Effects of bamboo charcoal on the growth performance, blood characteristics and noxious gas emission in fattening pigs

Abstract

This study was carried out to investigate the effects of bamboo charcoal on the growth performance, immune responses of blood, faecal gas emission and faecal microflora in fattening pigs. Crossed pigs (n =1 08) were fed basal diet (C) and supplemented with 0.3% (T1) and 0.6% (T2) of bamboo charcoal for 42 days (12 heads per pen×3 diets×3 replications). The average daily gain (ADG) and feed efficiency were higher (P < 0.05) in T1 and T2 than in C. The concentration of lactate dehydrogenase (LDH), triglyceride and blood urea nitrogen (BUN) as well as faecal gas emission, such as ammonia, methane, amine and hydrogen sulphide were lower (P < 0.05) in T2, while the concentration of cortisol and counts of faecal enterobacteriaceae, Escherichia coli and Salmonella spp. were lower (P<0.05) in T1 and T2 compared with the C. Concentration of IgG and count of faecal Lactobacillus spp. were higher (P<0.05) in treatments. Based on these results, bamboo charcoal increased the growth performance, feed efficiency and faecal beneficial microflora composition, but decreased the faecal noxious gas emission in fattening pigs.

Keywords:

• bamboo charcoal
• blood characteristics
• growth performance
• noxious gas emission
• pigs

1. Introduction

Charcoal has been used in medicine for the past 100 years due to its ability to adsorb most poisons (Chyka and Seger 2005). In the mid-1970s, activated charcoal was accepted as an antidote in adsorption and elimination of a variety of medications (Davies 1991). Charcoal generally refers to the carbonaceous residue of wood, coconut shells and various industrial wastes left after heating organic matter in the absence of oxygen. Charcoal is an adsorbent for many toxins, gases, drugs, fat and fat-soluble substances without any specific action (Kutlu et al. 2001). The adsorptive power of charcoal could be increased considerably by treating with various substances at temperatures ranging from 500 to 900°C. The final product is called activated charcoal (Osol 1975). Activated charcoal is a fine black powder that is produced from the decomposed material of various organic materials, which is then exposed to oxidising gases at high temperatures to activate and increase the surface area (Clegg and Hope 1999). Activated charcoal has been shown to adsorb a wide range of compounds (Struhsaker et al. 1997). Adsorption therapy with activated charcoal as a non-digestible carrier is one of the important methods of preventing the ingested toxicants or noxious substances formed in the gastrointestinal tract (McLennan and Amos 1989; McKenzie 1991; Jindal et al. 1994). The extreme inertness of charcoal makes it an unlikely source of minerals when passed through the mammalian digestive system (Cooney 1995). Activated charcoal controls the lactic acid concentration by maintain pH level and microflora population in rumen (Hoshi et al. 1991). It also combines with the phenol in gastrointestinal tracks, which prevent interference of hydrosoluble tannins with enzyme's function and protein digestion (Murdiati et al. 1991).

Bamboo charcoal is an activated charcoal made by dry distillation and powder of thick-stemmed bamboo, which contain a complex network of pores of various shape and size and can bind a variety of molecules (Zhao et al. 2008). It is considered to have a higher adsorption capacity because of the special structure of micro-pores found in bamboo stem (ChungPin et al. 2004). Bamboo charcoal powder is an insoluble carrier that non-specifically adsorbs molecules and prevents their absorption, therefore, it has been used as an oral antidote to reduce absorption of poisons from the gastrointestinal tract (Anjaneyulu et al. 1993). Hence, this experiment was carried out to investigate bamboo charcoal as an animal feed additive.

