Background: Determination of the endogenous loss of fat(ELF) is used to adjust for the estimation of true total tract digestibility(TTTD) of fat in diets and ingredients.Any factor which affected ELF may further affec...Background: Determination of the endogenous loss of fat(ELF) is used to adjust for the estimation of true total tract digestibility(TTTD) of fat in diets and ingredients.Any factor which affected ELF may further affect the digestibility of fat,including sources and concentrations of fat and fiber in the diet.There are some reports of determining the ELF using regression methods based on different levels of fat intake,while reports on effects of dietary fiber content and different fiber-rich ingredients in pig diets on ELF are very limited.Therefore,the objective of this study was to determine the effects of dietary fiber content and different fiber-rich ingredients on endogenous losses of fat and fatty acids at the end of ileum and throughout the entire intestinal tract in growing pigs.Methods: In Exp.1,the effect of fiber content on endogenous loss of fat was determined using six growing pigs(Duroc × Landrace × Yorkshire;27.6 ± 2.4 kg),fitted with a T-cannula at the end of ileum.The experimental design was a 6 × 6 complete Latin square design with six periods of feeding and six diets.The six experimental fat-free diets were formulated to include graded levels of neutral detergent fiber(NDF)(0,40,80,120,160 and 200 g/kg) and soybean hull(SH) was the only fiber source,providing 0,75,150,225,300 and 375 g/kg,respectively.Chromic oxide was included at4 g/kg in all diets as an indigestible marker.In Exp.2,six crossbred growing barrows(27.6 ± 1.6 kg) were used and the experimental design was the same as for Exp.1.The six fat-free diets were formulated to include six common fiber-rich ingredients and the concentration of NDF was 100 g/kg.The six fiber-rich ingredients were defatted rice bran(DRB),sugar beet pulp(SBP),rice hull(RH),corn germ meal(CGM),SH and wheat bran(WB) and they were fed at represented250,270,145,250,170 and 280 g/kg in the diet,respectively.Results: In Exp.1,the endogenous loss of fatty acids profile did not change as dietary NDF increased in growing pigs.The endogenous losses of fat,C16:0,C18:0,C18:1,C18:2,total unsaturated fatty acids(UFA) and total saturated fatty acids(SFA) in growing pigs at the end of ileum and throughout the entire intestinal tract increased linearly as NDF content of diets increased.The endogenous losses of fat,as well as C16:0 and C18:0 throughout the entire intestinal tract also increased quadratically as NDF content of diets increased.The ELF increased from 0.71 to 3.14 g/kg of dry matter intake(DMI) and 0.56 to 8.21 g/kg DMI at the end of ileum and throughout the entire intestinal tract in growing pigs,respectively.The ELF occurred in the hindgut except for the growing pigs fed 0 and 4% NDF in their diets.The endogenous losses of C16:0 and UFA occurred primarily in the upper regions of the gut and the greatest endogenous losses of C18:0 occurred in the hindgut.The endogenous losses of fat,individual SFA and total SFA throughout the entire intestinal tract were much greater than that at the end of ileum.However,the endogenous losses of individual UFA and total UFA were less throughout the intestinal tract than at the end of ileum.In Exp.2,the endogenous losses of fat at the end of ileum were greater in growing pigs fed CGM or WB diets.The endogenous loss of fatty acids profile changed to a slight degree at the end of ileum that the endogenous loss of UFA(particularly C18:1 and C18:2) in growing pigs fed CGM or WB diets were greater(P < 0.01) than that for the other four diets.The greatest(P < 0.01) endogenous loss of SFA(particularly C18:0) was in growing pigs fed the RH diet.The endogenous losses of fat,C16:0,C18:0 and SFA over the entire intestinal tract were much greater in growing pigs fed CGM or WB diets,whereas the lowest values were in growing pigs fed DRB diet.The ELF at the end of ileum in growing pigs fed CGM or WB diets were 3.50 or 4.17 g/kg DMI,respectively,and the ELF over the entire intestinal tract was 7.23 or 7.38 g/kg DMI.The contribution in percentage of ELF in the upper gut was greater than that in the hindgut of growing pigs fed DRB and RH diets,while the ELF in the upper gut and hindgut were equal in growing pigs