Abstract:
Presently, because of the increasing use of antimicrobial drugs in the pig industry,
drug residues have begun to affect human health more and more. The use of natural
products for animal immunomodulation may minimize this problem. This study was
performed in nursery pigs to study the effects of probiotic herbal solution on growth
performance (average weight daily gain (ADG), feed intake (FI) and feed conversion ratio
(FCR)), morbidity rate, frequency of antimicrobial usage, hematology and immune cells
(lymphocyte subsets and monocytes by flow cytometry, including percentage of CD3+,
CD3+CD4+ and CD3+CD8+ lymphocytes, CD4+/CD8+and SWC3a+Monocytes).
Thirty clinically healthy weaning pigs with a body weight of 8.5 ± 0.4 kg,
and 21-28 days of age, were divided into 5 groups, with 6 pigs in each group. Group 1
received placebo; group 2 received sugar cane solution; group 3 received fermented
sugar cane solution; group 4 received sugar cane plus powder herb solution; and group
5 received fermented sugar cane plus powder herb solution (probiotic herbal solution).
All groups received the preparation at 7.00 a.m., once every morning for 41 days.
Body weights were recorded before the experiment (day 0) and each week of the
experiment. Blood was collected at days 0, 14 and 35 for hematology and immune
cells analysis. Feed intakes and morbidity were observed and recorded every day.
Furthermore, the level of lactic acid bacteria in the preparations was determined.
There were no significant differences in ADG, FI, FCR, morbidity rate and
antimicrobial drug usage among groups. Hematology parameters were not significantly
different (p-value > 0.05) among groups except for the platelet counts and numbers of
monocytes. Furthermore, leukocytosis and lymphocytosis were presented in all groups. At
day 35, percentages of CD3+ and CD8+ T-cell lymphocytes in all groups were higher but
percentages of CD4+ T-cell lymphocytes in all groups were lower, compared with day 0,
subsequently, CD4+/CD8+ ratios were very low. This indicated that cytotoxic T-cell
lymphocytes were stimulated more than helper T-cell lymphocytes. This may be a result of
immune response against swine fever vaccine or virus infection. At day 35, the percentages
of SWC3a+Monocytes of all groups were lower, compared with day 0. This may be because
peripheral blood monocytes changed to tissue macrophage for non-specific immune
response. Lactic acid bacterial counts were much lower than the recommended dose.
These findings suggest that the probiotic herbal solution may not be useful as an
immunomodulator for nursery pigs in the field because it did not minimize morbidity rate
and antimicrobial drug usage.