Effects Of Adding Mannanoligosaccharides On Digestibility And Metabolism Of Nutrients,Ruminal Parameters, Digesta Passage And Immune Of Sheep

This study was carried out to investigate the effects of addingmannanoligosaccharides(MOS) to diets on digestibility and metabolism of nutrients,ruminal parameters,digesta passage and immune of sheep. A4×6two factorsexperiment design was chosen in trial one. There were four concentrate-to-roughagediets(20:80,30:70,40:60and50:50) and added to six dosages MOS(0.0%,0.4%,0.8%,1.2%,1.6%and2.0%) respectively. The gas production technique was used toresearch the gas and CH4production, in vitro dry matter digestibility(IVDMD), invitro crude protein digestibility(IVCPD), pH, NH₃-N concentration and volatile fattyacid(VFA) after cultured3,6,9,12and24h. The Multiple-Factors Associative EffectsIndex (MFAEI) also was to associatively evaluate results and made sure the bestassociative effect of concentrate-to-roughage and MOS level. A single factorexperiment design was chosen in trial two to five, and12crossbredwethers(Suffolk×Small tail Han-yang, average weight was28.04±2.07kg) fittedwith permanent rumen, duodenum and ileum terminal fistula were used. These studieswere conducted to indagate effects of adding MOS to sheep diets on digestibility andmetabolism of nutrients, ruminal parameters, digesta passage and immune. The resultsshowed:Trial one, Effects of adding mannan-oligosaccharide to differentconcentrate-to-roughage diets on ruminal fermentation in vitro: The IVDMD, IVCPD,pH, NH₃-N content, ratio of acetic acid to propionic acid, acetic acid and butyricmolar ratio were affected by concentrate-to-roughage significantly(P<0.05); while theIVCPD, pH and NH₃-N content were affected by MOS significantly(P<0.05). The gas and methane production were not impacted by two factors(P>0.05). The IVCPD, pH,NH₃-N content increased with the reducing of concentrate approximately, whileopposite to the IVDMD; and the IVCPD and NH₃-N content increased with the risingof MOS roughly, while opposite to the pH. The biggest associative effect was gainedin40:60concentrate-to-roughage diet when adding1.6%MOS.Trial two, Effects of adding MOS to diets on digestibility and metabolism ofnutrients in sheep: There were no significant impact on dry matter(DM), organicmatter(OM), nitrogen(N), neutral detergent fiber(NDF), acid detergent fiber(ADF),calcium(Ca) and phosphorus(P) apparent digestibility by MOS(P>0.05). However,the trend could be observed that adding MOS to sheep diets could increase theretained quantity and retention of N, digested quantity and digestibility of NDF andADF and decrease the quantity of NDF and ADF in feces(P<0.20).Trila three, Effects of adding MOS to diets on ruminal parameters in sheep:There were no significant influence on pH, total nitrogen, NH₃-N, urea nitrogen,protein nitrogen, total volatile fatty acid(TVFA) concentration, acetate, propionate,butyrate and other acids molar ratio and acetate/propionate in ruminal fluid of sheepby adding MOS(P>0.05). The mean of ruminal fluid protein nitrogen in1.6%MOSwas raised and the mean of serum urea nitrogen in1.6%and2.0%MOS wasdecreased significantly(P<0.05), and there was a tendency that MOS could reduceNH₃-N and urea nitrogen of ruminal fluid(P<0.20). The NH₃-N and urea nitrogen ofruminal fluid and serum urea nitrogen of sheep fed diets with MOS were lower thansheep fed diet without MOS, and protein nitrogen of ruminal fluid in1.6%and2.0%MOS was higher than0.0%MOS.Trial four, Effects of adding MOS to diets on digesta passage in sheep: MOS didnot influence the digesta passage and nutrients apparent digestibility at rumen,duodenum, ileum and feces significantly(P>0.05). The DM, OM, CP, NDF and ADFdigesta passage at rumen and duodenum were raised when adding MOS to sheep diets,while opposite to NDF and ADF digesta passage at ileum and DM, OM, CP, NDF andADF at feces. The DM, OM, CP, NDF and ADF apparent digestibility at stomachwere decreased when adding MOS to sheep diets, while opposite to DM, OM, CP,NDF and ADF apparent digestibility at small intestine and large intestine. Trial five, Effects of adding MOS to diets on immune function and serumbiochemical indicator in sheep: The mean of serum glutathione peroxidase(GSH-Px),total superoxide dismutase(T-SOD), total antioxidant capacity(T-AOC) vitality ofsheep fed diets with MOS were significant higher than sheep fed diet withoutMOS(P<0.05), and the serum malondialdehyde(MDA) concentration was significantlower than the latter(P<0.05). There were no significant impact on serumImmunoglobulin A(IgA), Immunoglobulin G(IgG), Complement3(C3), Interleukin2(IL-2), nitric oxide(NO) and nitric oxide synthase(NOS) of sheep by addingMOS(P>0.05).