The objective of the current study was to compare β-1,3-glucan, glycan-based precision biotic (PB), and Bacillus subtilis as alternatives to antibiotic growth promoters (AGPs) on gut morphology, nutrient utilization, blood biochemical parameters, and performance of broilers. For this purpose, a total of 500 one-day-old broiler chicks were randomly assigned to five experimental treatments, with 10 replicates of 10 birds each. Experimental birds were reared on a basal diet without AGP (CON) or the basal diet supplemented with AGP (100 g/ton), β-1,3-glucan (300 g/ton), a glycan-based PB (250 g/ton), and Bacillus subtilis (500 g/ton) in the diet. In the grower, finisher and overall phases, higher body weight, body weight gain and an improved (lower) FCR were observed in birds fed diet supplemented with PB (P<0.05). Similarly, the nutrient digestibility results showed that the highest digestibility was observed in birds fed a diet supplemented with PB (P<0.05). Moreover, the intestinal histology results showed that PB supplementation in diet increased villus height and goblet cell count in the jejunum and ileum (P<0.05). Similarly, PB dietary supplementation increased villus height, villus width, and crypt depth in duodenum (P<0.05). The results showed that supplementation with AGPs, and AGP alternatives positively influenced blood metabolites; total protein and albumin were highest in the PB group, while AST was lowest in the PB and β-1,3-glucan groups (P<0.05). Based on the results, it is concluded that AGP generally, while PB specifically, exhibited consistent positive responses on performance, nutrient digestibility, intestinal histology and blood biochemical indices in broilers.

To Cite This Article: Munawar H, Fatima A, Rehman MS, Basit A, Rahman MA and Bilal MQ, 2026. β-1,3-Glucan, precision biotic, and Bacillus subtilis as antibiotic growth promoter alternatives: effects on broiler performance, gut morphology, and serum biochemistry. Pak Vet J, 2026, 46(10): 2456-2465. http://dx.doi.org/10.29261/pakvetj/2026.233