Some researchers studied charcoal and activated charcoal as animal feed additive. Charcoal affected growth performance and carcass traits in fattening pigs (Hwang 1995), and was used as feed additive for production of high-quality meat (Kim 1990). Activated charcoal also affected microbes reproduction in sheep (Knutson et al. 2006) and meat quality and storage characteristics of pork (Lee et al. 2011). However, to our knowledge, dietary of bamboo charcoal has not been studied in pigs and this study focused on it as a feed additive for pigs. Moreover, the main purpose of this study was to investigate whether the growth performance, blood characteristics, immune response, noxious gas emission and faecal microflora population of fattening pigs fed dietary bamboo charcoal could be improved.

2. Materials and methods

2.1. Preparation of bamboo charcoal

The detailed process of activated bamboo charcoal was divided into three steps: (1) bamboo (Phyllostachys pubescens) chips of 1 cm (width)×2 cm (length) were heated at 700°C for 6 hours and cooled to room temperature (RT) to produce ashed bamboo, (2) the ashed bamboo was transferred to a rotary furnace and heated at 900°C for 8 hours and cooled to RT to form activated charcoal and (3) the activated bamboo charcoal was ground to less than 200 by jet mill and mesh (less than 100 µm diameter).

2.2. Animals

Experimental pigs were at the age of approximately 140 days and an average body weight (BW) of 79.0±2.2 kg at the initiation. Pigs (n=108) were assigned to three dietary treatments based on BW and sex, and each treatment contained 12 pigs per pen in three replicates (12 pigs×3 diets×3 replications). They were given pre-feeding for 3 days, had free access to water and experimental diet until 113.3±1.9 kg of BW. The Guide for the Care and Use of Laboratory Animals (Animal Care Committee of Gyeongnam National University of Science and Technology) was followed in this study.

2.3. Diet

Basal diet was made of approximately 51.80% corn, 14.59% wheat and 11.12% soybean meal (Table 1). Chemically, the basal diet consisted of 14.00% crude protein, 3.125 Mcal/kg metabolism energy (ME), 0.80% lysine and 0.40% total phosphorus. The control pigs were fed basal diet (C), while basal diet supplemented with 0.3% (T1) and 0.6% (T2) of bamboo charcoal were the treatments. The duration of experimental diet was 42 days.

Table 1. Constituents of experimental diet.

Parameters	Composition
Ingredients, as-fed basis (%)
Corn	51.80
Wheat	14.59
Soybean meal	11.12
Dried distiller's grains with soluble	7.00
Rice bran	4.81
Molasses	3.38
Rapeseed meal	3.00
Limestone	1.16
Gluten feed	1.00
Animal fat	1.48
Salt	0.33
Lysine	0.21
Vitamin premix^1	0.07
Trace mineral premix^2	0.05
Chemical composition, ^3 as-fed basis (%)
Crude protein	14.00
Metabolism energy (Mcal/kg)	3.125
Lysine	0.80
Calcium	0.70
Total phosphorus	0.40
^1Supplied per kilogram of diet: 8000 IU vitamin A, 4000 IU vitamin D, 1500 IU vitamin E, 150 mg vitamin K, 20 mg vitamin B12, 20 mg niacin, 10 mg thiamin, 20 mg pantothenic acid, 4.0 mg riboflavin, 0.6 mg folic acid and 0.03 mg Biotin, 30 ppm.
^2Supplied per kilogram of diet: 60 mg Zn, 60 mg Fe, 25 mg Mn, 15 mg Cu, 0.25 mg Se and 0.20 mg I.
^3Calculated value.

2.4. Growth performance and blood analyses

The BW was measured at the start and end of this experiment. Consumption amounts of diet were recorded everyday at feeding time. The feed efficiency was calculated based on average daily gain (ADG) and feed intake.

