Ganoderma lucidum (GL) is a mushroom that has been widely used in Asia for its immunostimulatory and anti-inflammatory capacity, which has been hypothesized to be attributed mainly to the recognition of its cell-surface patterns by cells of the immune system present in the gastrointestinal tract, resulting in a cascade of modulatory events. However, the nutraceutical properties of GL have not been tested in dogs. Forty adult beagles were used in a completely randomized design. The objective of the present study was to evaluate the effects of dietary inclusion of GL on peripheral blood mononuclear cells (PBMC; T cells, B cells, monocytes, and natural killers), vaccine response, nutrient digestibility, fecal fermentative end-products, and skin and coat quality of adult dogs. Dogs were fed a commercial dry extruded complete and balanced diet plus GL top-dressed daily upon feeding time. Four experimental treatments were used: 0% GL supplementation (control), 5 mg/kg BW of GL, 10 mg/kg BW of GL, or 15 mg/kg BW of GL. Following a 7 d adaptation to the control diet, dogs were fed their respective treatment diets for 28 d. They were challenged with vaccination of a modified live virus Canine Distemper, Adenovirus Type 1 (Hepatitis), Adenovirus Type 2, Parainfluenza, and Parvovirus and killed Rabies Virus on day 7 with blood collections on days 0, 14, and 28. The inclusion of GL in all dosages was well-accepted by all dogs, with no detrimental effect on macronutrient apparent total tract digestibility. There was a trend that the percentage of major histocompatibility II (MHC-II) from B cells was greater in dogs fed 15 mg/kg of GL (41.91%) compared to the control group (34.63%). The phagocytosis response tended to have treatment-by-time interaction among treatments; dogs fed 15 mg/kg of GL tended to have greater phagocytosis activity on day 28 than dogs from the control group and dogs fed 5 mg/kg of GL. The vaccine-specific serum immunoglobulin G (IgG) concentrations were higher in the group supplemented with 15 mg/kg of GL compared to treatment control 7 d after the vaccination for rabies. These data suggest that the inclusion of GL had no detrimental effects on any analyzed PBMC. Due to changes in immune parameters among treatments, GL may also exert beneficial immunostimulatory effects in healthy adult dogs when provided at a daily dose of 15 mg/ kg BW.
Keywords: Ganoderma lucidum; canine; immune; vaccine response.
Ganoderma lucidum (GL) is a fungus from which products have become popular in the human food and health industry over the past decade. Due to this, a growing interest in using GL extracts in animal products has also developed. The current study investigated the nutritional properties of GL supplemented to adult beagles in three different inclusion levels in terms of body weight (BW; 5, 10, and 15 mg/kg BW). The results indicated no impact on the overall health, apparent total tract macronutrient digestibility (ATTD), fecal microbial DNA, and skin and coat health. The highlighted results included increased phagocytic activity and vaccine-specific response in the group of dogs supplemented with 15 mg/kg BW.
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