fed SBP,CGM and WB diets.On the whole,the endogenous losses of C18:1 and C18:2 throughout the entire intestinal tract in growing pigs fed the six fiber-rich ingredients diets were less than losses at the end of ileum,whereas the endogenous loss of fat,C16:0,C18:0 and SFA were greater throughout the intestinal tract than at the end of ileum.Conclusion: The profile of loss in endogenous fatty acids did not change as dietary NDF increased in growing pigs and the endogenous losses of fatty acids(C16:0,C18:0,C18:1 and C18:2) fat,UFA and SFA increased linearly as NDF content increased in the diets of pigs.The endogenous losses of fat or fatty acids at the end of ileum were greater in growing pigs fed RH,CGM or WB diets.The endogenous losses of fat,fatty acids(C16:0 and C18:0) and SFA were greater over the entire intestinal tract in pigs fed CGM or WB diet,while these values were the lowest in growing pigs fed the DRB diet.The contribution in percentage losses of fat in the upper gut were greater than in the hindgut of growing pigs fed DRB and RH diets,while the contribution of losses of fat in the upper gut and hindgut were equal in growing pigs fed SBP,CGM and WB diets.In addition,the endogenous loss of individual or total UFA was less over the entire intestinal tract of growing pigs fed fiber diets than that at the end of ileum,and the greatest endogenous losses of fat,individual or total SFA were over the entire intestinal tract.Therefore,differences in fiber content and the nature of fiber-rich ingredients in diets of pigs have different effects to the endogenous losses of fat or fatty acids.Considering the requirement of fat or fatty acids of pigs,careful attention must be paid that the endogenous losses of fat and fatty acids when fiber ingredients are used in diets of pigs.展开更多
This study was to investigate time-course effects of different types of dietary fiber on the energy values,fecal microbiota and short-chain fatty acid(SCFA)concentration in growing pigs.A total of 24 barrows(initial b...This study was to investigate time-course effects of different types of dietary fiber on the energy values,fecal microbiota and short-chain fatty acid(SCFA)concentration in growing pigs.A total of 24 barrows(initial body weight,19.8±0.5 kg)were assigned to 4 dietary treatments based on body weight(BW)in a completely randomized design,including a basal diet(CON)and 3 fiber-rich diets replacing corn,soybean meal and soybean oil in the CON diet with 20%sugar beet pulp(SBP),defatted rice bran(DFRB)or soybean hull(SBH),respectively.Fresh feces were sampled on d 7,14 and 21,followed by 5 d total feces and urine collections.The results showed that there were no differences in DE and ME between any of the fiber ingredients on d 7,14 or 21.However,fiber inclusion decreased the DE and ME of the diet(P<0.05)regardless of the time effect.Principal coordinate analysis(PCoA)revealed distinctly different microbial communities on the DFRB diet and SBH diet across different times(P<0.05)and the fecal microbiota of the 4 diet groups demonstrated notably distinct clusters at each time point(P<0.05).With adaptation time increased from 7 to 21 d,cellulose-degrading bacteria and SCFA-producing bacteria(e.g.,Ruminococcaceae_UCG-014,Rikenellaceae_RC9_gut_group and Bifidobacterium)increased in the fiber inclusion diets,and pathogenic genera(e.g.,Streptococcus and Selenomonas)were increased in the basal diet(P<0.05).Furthermore,the gut microbiota of growing pigs adapted more easily and quickly to the SBP diet compared to the DFRB diet,as reflected by the concentration of propionate,butyrate,isovalerate and total SCFA which increased with time for growing pigs fed the DFRB diet(P<0.05).Collectively,our results indicated at least 7 d adaptation was required to evaluate the energy values of fiber-rich ingredients,as the hindgut microbiota of growing pigs may need more time to adapt to a high fiber diet,especially for insoluble dietary fiber.展开更多
用中空纤维膜接触器（FMC）作解吸装置,选取N-甲基二乙醇胺（MDEA）-二乙醇胺（DEA）混合吸收剂为富CO2吸收液进行膜法解吸及再生实验,考察了解吸温度、解吸压力和液相流速对解吸效果的影响,研究了再生液的CO2二次吸收和解吸性能.结果表...用中空纤维膜接触器（FMC）作解吸装置,选取N-甲基二乙醇胺（MDEA）-二乙醇胺（DEA）混合吸收剂为富CO2吸收液进行膜法解吸及再生实验,考察了解吸温度、解吸压力和液相流速对解吸效果的影响,研究了再生液的CO2二次吸收和解吸性能.结果表明,在取样时间20和40 min下,混合吸收剂最佳溶质摩尔比为MDEA：DEA=1：0.6.适当增大解吸温度、液相流速及负压压强可有效提高CO2的释放流量和解吸率.60℃时CO2释放流量峰值为101.29 m L/min（峰值前移）,CO2最终解吸率为61.51%,比30℃时分别提高了56.14%和50.5%;解吸压力20 k Pa时CO2释放流量峰值和最终解吸率分别为96.17 m L/min（峰值前移）和58.66%,比65 k Pa时分别提高了62.21%和16.85%.流速为0.08 m/s时CO2释放流量峰值为88.65 m L/min（峰值未前移）,最终解吸率为55.63%,比0.02 m/s时分别提高了43.45%和30.13%.MDEA-DEA再生液循环使用5次后CO2吸收容量为原液的70%,二次解吸率为原液的60%,无明显下降.膜法解吸混合富CO2吸收液效果良好,且再生液具有优异的二次吸收和解吸性能.展开更多