Three hours after the last feed, blood samples were randomly collected from the jugular veins of 12 pigs (four pigs per pen) from each treatment. Blood corpuscles mainly leucocytes, erythrocytes, haemoglobin, haematocrit and platelets were determined within 2 hours of blood sampling using an automatic haematological analyser (VET abc, Montpellier, France). The plasma was obtained by centrifugation of blood at 2500×g for 30 min at 4°C and stored at −20°C for further chemical analysis. The concentration of total protein, albumin, lactate dehydrogenase (LDH), total cholesterol, triglyceride, blood urea nitrogen (BUN), high-density lipoprotein (HDL)-cholesterol and low-density lipoprotein (LDL)-cholesterol were obtained using Blood Analyzer (Express Plus, Bayer, MA, USA). Cortisol concentration was measured using an Immulite (Diagnostic product Co., USA) method for chemiluminescent immunoassay.

2.5. Detection of antibodies

Total porcine immunoglobulin was determined in serum as previously described by Mizumachi et al. (2009). Blood samples were collected in heparinized vacutainer tube (Becton Dickinson, San Jose, CA, USA) then centrifuged at 10,000×g for 2 min after clotting and stored individually at −80°C. Total porcine immunoglobulin M (IgM), immunoglobulin G (IgG) and immunoglobulin A (IgA) antibodies were measured by a sandwich enzyme-linked immunosorbent assay (ELISA). For the detection of IgM, IgG and IgA, microtiter plate wells (Maxisorp; Nunc, Roskilde, Denmark) were coated overnight at 4°C with goat anti-porcine IgM, IgG or IgA (Bethyl Laboratories, Montgomery, TX, USA). The coated wells were washed with phosphate buffer saline (PBS) containing 0.05% (w/v) Tween 20 (PBST), and blocked with 1% (w/v) bovine serum albumin (BSA) in PBS for 30 min. After washing with PBST, the approximately diluted samples were added and incubated for 2 hours at RT. Then the wells were treated with horseradish peroxidase-conjugated goat anti-porcine IgM, IgG or IgA (Bethyl Laboratories) for an hour at RT. The wells were washed and 3,3′,5,5′-tetramethylbenzidine (TMB) solution (KPL, Gaithersburg, MD, USA) was added to each well as a substrate. After 30 min of incubation, the reaction was stopped by the addition of 1 M dihydrogen phosphate (H₂PO₃). Absorbance was measured at 450 nm in a microplate reader (Original multi scan, Thermo, USA).

2.6. Determination of faecal pH and noxious gas emission

Faeces of 12 randomly selected pigs in each treatment (four pigs per pen) were collected at the end of experiment for analysis of pH, noxious gas emission (ammonia, amines and hydrogen sulphides) and faecal volatile fatty acid (VFA) concentration. The collected samples of faeces were transferred in tightly closed plastic containers.

Values of faecal pH were measured using a pH meter (Hanna HI 9025, Woonsocket, RI, USA) with an Orion 8163 glass electrode (Beverley, MA, USA).

Concentration of ammonia and methane gas was measured in faeces as previously described by Chaney and Marbach (1962). For the detection of ammonia gas, 0.06 mL mercury chloride was added to 6.2 mL faecal extract to suppress microbial activity then centrifuged at 3000×g for 15 min. A sample of 0.02 mL supernatant and 0.2 mL standard solution was mixed with 1 mL phenol colour and 1 mL alkali-hypochlorite reagent, incubated at 50°C for 7 min then 8 mL distilled water (DW) were added. Absorbance was measured at 630 nm in a spectrophotometer (Model 680, Bio-Rad, USA).

For detection of methane gas emission, 5 g fresh faecal samples were incubated at 35°C for 30 min and the gas was collected in a sealed tube. The methane gas was measured in a gas chromatograph (GC-2010, Shimadzu, Japan). Gas samples were injected twice into the gas liquid chromatography (GLC) column and performed on a Porapak N + Q capillary GLC column (2 m×05.3 mm i.d.; 1.50 mm film thickness; Agilent HP, USA) with helium as a carrier gas. The mass spectrometry interface and injector temperature were fixed at 110 and 80°C, respectively.

Amine and hydrogen sulphide gas emissions were measured in Gastec (GV-100, Japan).

