Influence of lactulose as a composition of organic-mineral feed additive on broiler chicken productivity, feed digestibility, and microbiome

Background and Aim: The global demand for efficient poultry production necessitates alternatives to antibiotic growth promoters. This study aimed to evaluate the effects of a novel four-component organic-mineral feed additive (OMFA), comprising lactulose, arginine, ultrafine silicon dioxide particles, and succinic acid, and a three-component variant (without lactulose) on growth performance, nutrient digestibility, elemental tissue composition, and the cecal microbiota of Arbor Acres broiler chickens. Materials and Methods: One hundred and five one-day-old broiler chicks were randomly allocated into three groups: Control, Group I (four-component OMFA), and Group II (three-component OMFA). Growth metrics were recorded weekly over a 42-day period. Nutrient digestibility was assessed through balance experiments, while elemental tissue composition was measured by inductively coupled plasma mass spectrometry. Cecal microbiota profiling was conducted using 16S ribosomal RNA gene sequencing on the MiSeq platform. Statistical analyses were performed using the Mann-Whitney U-test. Results: Group I showed an 11.2% increase in body weight gain and a 9.6% reduction in feed conversion ratio compared to controls (p = 0.074; p = 0.063). Group II demonstrated superior weight gain (17.9%) but incurred a 3.6% increase in feed costs. Digestibility of crude fat and protein improved significantly in Group II (p = 0.037). Elemental analysis indicated that lactulose supplementation enhanced the accumulation of magnesium, calcium, manganese, cobalt, zinc, and chromium in muscle tissue. Microbiota analysis revealed that Group I increased Ruminococcaceae abundance and suppressed Pseudobdellovibrionaceae, while Group II favored the proliferation of Helicobacteraceae, Rikenellaceae, and Bacteroidaceae. Conclusion: Both OMFA formulations enhanced productivity and modulated gut microbiota. The four-component OMFA improved feed efficiency and mineral deposition, while the three-component version elicited greater weight gains. These findings support the incorporation of OMFA as a strategic tool in antibiotic-free poultry production. Further studies are warranted to elucidate the metabolic interactions among additive components and their long-term effects on gut health and performance.