Efficacy and role of inulin in mitigation of enteric sulfur-containing odor in pigs.
BACKGROUND
The efficacy and role of inulin in the mitigation of enteric sulfur-containing odor gases hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) in pigs were examined in this study. Twelve Duroc × Landrace × Yorkshire male finisher pigs (60.7 ± 1.9 kg), housed individually in open-circuit respiration chambers, were randomly assigned to two dietary groups, namely basal diet (control) and basal diet supplemented with 1% (w/w) inulin. At the end of the 45 day experiment, pigs were slaughtered and volatile fatty acid (VFA) concentration, sulfate radical (SO42-) concentration, population of sulfate-reducing bacteria (SRB) and expression of methionine gamma-lyase (MGL) gene were determined in contents from the caecum, colon (two segments) and rectum. Metabonomic analysis was used to compare differences in biochemical composition, and the Illumina MiSeq procedure to investigate differences in bacterial components, in the different parts of the large intestine between inulin-supplemented and inulin-free (control) groups.


RESULTS
Inulin decreased (P < 0.05) the average daily enteric H2S and CH3SH production by 12.4 and 12.1% respectively. The concentrations of acetate, propionate and butyrate in the large intestinal content were significantly increased (P < 0.05) with inulin treatment, whereas valerate concentration and MGL mRNA expression decreased (P < 0.05). The growth of Lactobacillus, Butyrivibrio, Pseudobutyrivibrio, Bifidobacterium and Clostridium butyricum was stimulated, while that of Desulfovibrio, the dominant SRB, was inhibited, and there was an accumulation of SO42-in the large intestinal content of the inulin-supplemented pigs, suggesting that inulin mitigates H2S generation from the SO42-reduction pathway by reducing the growth of SRB.


CONCLUSIONS
The results showed that inulin mitigates CH3SH generation via three methionine degradation metabolic pathways and H2S generation from two cysteine degradation metabolic pathways, thus resulting in increased synthesis of these two sulfur-containing amino acids in the pig large intestine. © 2016 Society of Chemical Industry.
College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
Yuan-Fan
YF
Deng
College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
Yuan-Yuan
YY
Liu
College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
Yi-Tao
YT
Zhang
College of Animal Science, South China Agricultural University, Guangzhou 510642, China.|Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou, China.|Guangdong Enterprise Laboratory of Healthy Animal Husbandry and Environment Control, Xinxing, China.
Yan
Y
Wang
Laboratory of Animal Production, Institute of Tropical Agriculture, Universiti Putra Malaysia, Serdang 43400, Malaysia.
Juan-Boo
JB
Liang
Section of Veterinary Science and Animal Production, Department of Emergency and Organ Transplantation (DETO), University of Study of Bari 'Aldo Moro', I-70010, Valenzano, Italy.
Vincenzo
V
Tufarelli
Section of Veterinary Science and Animal Production, Department of Emergency and Organ Transplantation (DETO), University of Study of Bari 'Aldo Moro', I-70010, Valenzano, Italy.
Vito
V
Laudadio
College of Animal Science, South China Agricultural University, Guangzhou 510642, China.|Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou, China.|Guangdong Enterprise Laboratory of Healthy Animal Husbandry and Environment Control, Xinxing, China.
Xin-Di
XD
Liao
D000821:Animal Feed / Q000032:analysis; D000818:Animals; D013437:Carbon-Sulfur Lyases / Q000235:genetics / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D007420:Intestine, Large / Q000187:drug effects / Q000382:microbiology; D007444:Inulin / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D055442:Metabolome / Q000187:drug effects*; D009812:Odorants / Q000032:analysis*; D012336:RNA, Ribosomal, 16S; D013431:Sulfates / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism; D016999:Sulfur-Reducing Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D034421:Sus scrofa / Q000254:growth & development* / Q000378:metabolism / Q000382:microbiology
D005232:Fatty Acids, Volatile; D012336:RNA, Ribosomal, 16S; D013431:Sulfates; D013438:Sulfhydryl Compounds; C069025:sulfate radical; D007444:Inulin; D013437:Carbon-Sulfur Lyases; C021558:L-methionine gamma-lyase
fermentation; inulin; pig; sulfate-reducing bacteria; sulfur-containing odor