Effects of fermentation products of Ganoderma lucidum on growth performance and immunocompetence in weanling pigs

In the current study, β-glucan present in fermentation products from Ganoderma lucidum (GLF) was tested as a feed supplement to evaluate its efficacy on growth performance and immunocompetence in weanling piglets suffering from physiological stress during weaning. This article focuses on after challenging with porcine circovirus (PCV) type 2, a supplementation with 50 mg GLF per kg feed also inhibited PCV-2 virus amplification,

Figure 1. Detection of PCV-2 nucleic acid in lymphoid tissue of weanling pigs after challenge with PCV-2 virus and feeding without or with fermentation products of Ganoderma lucidum (GLF) at 50 mg/kg for 4 weeks. M; 100 bp*1400 bp DNA marker; lane 1–3, spleen, inguinal and mandible lymph node without GLF; lane 4–6, spleen, inguinal and mandible lymph node with 50 mg GLF/kg.

In Figure 1, the results of a challenge experiment with PCV-2 via intranasal inoculation at a dosage of 105.2 TCID50 are shown. Two pigs in the challenge group (not GLF supplemented) showed obviously a respiratory syndrome and typical signs of hypersensitivity dermatitis, which were induced by viremia. By PCR the PCV-2 nucleic acid of the virus was detected in different lymphoid tissues including inguinal, mandible and spleen (Figure 1). Interestingly, no virus specific nucleic acid was detected in GLF groups and the histopathological examination showed only mild pathologic lesions. Moreover, in the control animal lymphocyte depletion, necrosis and haemorrhage in lymphoid tissues were observed in microscopic examination (data not shown). the results of the PCV-2 challenge experiment suggest that a potent antiviral activity may be due to the modulation of the cytokine profile and enhancing the virus elimination by the addition of GLF in feeds.

The results showed that at a supplementation level of 50 mg/kg feed, GLF caused the best growth performance (data not shown), after challenging with porcine circovirus (PCV) type 2, a supplementation with 50 mg GLF per kg feed also inhibited PCV-2 virus amplification, and ameliorated lymphocyte depletion in different lymphoid tissues. Conclusively, feed supplemented with GLF at 50 mg/kg could be beneficial to counteract the physiological stress in weanling piglets.