采用中空纤维膜接触器(FMC)作为解吸装置,对吸收了CO_2的N-甲基二乙醇胺(MDEA)溶液(富液)进行膜法解吸实验。考察了CO_2负荷、解吸温度、解吸压力、富液流速和N_2吹扫流量对CO_2解吸率的影响。结果表明,富液中CO_2负荷越大、解吸温度越...采用中空纤维膜接触器(FMC)作为解吸装置,对吸收了CO_2的N-甲基二乙醇胺(MDEA)溶液(富液)进行膜法解吸实验。考察了CO_2负荷、解吸温度、解吸压力、富液流速和N_2吹扫流量对CO_2解吸率的影响。结果表明,富液中CO_2负荷越大、解吸温度越高、解吸压力越低、富液流速越大、N_2吹扫流量越大,则CO_2解吸率越高。综合考虑,本实验优选的工艺条件为解吸温度45~65℃,解吸压力10~30 k Pa,富液流速0.08 m/s,N_2吹扫流量200 m L/min。展开更多
基金supported by the Prevention and Control of Nutritional Metabolism and Toxic Diseases in Livestock and Poultry(2016YFD0501204)the 111 Project(B16044)
文摘Background: Determination of the endogenous loss of fat(ELF) is used to adjust for the estimation of true total tract digestibility(TTTD) of fat in diets and ingredients.Any factor which affected ELF may further affect the digestibility of fat,including sources and concentrations of fat and fiber in the diet.There are some reports of determining the ELF using regression methods based on different levels of fat intake,while reports on effects of dietary fiber content and different fiber-rich ingredients in pig diets on ELF are very limited.Therefore,the objective of this study was to determine the effects of dietary fiber content and different fiber-rich ingredients on endogenous losses of fat and fatty acids at the end of ileum and throughout the entire intestinal tract in growing pigs.Methods: In Exp.1,the effect of fiber content on endogenous loss of fat was determined using six growing pigs(Duroc × Landrace × Yorkshire;27.6 ± 2.4 kg),fitted with a T-cannula at the end of ileum.The experimental design was a 6 × 6 complete Latin square design with six periods of feeding and six diets.The six experimental fat-free diets were formulated to include graded levels of neutral detergent fiber(NDF)(0,40,80,120,160 and 200 g/kg) and soybean hull(SH) was the only fiber source,providing 0,75,150,225,300 and 375 g/kg,respectively.Chromic oxide was included at4 g/kg in all diets as an indigestible marker.In Exp.2,six crossbred growing barrows(27.6 ± 1.6 kg) were used and the experimental design was the same as for Exp.1.The six fat-free diets were formulated to include six common fiber-rich ingredients and the concentration of NDF was 100 g/kg.The six fiber-rich ingredients were defatted rice bran(DRB),sugar beet pulp(SBP),rice hull(RH),corn germ meal(CGM),SH and wheat bran(WB) and they were fed at represented250,270,145,250,170 and 280 g/kg in the diet,respectively.Results: In Exp.1,the endogenous loss of fatty acids profile did not change as dietary NDF increased in growing pigs.The endogenous losses of fat,C16:0,C18:0,C18:1,C18:2,total unsaturated fatty acids(UFA) and total saturated fatty acids(SFA) in growing pigs at the end of ileum and throughout the entire intestinal tract increased linearly as NDF content of diets increased.The endogenous losses of fat,as well as C16:0 and C18:0 throughout the entire intestinal tract also increased quadratically as NDF content of diets increased.The ELF increased from 0.71 to 3.14 g/kg of dry matter intake(DMI) and 0.56 to 8.21 g/kg DMI at the end of ileum and throughout the entire intestinal tract in growing pigs,respectively.The ELF occurred in the hindgut except for the growing pigs fed 0 and 4% NDF in their diets.The endogenous losses of C16:0 and UFA occurred primarily in the upper regions of the gut and the greatest endogenous losses of C18:0 occurred in the hindgut.The endogenous losses of fat,individual SFA and total SFA throughout the entire intestinal tract were much greater than that at the end of ileum.However,the endogenous losses of individual UFA and total UFA were less throughout the intestinal tract than at the end of ileum.In Exp.2,the endogenous losses of fat at the end of ileum were greater in growing pigs fed CGM or WB diets.The endogenous loss of fatty acids profile changed to a slight degree at the end of ileum that the endogenous loss of UFA(particularly C18:1 and C18:2) in growing pigs fed CGM or WB diets were greater(P < 0.01) than that for the other four diets.The greatest(P < 0.01) endogenous loss of SFA(particularly C18:0) was in growing pigs fed the