Effects of duo-strain probiotics on growth, digestion, and gut health in broiler chickens

Abstract

The goal of this inquiry was to analyze the impact of incorporating Enterococcus faecium and Streptococcus thermophilus using a novel premix-spray method on the following aspects: growth rate, digestive enzyme activity, antioxidant levels, gut microbiome composition, and the morphological characteristics of the duodenum, jejunum, and ileum in broiler chickens. Furthermore, this study explored the potential benefits of duo strains of probiotics (DSP) in reducing flatulence, regulating stool microbial population, and improving diarrhea symptoms. A total of 360 one-day-old mixed-sex Plymouth Rock chicks (IW: 51 ± 33 g) were randomly divided into two treatment groups. Each treatment group was further divided into 9 replicated cages, with 20 chicks housed in each cage. The control group (CG) received a basal diet composed of a soy-corn mixture, whereas the experimental group was provided with DSP (CON + 0.5 % probiotic). The results showed that the increase in the body weight of broilers at the end of the fourth week in the control group and the treatment group was 1.576 versus 1.847 kg, respectively. Throughout the 30-day trial period, the DSP diet significantly improved the specific growth rate (SGR), survival rate (SR), and body weight gain (BWG) while decreasing the feed conversion ratio (FCR) (P < 0.05). The DSP diet also enhanced the Enzymatic digestion (protease, amylase, lipase, and trypsin) and antioxidant potential (SOD, MDA, and catalase) of the broilers compared to those in the CG. The results revealed significant enhancements in the tissue morphology of the duodenum and jejunum following the combined treatment for a duration of 4 weeks. The DSP treatments significantly increased microvillus height in the duodenum and jejunum but had no notable effects in the ileum. Incorporating 0.5 % DSP in poultry feed improved the relative abundance of Ruminococcaceae and Faecalibacteriumin, leading to better management of diarrhea and reduced presence of E. coli compared to the control diet. Additionally, including probiotics in the basal diet reduced H₂S, CO₂, NH₃, and CH₄ levels. Overall, the study suggests that the new spray-drying approach with these strains has potential for supplementing probiotics in poultry feed processing, and including DSP in broiler chicken diets has beneficial effects.

Keywords: Antioxidant levels; Broiler; Duo-strain probiotics; Enzymatic digestion; Growth rate; Gut Microbiome.

Fig. 1

The impact of temperature change on DSP strain prior to spraying was investigated. The following were evaluated: (A) Combination of S. thermophilus and E. faecium strains at 30 °C, where microorganism growth is inactive at or below 30 °C. Meanwhile, (B) and (C) bacterial growth on MRS and TSB medium, respectively, were assessed at 37 °C and pH levels ranging from 6.5 to 7.

Fig. 2

The impact of concentration, pH level, and temperature operational variables on the growth rate of the DSP complement within a 48-hour timeframe. (A). The effect of variations in temperature and the specific characteristics of the culture medium (whether it is basic, acidic, or neutral) on the rate of growth of the DSP strain composition. (B) The effect of optimal concentration of DSP and the effectiveness of strain in protecting the survival of probiotic during the culture period.

Fig. 3

The effectiveness of the dietary DSP when stored at room temperature (27 ± 2 °C). The reported values represent the average ± standard deviation of log colony-forming units per gram for three independent trials.

Fig. 4

The impact of dry-spraying dietary DSP on the antioxidant capacity of broilers was assessed. The mean ± standard deviation values for the following antioxidant enzymes: MAD, CAT, ROS, PCO, TAC, SOD, CAT, and GPx, were determined for nine independent trials. All values were measured in units per milligram of protein (U/mg protein).

Fig. 5

Impact of dietary E. faecium and S. thermophilus on the activity of digestive enzymes in broilers was evaluated. The mean ± standard deviation values for (A) amylase, (B) lipase, (C) protease, and (D) trypsin were determined for nine independent trials, and significant differences (p < 0.05) between groups were indicated by different letters.

Fig. 6

Effects of Enterococcus faecium, and Streptococcus thermophilus on the intestinal morphology of broilers fed diets supplementation, 60Co γ-ray. Control, birds fed with basal diet; DSP, 110 mg/kg DSP. (A) day, 7, (B) day 14, (B) day 21, (C) day 30.

Fig. 7

The impact of dietary supplementation with DSP on the cecal microbiota composition of broiler chickens was examined on day 31, focusing on the phylum, family, and genus levels. Microbiota composition at these levels was denoted as (A, B, C) respectively. Statistical analysis revealed a significant difference at P ≤ 0.05.

Fig. 8

The impact of dietary DSP on the diversity of intestinal microflora in broilers was examined through assessment of both α and β diversity. Alpha diversity was measured using four indices: (A) Chao1, (B) Shannon, (C) Goods coverage, and (D) Simpson, while (E) β diversity was analyzed utilizing PCoA.