The VFA concentration was determined by the method of Erwin et al. (1961). DW of 90 mL were added to 10 g fresh faecal samples then homogenised for 1 min and centrifuged at 3000×g for 3 min. A supernatant of 1 mL was transferred and mixed with 0.2 mL of 25% (w/v) metaphosphoric acid and let stand at RT for 30 min. The supernatant was collected and filtered using a syringe filter (pore size; 0.20 µm). Finally, the VFA concentration in the supernatant liquid was determined in a high-performance liquid chromatography (HPLC; Agilent 1200, Agilent, Germany). Samples of 10 µL were injected twice into the HPLC column and performed on a MetaCarb 87H column (3 m×7.80 mm i.d.; 1.50 mm film thickness; Agilent HP, USA) with a flow rate at 0.7 mL per min carrier solution was 0.015 N sulphuric acid at 210 nm of wavelength of detector (L-2490, Hitachi, Japan) was 210 nm.

2.7. Microbial analyses

Ten grams of fresh faeces were collected from 12 randomly selected pigs in each treatment (four pigs per pen) at the end of experiment for analysis of faecal microflora. Samples were mixed with 90 mL DW and homogenised at 2500×g for a min. The homogenised samples were diluted between 10⁻³ and 10⁻⁸ folds. Anaerobic total bacteria incubated on Nutrients agar (Cat. No. 213000; Difco, NJ, USA) at 37°C for 48 hours under anaerobic conditions. Lactobacillus spp. was grown on Man Rogosa Sharpe (MRS) agar (Cat. No. 288210; Difco) at 35°C for 72 hours under anaerobic conditions, while Escherichia coli and Salmonella spp. were grown on MacConkey agar (Cat. No. 212123; Difco) and Salmonella-Shigella (SS) agar (Cat. No. 274500; Difco) at 37°C for 24 hours under aerobic conditions, respectively. Colonies on each plate were counted on a colony counter (Suntex-570, Sung Kwang, Korea). Colony forming units (cfu) were defined as being distinct colonies if they measured less than 1 mm in diameter.

2.7. Statistical analyses

The data were analysed based on the General Linear Model (GLM) procedures of SAS (1999) and significant differences among the means were calculated by the Duncan's Multiple Range Test method (Duncan 1955). P-value less than 0.05 were considered significant.

3. Results

The bamboo charcoal affected the growth performance and feed efficiency of fattening pigs (Table 2). The final BW, ADG and feed efficiency were significantly higher (P<0.05) in T1 and T2 than in C, and were not different between T1 and T2.

Table 2. The effects of bamboo charcoal on growth performance and feed efficiency in fattening pigs.¹

	Treatment^2
Parameters	C	T1	T2	Standard error mean (SEM)
Growth performance
Initial body weight (kg)	78.17	80.00	79.00	2.18
Final body weight (kg)	109.67^b	116.83^a	113.33^a	1.87
Average daily gain (kg/day)	0.750^b	0.877^a	0.817^a	0.064
Feed intake
Average daily feed intake (kg/day)	2.62	2.61	2.52	0.12
Feed efficiency (g/g)	0.286^b	0.336^a	0.324^a	0.031
^1Mean of 36 pigs individually housed in each treatment.
^2The basal diet was supplemented with bamboo charcoal: C, no supplement; T1, 0.3% and T2, 0.6%.
^a,bValues in the same row with different superscripts differ at P < 0.05.

Bamboo charcoal showed no effect on the concentration of leucocytes, erythrocytes, haemoglobin, haematocrit and platelets in blood corpuscles, but significantly affected (P<0.05) the concentration of total protein, albumin, total cholesterol, HDL-cholesterol and LDL-cholesterol of the plasma. The concentrations of LDH, triglyceride and BUN were significantly lower (P<0.05) in T2 and the cortisol concentration was significantly lower (P<0.05) in both treatments (Table 3).

