muscle development and meat quality. The multifactorial nature of these issues suggests that targeting a single physiological parameter may be insufficient, and comprehensive interventions are needed to address the widespread effects of IUGR. Promising nutritional strategies such as supplementation with polyphenol-rich plant extracts, amino acids, and probiotics have demonstrated potential in improving gut integrity, beneficially modulating microbiota, and enhancing the overall health and performance of IUGR piglets. By supporting the systemic recovery of IUGR piglets, nutritional interventions could improve overall productivity in swine production systems.

Keywords: IUGR piglets; and meat quality; gut health; molecular analysis; omics; oxidative stress; swine production.

Figure 1

Characteristics of intrauterine growth retarded (IUGR) piglets: One of the most recognizable features of IUGR is their distinct head shape, often described as a “dolphin-like” profile. Pictures were taken in New Deal Swine facility at Texas Tech University, Lubbock, Texas.

Figure 2

Interconnected and direct effects of IUGR on gut and systemic health in piglets. IUGR can directly impair multiple aspects of gut and systemic health including gut microbiota, intestinal barrier integrity, inflammation, oxidative stress, and organ function. These parameters are also closely interconnected, amplifying the overall impact. IUGR alters the gut microbiota by decreasing commensal bacteria and beneficial metabolites while increasing pathogenic bacteria and bacterial toxins. These microbial changes weaken gut barrier function by reducing tight junction protein expression, leading to increased intestinal permeability. The subsequent translocation of harmful microbial products contributes to immune dysregulation and elevated oxidative stress, which, in turn, impairs the function of vital organs and skeletal muscle.