Tri-strain probiotics improves performance, excreta microbial shedding and reduces noxious gas emission in broilers

Abstract Text: This study was conducted to evaluate the effects of Bacillus subtilis, Clostridium butyricum and Lactobacillus acidophilus (tri -strain probiotics, TSP) endospores in broilers. The TSP can benefit the host animal by increasing the nutrients absorption from the gastrointestinal tract and altering the intestinal ecosystem in the poultry. A total of 500 day old ROSS 308 mixed sex broiler chickens with an average initial body weight (IBW) of 46g ± 0.5g were used in this 35-d feeding study. Broiler chickens were randomly allotted to 1 of 5 dietary treatments: 1) CON (antibiotic free diet), 2) ANT1 (CON + enramycin 5 ppm), 3) ANT2 (CON + avilamycin 5 ppm), 4) TSP1 (CON + 0.1% TSP) and 5) TSP2 (CON + 0.2% TSP) with 5 replications per treatment and 20 chicks per pen. Ileal and caecal contents were collected into Qorpak glass containers (118 mL) under CO₂ for enumeration of microbial populations. Data were statistically analyzed via ANOVA using the GLM procedure of SAS/STAT^®9.2 (SAS Institute 2008). The linear and quadratic effects of TSP among treatments were analyzed using a contrast statement. Orthogonal contrasts were used to the effects of treatments: ANT vs. TSP treatments. Broiler chickens fed on TSP1 and TSP2 diets linearly increased body weight gain (BWG) and decreased feed conversion ratio (FCR) than those on the CON diet (9,19, 9,55 vs. 8,86 g/chick; 1.828, 1.822 vs. 1.937, and 1,945, 1,965 vs. 1766 g/chick; 1.596, 1.600 vs. 1.655; P < 0.05; d 21 to 35 and d 1 to 35, respectively). The dry matter (DM) and nitrogen (N) digestibility were linearly improved in the TSP1 and TSP2 treatments compared with the CON treatment at the end of study (77.43, 77.22 vs. 70.48%, and 69.49, 71.93 vs. 68.43%; P < 0.05). The inclusion of TSP1 and TSP2 treatments reduced meat lightness (L*) compared with CON and ANT1 and ANT2 treatments (linear, 51.2, 51.8 vs. 56.2, 53.2, 55.4; P = 0.02).  The supplementation of TSP1 and TSP2 increased ileal and caecal Lactobacillus count (^log₁₀ cfu/g) compared with CON and ANT1 and ANT2 diets (8.83, 8.91 vs. 8.55, 8.65 and 8.62, and 9.71, 9.76 vs. 9.03, 9.47 and 9.25; P < 0.05). Excreta ammonia (NH₃) gas emission was lower in the TSP1 and TSP2 treatments compared with CON treatment (74, 70 vs. 80 ppm; P < 0.05) on d 5. In conclusion, the supplementation of TSP improved growth performance, nutrient digestibility, meat quality, ileal and caecal Lactobacillus count, and reduced noxious gas emission in broilers.

Keywords: ammonia gas emission, scherichia coli, eat lightness