Table 3. The effects of bamboo charcoal on blood corpuscles and chemical composition of plasma in fattening pigs.¹

	Treatment^2
Parameters	C	T1	T2	Standard error mean (SEM)
Blood corpuscles
Leucocytes (10^3/mm^3)	20.28	24.80	24.88	1.32
Erythrocytes (10^6/mm^3)	8.29	8.17	8.00	0.60
Haemoglobin (g/dL)	12.78	13.00	13.38	0.79
Haematocrit (%)	54.00	50.90	53.86	3.05
Platelets (10^3/mm^3)	270.0	229.3	242.7	26.02
Chemical composition of plasma
Total protein (g/dL)	6.40	6.95	6.65	0.26
Albumin (g/dL)	3.27	3.63	3.27	0.18
Lactate dehydronase (U/L)	937.7^a	851.5^ab	815.3^b	28.1
Total cholesterol (mg/dL)	96.83	95.17	89.00	4.50
Triglyceride (mg/dL)	61.40^a	52.17^ab	40.17^b	3.46
Blood urea nitrogen (mg/dL)	15.13^a	12.87^ab	10.10^b	1.02
HDL-cholesterol^3 (mg/dL)	39.67	38.17	38.50	2.83
LDL-cholesterol^4 (mg/dL)	45.33	43.83	40.00	2.71
Cortisol (µg/dL)	4.35^a	2.44^b	2.40^b	0.43
^1Mean of 12 pigs individually housed in each treatment.
^2The basal diet was supplemented with bamboo charcoal: C, no supplement; T1, 0.3% and T2, 0.6%.
^3High density lipoprotein-cholesterol.
^4Low density lipoprotein-cholesterol.
^a,bValues in the same row with different superscripts differ at P < 0.05.

Although bamboo charcoal supplemented-diet had no effect on total IgM and IgA levels, it had positively affected the IgG level, which was significantly higher (P<0.05; Table 4).

Table 4. The effects of bamboo charcoal on antibodies concentration of IgM, IgG and IgA in fattening pigs.¹

	Treatment^2
Parameters	C	T1	T2	Standard error mean (SEM)
Immunoglobulin (mg/mL)
Immunoglobulin M	2.30	2.51	2.37	0.59
Immunoglobulin G	7.55^b	9.57^a	10.48^a	0.62
Immunoglobulin A	2.35	2.30	2.24	0.30
^1Mean of 12 pigs individually housed in each treatment.
^2The basal diet was supplemented with bamboo charcoal: C, no supplement; T1, 0.3% and T2, 0.6%.
^a,bValues in the same row with different superscripts differ at P<0.05.

Faecal pH and noxious gas emissions from faeces were affected by bamboo charcoal supplemented-diet (Table 5). Faecal pH was significantly lower (P<0.05) in treatments and was not different (P>0.05) between T1 and T2. Emission of noxious gases (ammonia, methane, amine and hydrogen sulphide) was significantly lower (P<0.05) in T2, and T1 showed an intermediate gas emission between T2 and C. Bamboo charcoal did not affect the concentration of acetic acid, isobutyric acid and valeric acid in faeces, but significantly affected (P<0.05) the concentration of lactic acid, propionic acid, butyric acid and isovaleric acid. The concentration of lactic acid and butyric acid was lower (P<0.05) in treatments and was not different between T1 and T2, but the concentration of faecal propionic acid and isovaleric acid was significantly lower (P<0.05) only in T2 (Table 5).

