Veterinární Medicína (Jan 2022)

Effect of Bacillus subtilis on the microarchitectural development of the immune system in Salmonella-challenged broiler chickens

  • A Sikandar,
  • H Zaneb,
  • A Nasir,
  • A Rehman,
  • M Kashif,
  • M Shah,
  • Z Luqman,
  • S Din,
  • Iqbal MF,
  • I Khan,
  • I Irshad

DOI
https://doi.org/10.17221/231/2020-VETMED
Journal volume & issue
Vol. 67, no. 1
pp. 28 – 37

Abstract

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The effect of Bacillus subtilis on the immune responses and morphometry of the immune organs was evaluated in broilers challenged with S. gallinarum. For this purpose, Salmonella-free birds (n = 240) were split into four groups with six replicates of ten birds each. Groups included an NC (negative control, non-infected + non-medicated), a PC-S (positive control, Salmonella-infected + non-medicated), an AT-S (Salmonella-infected + medicated with enrofloxacin), and a BS-S (Salmonella-infected + B. subtilis (2.0 × 1010 cfu/g; 0.1 g/kg) group. On day 21, the thickness of the thymus cortex and medulla, germinal centre area of the spleen, bursal follicular length and bursal follicular area increased (P < 0.05) in the BS-S when compared to the NC and PC-S groups. On day 35, the BS-S group exhibited a higher (P < 0.05) antibody titre against the Newcastle disease virus (NDV), and cortex of the thymus was thicker (P < 0.05) compared to the other groups. A decrease in the thymus medulla thickness, germinal area of the spleen and bursal follicular number were noted in the PC-S group when compared to the other treatment groups. In conclusion, the prophylactic use of B. subtilis type probiotics alleviated the stress resulting from a Salmonella gallinarum infection and improved the immune organs development and function in infected broilers.

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