Abstract: The primary objective of this study was to investigate the effects of feeding probiotic combination Fermented Soybean Meal (FSM) on performance, lipid metabolism and immunological response of growing-finishing pigs. Forty eight cross-bred pigs (TaoyuanxDuroc) were randomly allotted into three treatments, control, FSM-A and FSM-B treatment. The results demonstrated that pigs fed a diet with FSM-B showed a greater growth performance than control group. Compared with the control group, the cholesterol and triglycerides (TG) content in serum were reduced by fed pigs with FSM-A diet. Moreover, pigs had lower serum low density lipoprotein cholesterol (LDL-C) after fed with FSM diet. In immunological responses, the Classical Swine Fever (CSF) specific antibody titer was increased greater and faster by fed pigs with FSM. In conclusion, the dietary FSM supplementation had a beneficial effect on growth performance and immunological response of growing-finishing pigs. Nevertheless, these effects were also dependent on different probiotics combinations.
INTRODUCTION
Medical products such as antibiotics have been used successfully against diarrhea and have promoted growth performance; however, there is an increasing concern from both consumers and authorities on the health risks involved in consuming meat containing residues from feed additives, as well as the potential hazards from the spreading of resistance factors due to the indiscriminate use of antibiotics (Stein, 2002). Probiotics may be a substitute to replace antibiotics used exclusively as a growth stimulant in feed efficiency in farm animals. Probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host (Reid et al., 2003). Probiotic also appear in alimentary duct increase the immunological response (Klein et al., 2007) and reduce host cholesterol levels (Usman and Hosono, 2000). In addition, dietary supplementing with probiotic showed greater growth performance of pigs (Chen et al., 2006).
Fuller (1989) stated that using multi-strain microbial can be justified by the claim that it is acting in a broad spectrum and can be expected to be active in several different species of host animals. Although a large number of studies have been made on probiotic or relative fermented product, little is known about using soybean meal fermented by multi-strain bacterial combination for farm animals. Hence, this study was conducted to investigate the effects of soybean meal fermented by multi-strain microorganism on growth performance, serum lipid and the immune response of growing-finishing pigs.
MATERIALS AND METHODS
Animals and Diets
The experiment was carried out at Livestock Research Institute, Taiwan.
The experiment was a randomized complete block design. A total of 48 growing
finishing pigs were randomly allotted into three treatments according
pig`s gender. There were 2 pigs per replicate (pen) and 8 replicates per
treatment. Water and food were supplied ad libitum. Experimental
diet was formulated to meet the nutrient requirements of pigs according
to the National Research Council (1998). Pigs were fed a growing diet
from the first week to the 10th week (the average body weight approximately
from 30 to 80 kg) and were fed a finishing diet form 11th week to 20th
week (the average body weight approximately from 80 to 110 kg). The nutrients
composition of FSM and the formula of the diets are shown in (Table
1). Pigs were weighed biweekly during entire period. In addition to
this, pigs were vaccinated against CSF with 0.2 mL CSF vaccine (product
of Animal Health Research Institute, Taiwan) by i.m. injection on pig`s
weight around 90 kg.
Preparation of Fermented Soybean Meal
Microorganism cultures used in this study were obtained from the Food
Industry Research and Institute, Taiwan. The selections of microorganism
for this study were based on our pervious in vitro studies of their
probiotic properties. Fermented soybean meals were prepared as pervious
described with a slightly modify. Briefly, the cultures were transferred
into a premixed inoculated broth at 37°C for 12 h. Soybean meal was
sterilized by autoclave and cooled to room temperature for 1 h, then supplemented
with 17% premixed inoculated broth (3.2x109 colony forming
units (cfu) mL-1) and fermented in a closed 15 L plastic bucket
in temperature 32±2°C for 72 h. FSM-A was fermented by the
probiotic premixed inoculated broth A, including Streptococcus thermophilus,
Lactobacillus acidophilus, Aspergillus awamori, Bifidobacterium
thermophilum, Saccharomyces cerevisiae, Aspergillus niger
and Trichoderma koningi; FSM-B was fermented by the probiotic premixed
inoculated broth B, including Streptococcus thermophilus, Lactobacillus
acidophilus, Aspergillus awamori, Bifidobacterium thermophilum,
Saccharomyces cerevisiae, Corynebacterium acetoglutamicum,
Bacillus licheniformis and Aspergillus oryzae.
Table 1: | Ingredient and nutrient composition of experimental diets |
1Provided per kilogram of diet: Fe: 140 mg, Cu: 7 mg, Mn: 20 mg, Zn: 70 mg, I: 0.45 mg; 2Provided kg-1 of diet: Vitamin A: 6,000 IU, Vitamin D3: 800 IU, Vitamin B12: 0.02 mg, Vitamin E: 20 IU, Vitamin K3: 4 mg, Riboflavin: 4 mg, Pantothenic acid: 16 mg, Niacin: 30 mg, Pyridoxine: 1 mg, Folic acid: 0.5 mg, Biotin: 0.1 mg |
Analytical Procedures
Blood samples were collected before fed with experimental diet and
in 5th week for lipid metabolism study. At body weight approximately 90
kg, blood samples were collected from each pig before injected with CSF
vaccine and in the following three weeks for CSF antibody titer determination.
Cholesterol (Chol), high density lipoprotein cholesterol (HDL-C), LDL-C
and TG were measured by blood autoanalyzer (Trace Datapro
Plus, THERMO, Australia) and commercial kit (POINTE SCIENTIFIC, INC.).