Table 5. The effects of bamboo charcoal on pH, gas emission and concentration of volatile fatty acid (VFA) in faeces of fattening pigs.¹

	Treatment^2
Parameters	C	T1	T2	Standard error mean (SEM)
Faecal pH	6.356^b	6.684^a	6.864^a	0.082
Faecal gas emission (ppm)
Ammonia	8.08^a	5.84^ab	3.61^b	0.63
Methane	609.3^a	286.5^ab	231.9^b	97.9
Amine	41.42^a	26.35^ab	14.41^b	4.33
Hydrogen sulphide	12.86^a	8.82^ab	5.12^b	2.56
Faecal concentration of VFA (M/g)
Lactic acid	0.905^a	0.665^b	0.674^b	0.093
Acetic acid	2.320	2.022	2.179	0.126
Propionic acid	1.448^a	1.374^ab	1.147^b	0.072
Isobutyric acid	0.188	0.287	0.151	0.074
Butyric acid	1.285^a	0.797^b	0.770^b	0.095
Isovaleric acid	0.481^a	0.468^a	0.323^b	0.026
Valeric acid	0.081	0.048	0.022	0.023
^1Mean of 12 faecal samples analysed in each treatment.
^2The basal diet was supplemented with bamboo charcoal: C, no supplement; T1, 0.3% and T2, 0.6%.
^a,bValues in the same row with different superscripts differ at P<0.05.

Faecal Shigella was not detected in all treatments. Bamboo charcoal treatment significantly decreased (P<0.05) the count of faecal anaerobic total bacteria. Lactobacillus spp. was significantly higher (P<0.05), while E. coli and Salmonella were significantly lower (P<0.05) in treatments, and there was no difference between bamboo charcoal treatments (Table 6).

Table 6. The effects of bamboo charcoal on microflora population in faeces of fattening pigs.¹

	Treatment^2
Microflora counts, log10 cfu/g	C	T1	T2	Standard error mean (SEM)
Total bacteria	6.041^a	3.762^b	3.837^b	1.317
Lactobacillus spp.	5.153^b	7.140^a	7.804^a	0.221
Escherichia coli	3.560^a	1.259^b	1.000^b	0.514
Salmonella	4.568^a	1.515^b	N.D.^b	0.598
Shigella	N.D.	N.D.	N.D.
^1Mean of 12 faecal samples analysed in each treatment.
^2The basal diet was supplemented with bamboo charcoal: C, no supplement; T1, 0.3% and T2, 0.6%.
^a,bValues in the same row with different superscripts differ at P<0.05.

4. Discussion

Bamboo charcoal increased ADG and feed efficiency of fattening pigs in the present experiment. Ruttanavut et al. (2009) reported that bamboo charcoal powder slightly increased growth performance under similar environmental conditions due to increased villus surface area in ducks. It has been suggested that long villi have increased surface area and capability of absorption of available nutrients in human (Caspary 1992) and pigs (Zijlstra et al. 1996) and increased villus size induces cell proliferation in the crypt (Lauronen et al. 1998). Moreover, Kutlu et al. (2001) reported that wood charcoal has improved BW of broiler chicks due to increased feed intake, nutrient digestibility and improved feed efficiency. These studies support the findings of the present study where bamboo charcoal increased the growth performance and feed efficiency maybe due to improved nutrient utilisation and increased microscopic parameters and protuberated cells by increased villi size and epithelial cells of fattening pigs.

As much as 0.6% bamboo charcoal decreased the concentration of LDH, triglyceride and BUN. LDH plays an important role in cellular respiration through catalysation by which pyruvate from glucose is converted into usable energy as lactate for cells. LDH is released into the bloodstream when tissues are damaged by injury or disease (Joseph et al. 2002). BUN is the amount of urea nitrogen in the blood produced as a waste during protein metabolism. Disease or damaged kidneys cause an elevated BUN, because they fail to clear urea from the bloodstream (Johnson et al. 1972). Bamboo charcoal reduced BUN concentration in the blood of fattening pigs, which may prolong the time required to reach the critical concentration of BUN and allow for a medical treatment.

