Effects of Lactobacillus spp. Isolated from Ensiled Swamp Forage on Gastrointestinal Tract Development and Nutrient Digestibility in Native Ducks

The application of lactic acid bacteria (LAB), particularly Lactobacillus, as feed additives has demonstrated benefits for poultry, including enhanced gut function and better nutrient digestion. However, studies on LAB derived from swamp grass silage remain limited. The present study aimed to evaluate the effects of supplementing Lactobacillus spp. (Lacto) solution derived from ensiled swamp forage (Hymenachne acutigluma) at different concentrations through drinking water on the relative weight and length, as well as intestinal density and nutrient digestibility of native ducks. The relationship between intestinal tract density and nutrient digestibility was assessed using the Pearson correlation coefficient. The present study involved sixty 24-week-old native ducks, divided into five groups with four replicates each. The groups included a control group and groups that received Lacto solutions in their drinking water. The Lacto solutions were at concentrations of 1×106 CFU/mL (Lacto 1), 1×107 CFU/mL (Lacto 2), 1×108 CFU/mL (Lacto 3), and 1×109 CFU/mL (Lacto 4). The current results indicated that supplementation of the Lacto solution in drinking water increased the relative weights of the proventriculus, small intestine, duodenum, jejunum, ileum, and ceca. The relative weight and density of the intestine in the Lacto groups increased linearly with higher concentrations of Lacto solution. Compared to the control group, ducks receiving Lacto supplementation showed improved crude fiber digestibility (CFD) and a tendency to enhance organic matter digestibility (OMD). In 33-week-old ducks, a higher proventriculus density was associated with increased dry matter digestibility (DMD) and OMD. Additionally, the densities of the duodenum, jejunum, and ileum were positively correlated with DMD, OMD, and CFD. The present findings indicated that the administration of Lacto solution at increasing concentrations up to 109 CFU/mL via drinking water effectively improved the development of the small intestines of ducks, which was indicated by an increase in the intestinal relative weight and density, as well as enhancing the OMD and CFD in the diets.