CSF specific antibody titer was quantified utilizing a commercial ELISA
kit (BETHYL Laboratories INC. USA) and determined by ELISA reader (Thermo
Labsystems, Finland).
Statistical Analysis
Data were analyzed by ANOVA for a randomized complete block design
under the following model:
Yij = μ+Ti+Gj+Eij |
where, Yij is the dependent variable; μ is general mean; Ti is diet effect (i = 1-3); Gj is block by the gender of pigs (j = 1-2) and Eij is experimental error. The Tukey`s honest significant difference was used to test difference between treatment means. The statistical analysis was done using SAS program (SAS Institute Inc., USA). Differences among means with p<0.05 were accepted as representing statistically significant difference.
RESULTS AND DISCUSSION
Growth Performance
The growth performance of pigs fed FSM are presented in Table
2. Pigs fed with FSM-B significantly improved ADG throughout the experimental
period; moreover, pigs in FSM-A group had significantly higher ADG in
the first ten weeks (p<0.001). The FSM-B group also had higher ADFI
than control group in 10 to 20 weeks and overall period (p<0.05). Additionally,
the first ten weeks feed efficiency of FSM-B group was higher than the
control (p<0.05). These results were in agreement with other research
suggesting that probiotics have positive effect on the growth of growing-finishing
pigs (Shon et al., 2005). Nonetheless, their results were inconsistent
in our experiment; FSM-A was no significant difference compared with control
in ADFI and FE. As Shon et al. (2005) reported, fed microbial have
shown their greatest potential in very young and rapidly growing pigs
and no effects of growing-finishing pigs. In present study, the ability
of enhance growth performance were different between two FSM diets. The
effects may be diverse with fed different probiotic composition or species.
Lipid Metabolism
Results of porcine lipid metabolism at each group are presented in
Table 3. After five weeks feeding with FSM, pigs fed
with FSM-A diet significantly decreased porcine serum Cholesterol (p<0.01)
and TG (p<0.001). Furthermore, the FSM-A group showed a lower cholesterol
after treated with FSM for five weeks compared with two other groups (p<0.05).
Both FSM-A and FSM-B group had lower LDL-C than control group (p<0.001).
We are not clearly understood the actual mechanism of the probiotics combination
on lipid metabolism and the difference between two probiotics combination
diet. The possible reason is that the probiotic contain in FSM modulate
the symbiosis of gut microbial which may interact with host metabolism.
Martin et al. (2008) indicated that probiotic exposure exerted
microbiome modification and resulted in altered hepatic lipid metabolism
coupled with lowered plasma lipoprotein levels and apparent stimulated
glycolysis and altered a diverse range of pathways outcomes, including
amino-acid metabolism, methylamines and SCFAs.
Table 2: | Effect of dietary FSM supplementation on the growth performance of pigs |
a, bMeans within the same row with different superscripts different significantly (p<0.05), SEM: Standard Error of Means, N = 8 |
Table 3: | The effect of FSM on serum lipid concentration of pigs |
*Means with different superscripts in the same row differ significantly (p<0.05); **Means with different superscripts in the same row differ significantly (p<0.05); date were compared the difference of serum lipid content between basal status and after fed pigs with FSM, a, bMeans with different superscripts in the same column differ significantly (p<0.05); SEM: standard error of means; N = 8 |
Immunological Response
The trends of CSF specific antibody titer are shown in Fig.
1. After injected with CSF vaccine, the serum CSF titer of pigs at
both FSM-A and FSM-B showed an immediate sharp increase in the first two
weeks and then slightly raised from the second week to the third week.
By contrast, the line tendency of control group was increased slightly
in the first week. Notably, the second week CSF specific antibody titer
of FSM-A and FSM-B group were significantly higher than control group
(p<0.05). In porcine production, it is very important to improve immunity
in order to prevent infectious diseases. Utilization of immune-stimulants
is one solution to improve the immunity of pigs and to reduce their susceptibility
to infectious disease. Result from the current study revealed that after
vaccinated against CSF, both FSM-A and FSM-B showed immunestimulating
effect on increase serum CSF specific antibody titer of pigs. Lõpez
(2000) pointed out that probiotic could stimulate the humoral immune function
through increase in the concentration of IgG. In this study, pigs vaccinated
with CSF vaccine in order to understand the secondary immunological response
when pigs suffer an exogenous virus infection. Pigs fed with FSM diet
showed a faster and greater response after injected with CSF vaccine.
Therefore, probiotic combination fermented soybean meal may be a nutritional
immune-stimulant which provides a well protect on exogenous virus infection.
Fig. 1: | Profile of serum CSF antibody titer in pigs vaccinated against CSF vaccine. The date represent as mean. The CSF antibody titer in the second week was significantly higher in pigs fed with both FSM-A and FSM-B diet (p<0.05) |
CONCLUSION
The study implies that dietary supplementation with FSM fermented by probiotic combination to growing-finishing pigs enhanced ADG during the entire experimental period. Serum cholesterol and TG were reduced by the consumption of FSM. A greater secondary immune response also occurred in FSM group. These finding demonstrate that FSM is an effective carrier for probiotic as a functional feedstuff ingredient in pig production. Nevertheless, these effects were variable in the supplementation of different probiotic combination FSM.
ACKNOWLEDGMENTS
The authors wish to acknowledge Taiwan Livestock Research Institute staffs for animal care. The research project was fully supported by the National Science Council of Taiwan (NSC-93-3111-P-061-003-Y3).