Effect of Solid-State Fermentation Products of Lactobacillus plantarum, Candida utilis, and Bacillus coagulans on Growth Performance of Broilers and Prevention of Avian Colibacillosis

Abstract

This study investigates the impact of the solid-state fermentation products of Lactobacillus plantarum, Candida utilis, and Bacillus coagulans (LCBs) on the growth characteristics, immune function, intestinal morphology, cecum microbial community, and prevention of avian colibacillosis in broilers. One hundred and twenty Hyland Brown broilers (aged one day) were divided randomly into three groups (four replicates of ten broilers per group). (1) The CON group was fed a basal diet. (2) The MOD group was fed a basal diet. On day 40, APEC strain SX02 (1.1 × 10⁵ CFU/g) was administered to the breasts of chickens in this group. (3) The LCBs group was fed a basal diet supplemented with fermentation products (98.5% basal diet + 0.5% Lactobacillus plantarum and Candida utilis solid-state fermentation products + 1.0% Bacillus coagulans solid-state fermentation products). On day 40, the LCBs group received the same treatment as the MOD group. The experiment lasted 43 days. This study found that the average daily gain (ADG) of the LCBs group was significantly higher than that of the MOD group (p < 0.05), indicating that LCBs can significantly increase the ADG of broilers and improve the feed conversion ratio. Furthermore, compared to the MOD group, the heart bacterial load was significantly reduced in the LCBs group (p < 0.05), and the lesions less severe in the heart, liver, and jejunum were observed (p < 0.05). Additionally, the detection of intestinal flora showed a significant increase in the abundance of beneficial bacteria in the cecum of the LCBs group, while the number of Escherichia coli and Shigella decreased significantly. In conclusion, the solid fermentation of Lactobacillus plantarum, Candida utilis, and Bacillus coagulans can improve the growth performance of broilers while also protecting against avian pathogenic Escherichia coli infection. This demonstrates the potential usefulness of these LCBs in feed production.

Keywords: Bacillus coagulans; Candida utilis; Lactobacillus plantarum; avian pathogenic Escherichia coli.

Figure 1

The animal experiment schematic diagram.

Figure 2

Growth performance. (a) The average daily feed intake of broilers from one to forty-three days of age. (b) The average daily gain of broilers from one to forty-three days of age. Data were analyzed using SPSS 22.0 ANOVA and the differences were compared using SPSS 22.0 Duncan’s multiple range test to the significance levels of 5% and 1%. Diverse lowercase letters show significant differences (p < 0.05), diverse capital letters show significant differences (p < 0.01). (c) The survival rate of broilers after APEC SX02 infection.

Figure 3

Microscopic lesions of the (a) CON heart, (b) MOD heart, (c) LCBs heart, (d) CON liver, (e) MOD liver, (f) LCBs liver, (g) CON jejunum, (h) MOD jejunum, and (i) LCBs jejunum were observed 3 days after APEC SX02 infection. The red arrows indicate macroscopic lesions of the heart, liver, and jejunum, with congestion, edema and hemorrhage.

Figure 4

Tissue lesions of the heart, liver, and jejunum. Tissue morphology of (a–c) CON heart, MOD heart, and LCBs heart, (d–f) CON liver, MOD liver, and LCBs liver, and (g–i) CON jejunum, MOD jejunum, and LCBs jejunum, respectively. The red arrows indicate a change in the tissue histomorphology of the heart, liver, and jejunum

Figure 5

Bacterial load of heart, liver, and lung in CON, MOD, and LCBs groups. (Error bars are the mean ± SD, ** p < 0.01, ns means no significant difference, n = 3.)

Figure 6

(a) Simpson index and (b) Shannon index of broilers after APEC SX02 infection. The composition of the intestinal flora at the (c) species and (d) family levels.