Jd. Kim et al., Effects of immunostimulators on growth performance and immune response in pigs weaned at 21 days of age, J ANIM FEED, 9(2), 2000, pp. 333-346
One hundred and fifty pigs with an average body weight of 6.6 kg were allot
ted to treatment in a completely randomized block design. The treatments in
cluded: 1. Control (basal diet), 2. P-glycan (basal diet + 40 ppm peptidogl
ycan), 3. MOS (basal diet + 0.1% mannanoligosaccharides), 4. MG (basal diet
+ 0.4% beta-glucan) and 5. NIS (basal diet + 300 ppm Nonspecific Immunosti
mulating Anionic Alkali Solution, rice bran was used as a carrier). Each tr
eatment had 6 replicates with 5 pigs per replicate. Overall, although there
were no significant differences in animal performance, pigs fed MOS showed
better growth performance and feed efficiency than the other groups. Nutri
ents and amino acid digestibilities were improved during phase II (d 15 to
28 post-weaning) compared to phase I (d 0 to 14 post-weaning). During the e
ntire experimental period, pigs fed control and other experimental diets in
creased T cytotoxic and suppressor cells (CD8+), which contrasted with the
decline in T helper cells (CD4+) and granulocyte and monocyte proportions i
n week 3 after feeding (d 21) compared to week 1 after feeding (d 7). The d
ecrease of T helper cells, granulocytes and monocytes between weeks 1 and 3
was higher in pigs fed diets supplemented with P-glycan, MOS, MG and NIS t
han in pigs fed the control diet. From d 15 to 28 post-weaning, the diarrho
ea score was lower in pigs fed diets supplemented with any of the immunosti
mulators compared to phase I (d 0 to 14 after weaning), except for the NIS
treatment. The diarrhoea symptom showed the largest improvement in the MOS
group, but there was no statistically significant difference among all of t
he treatments. In conclusion, these data suggest that the inclusion of immu
nostimulators (peptidoglycan, mannanoligosaccharides, beta-glucan and NIS)
has no beneficial effect on growth performance, except for mannanoligosacch
arides. But the use of some immunostimulators showed a potential for weaned
pigs to increase body growth (mannanoligosaccharides), return quickly to a
low-key immune system (mannaolisosaccharides, beta-glucan and NIS), reduce
mortality (beta-glucan) and diarrhoea (mannanoligosaccharides).