Bamboo charcoal for fattening pigs increased the concentration of total serum IgG, but decreased cortisol concentration in this experiment. Cortisol is a steroid hormone or glucocorticoid produced by the adrenal gland and released in response to stress. Its primary functions are to increase blood sugar by gluconeogenesis, suppress the immune system, aid in fat, protein and carbohydrate metabolism and decrease bone formation (Tao 2009). Moreover, cortisol prevents proliferation of T-cells by rendering the interleukin and T-cell growth factor. Cortisol also has a negative-feedback effect on interleukin-1, which is useful in combating some diseases such as hypothalamus (Palacios and Sugawara 1982). Therefore, a decreased cortisol as a result of the addition of bamboo charcoal to diet protects fattening pigs from diseases or stress. The addition of bamboo charcoal also increased IgG concentration, but did not affect IgM and IgA concentration. IgM is the first antibody formed when white blood cells are initially exposed to an antigen and it is a pentomer molecule with five linked antibodies. When IgG exposed to an antigen for a second time, a pig builds very high levels of antibodies, mostly in the class of IgG. White blood cells switch from synthesising IgM to synthesising IgG after continued antigen exposure. IgA also referred to as secretory antibody and was found at higher concentrations in the fluids of mucous membranes (respiratory, gastrointestinal, reproductive tracts and eyes). Finally, immunoglobulin D (IgD) and immunoglobulin E (IgE) function as allergic and anaphylactic responses (McGlone and Pond 2002).

As much as 0.6% bamboo charcoal decreased noxious gas emission from fattening pigs in this experiment. Wood charcoal have the potential to provide an effective way to neutralise anti-nutrients related to feed and negative effects of gases, toxins and other substances that are related to digestion and fermentation in the gastrointestinal tract. It also provides an economical way to eliminate noxious substances (Kutlu et al. 2001). Bamboo charcoal possess a higher adsorption capacity than wood charcoal because of the special structure of micro-pores of the bamboo stem (ChungPin et al. 2004). Bamboo charcoal is known to have about fourfolds more cavities, threefolds more mineral contents and fourfolds better absorption rate (Zhao et al. 2008). Asada et al. (2002) reported that bamboo charcoal decreased the odour of ammonia, benzene, toluene, indole and skatole because of pore volume and micro-pore range. Therefore, the micro-pores of bamboo charcoal could have suppressed the noxious gas emission of faeces from fattening pigs.

Bamboo charcoal increased the beneficial bacteria (Lactobacillus spp.) and decreased the harmful bacteria (E. coli and Salmonella spp.) in fattening pigs. Activated charcoal decreased toxins in ruminants (Poage et al. 2000), bacterial toxin (Buck and Bratich 1986) and E. coli (Naka et al. 2001). Buck and Bratic (1986) reported the effectiveness of activated charcoal to reduce gastrointestinal tract infections caused by bacterial toxins in human. They also reported that rapid administration of activated charcoal is a suitable practice to prevented toxicosis and death. They indicated that the time delay between inoculation with the target organism and dosing of activated charcoal inhibited the binding capability of the activated charcoal. Anjaneyulu et al. (1993) reported that dietary of wood charcoal reduced the effects of toxins in diet by adsorption and thereby preventing its absorption from the intestine. The present study suggests that bamboo charcoal improved the environment of intestine by increasing the beneficial microflora of fattening pigs.

5. Conclusion

Bamboo charcoal increased the growth performance and feed efficiency, while decreased noxious gas emission and faecal harmful microflora in fattening pigs. Moreover, such bamboo charcoal may protect pigs from infection and reduce stress due to decreased cortisol concentration and increased IgG concentration of serum or blood cell in fattening pigs. Bamboo charcoal is expected to improve swine production as a result of improved gastrointestinal environment of fattening pigs.

Acknowledgements

This work was supported by the Priority Research Centers Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology (2009-0093813) and Gyeongnam National University of Science and Technology Grant at 2012. The authors would like also to thank Borim Inc., Jinju, Korea for their kind help with supporting materials. This research was also supported by iPET (Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries), Ministry for Food, Agriculture, Forestry and Fisheries, Repulic of Korea.