Plant polysaccharides show promise in early-weaned squabs

Plant polysaccharides are getting another look as functional feed additives, this time in early-weaned squabs. In a newly listed Animals study, researchers found that Astragalus polysaccharide and Glycyrrhiza polysaccharide, used alone or together, improved several immune and antioxidant markers in artificially reared young pigeons, with the combined treatment showing some of the strongest effects. The work adds species-specific data to a feed-additive category that has been studied far more extensively in pigs and broilers than in squabs. (mdpi.com)

That context matters because squab production has a distinct nutritional challenge. Unlike chickens, newly hatched squabs depend on parent-fed crop milk and are especially vulnerable when weaned early or moved to artificial feeding systems. Prior studies have linked early weaning in pigeons to intestinal microbiota disturbance, mucosal barrier dysfunction, inflammation, and poorer gut integrity, which helps explain why producers and researchers are testing feed-based strategies to blunt that stress response. Reviews of squab production also describe nutrition, gut microbiota, and disease prevention as major drivers of growth performance in this species. (pmc.ncbi.nlm.nih.gov)

In the new trial, 192 15-day-old Silver King squabs were randomized into four groups: control, 800 mg/kg APS, 450 mg/kg GPS, and a combined APS+GPS group, with the experiment running for 28 days. Final body weight only trended upward, but breast width and breast depth increased significantly in the GPS and combination groups. The researchers also reported higher serum IgA and IgG in the GPS and combined groups, lower pro-inflammatory cytokines, and higher serum total antioxidant capacity across all treatment groups. The combined treatment reduced serum malondialdehyde and increased total superoxide dismutase and glutathione peroxidase, while jejunal lipase activity also rose in that group. (mdpi.com)

The gut findings were more nuanced. The paper says duodenal and jejunal total antioxidant capacity increased in all treatment groups, and ileal total antioxidant capacity increased with APS and the combined diet. At the same time, some intestinal segments showed higher malondialdehyde concentrations, which the authors characterized as a complex, segment-specific oxidative response rather than a uniformly protective effect. On the microbiome side, Lactobacillus emerged as an important core genus in the co-occurrence network, while Helicobacter correlated with immune-related indicators. That kind of mixed signal is important for clinicians and nutrition advisers: the additives appear biologically active, but the mechanism and consistency of benefit still need clarification. (mdpi.com)

There does appear to be broader biological plausibility behind the findings. Research in broilers and weaned piglets has previously linked APS, GPS, and other plant polysaccharides with improved antioxidant enzyme activity, immune markers, intestinal morphology, and microbial composition. A broiler study on compound Astragalus and Glycyrrhiza polysaccharides reported gains in growth performance, meat quality, antioxidant function, and cecal microbiota, while other poultry work has tied Astragalus-driven microbiota changes to stronger intestinal barrier function. Those cross-species results don't prove the same commercial value in pigeons, but they do suggest the squab findings fit an emerging pattern rather than standing alone. (pubmed.ncbi.nlm.nih.gov)

Why it matters: For veterinary professionals, especially those supporting niche avian production, this study highlights a possible nutrition-based tool for managing one of the most fragile points in the squab production cycle. If plant polysaccharides can reliably reduce inflammatory stress and support gut adaptation after early weaning, they could become part of broader health programs aimed at improving survivability, feed efficiency, and flock uniformity. But the evidence is still early. The study was conducted under controlled conditions, focused on biomarker and morphometric outcomes more than hard field endpoints, and did not establish whether these changes translate into lower mortality, reduced disease burden, or better economics at scale. (mdpi.com)

Another practical point is that the paper evaluates feed additives in a production model that is itself under scrutiny. Recent work on early weaning in pigeons suggests timing and management can materially affect both squab performance and intestinal health, meaning additive strategies may ultimately need to be evaluated alongside weaning age, artificial crop milk formulation, hygiene, and stocking practices. In other words, APS and GPS may be helpful, but they probably won't be a standalone fix for poor early-life management. (pubmed.ncbi.nlm.nih.gov)

What to watch: The next step is validation in commercial settings: larger trials, clearer dose-response work, and outcome measures that matter in practice, including mortality, feed conversion, enteric disease pressure, carcass quality, and cost-effectiveness. It would also be useful to see whether the combination of APS and GPS consistently outperforms either additive alone, and whether microbiome shifts such as Lactobacillus enrichment hold up across different breeds, diets, and weaning protocols. (mdpi.com)