A Bacillus-based synbiotic blend improves broiler productivity and metabolic resilience under suboptimal water...

Antibiotic growth promoters (AGPs) are being phased out in poultry production, leading to the search for functional non-nutritive additives. Synbiotic blends, such as the BBG complex, can enhance gut health and resilience against environmental stressors, particularly suboptimal water quality and heat stress.

This study aimed to evaluate the effect of a synbiotic blend (BBG) comprising Bacillus spp., β-glucans, and β-mannans as a non-nutritive immunostimulant on the productive performance and physiological parameters of broiler chickens.

A total of 264 one-day-old Ross broiler chickens were distributed into two treatments (n = 132 each) with three replicates of 44 birds each, covering three phases (pre-starter, starter, and finisher). The control group received a commercial diet, whereas the BBG group received a dietary inclusion (5%) of a conglomerate comprising Bacillus subtilis (10%-14%), Bacillus toyonensis (10%-14%), Bacillus licheniformis (13%-17%), Heyndrickxia coagulans (10%-14%), Shouchella clausii (13%-17%), β-glucans (1%-5%), β-mannans (1%-5%). Data were analyzed using one-way analysis of variance. Physicochemical analyses were performed on the feed and water, while production parameters (i.e., initial and final body weight (BW), daily feed intake, BW gain, feed conversion ratio, and mortality) were evaluated. Hematological and biochemical analyses were performed weekly.

Physicochemical analysis confirmed that the drinking water deviated from regulatory standards, exhibiting a lack of residual chlorine, slightly acidic pH, and elevated nitrate levels. BBG administration enhanced overall productive performance, yielding higher final BW and weight gain, alongside a noteworthy reduction in mortality during the pre-starter phase. Hematological analysis showed marked leukocytosis and elevated liver enzymes (alanine aminotransferase, aspartate aminotransferase, and bilirubin) in both treatments, confirming active environmental stress. Although BBG treatment did not completely normalize these stress indicators, it improved the birds´ resilience and enhanced feed efficiency during the initial stages.

The BBG synbiotic blend is a viable alternative to conventional AGPs, improving productivity and early viability under challenging field conditions characterized by high temperatures and suboptimal water quality.