RH diet.The endogenous losses of fat,C16:0,C18:0 and SFA over the entire intestinal tract were much greater in growing pigs fed CGM or WB diets,whereas the lowest values were in growing pigs fed DRB diet.The ELF at the end of ileum in growing pigs fed CGM or WB diets were 3.50 or 4.17 g/kg DMI,respectively,and the ELF over the entire intestinal tract was 7.23 or 7.38 g/kg DMI.The contribution in percentage of ELF in the upper gut was greater than that in the hindgut of growing pigs fed DRB and RH diets,while the ELF in the upper gut and hindgut were equal in growing pigs fed SBP,CGM and WB diets.On the whole,the endogenous losses of C18:1 and C18:2 throughout the entire intestinal tract in growing pigs fed the six fiber-rich ingredients diets were less than losses at the end of ileum,whereas the endogenous loss of fat,C16:0,C18:0 and SFA were greater throughout the intestinal tract than at the end of ileum.Conclusion: The profile of loss in endogenous fatty acids did not change as dietary NDF increased in growing pigs and the endogenous losses of fatty acids(C16:0,C18:0,C18:1 and C18:2) fat,UFA and SFA increased linearly as NDF content increased in the diets of pigs.The endogenous losses of fat or fatty acids at the end of ileum were greater in growing pigs fed RH,CGM or WB diets.The endogenous losses of fat,fatty acids(C16:0 and C18:0) and SFA were greater over the entire intestinal tract in pigs fed CGM or WB diet,while these values were the lowest in growing pigs fed the DRB diet.The contribution in percentage losses of fat in the upper gut were greater than in the hindgut of growing pigs fed DRB and RH diets,while the contribution of losses of fat in the upper gut and hindgut were equal in growing pigs fed SBP,CGM and WB diets.In addition,the endogenous loss of individual or total UFA was less over the entire intestinal tract of growing pigs fed fiber diets than that at the end of ileum,and the greatest endogenous losses of fat,individual or total SFA were over the entire intestinal tract.Therefore,differences in fiber content and the nature of fiber-rich ingredients in diets of pigs have different effects to the endogenous losses of fat or fatty acids.Considering the requirement of fat or fatty acids of pigs,careful attention must be paid that the endogenous losses of fat and fatty acids when fiber ingredients are used in diets of pigs.
基金This work was funded by Agricultural Science and Technology Innovation Program(ASTIP-IAS07)Guizhou Science and Technology Support Program(2021-149).
文摘This study was to investigate time-course effects of different types of dietary fiber on the energy values,fecal microbiota and short-chain fatty acid(SCFA)concentration in growing pigs.A total of 24 barrows(initial body weight,19.8±0.5 kg)were assigned to 4 dietary treatments based on body weight(BW)in a completely randomized design,including a basal diet(CON)and 3 fiber-rich diets replacing corn,soybean meal and soybean oil in the CON diet with 20%sugar beet pulp(SBP),defatted rice bran(DFRB)or soybean hull(SBH),respectively.Fresh feces were sampled on d 7,14 and 21,followed by 5 d total feces and urine collections.The results showed that there were no differences in DE and ME between any of the fiber ingredients on d 7,14 or 21.However,fiber inclusion decreased the DE and ME of the diet(P<0.05)regardless of the time effect.Principal coordinate analysis(PCoA)revealed distinctly different microbial communities on the DFRB diet and SBH diet across different times(P<0.05)and the fecal microbiota of the 4 diet groups demonstrated notably distinct clusters at each time point(P<0.05).With adaptation time increased from 7 to 21 d,cellulose-degrading bacteria and SCFA-producing bacteria(e.g.,Ruminococcaceae_UCG-014,Rikenellaceae_RC9_gut_group and Bifidobacterium)increased in the fiber inclusion diets,and pathogenic genera(e.g.,Streptococcus and Selenomonas)were increased in the basal diet(P<0.05).Furthermore,the gut microbiota of growing pigs adapted more easily and quickly to the SBP diet compared to the DFRB diet,as reflected by the concentration of propionate,butyrate,isovalerate and total SCFA which increased with time for growing pigs fed the DFRB diet(P<0.05).Collectively,our results indicated at least 7 d adaptation was required to evaluate the energy values of fiber-rich ingredients,as the hindgut microbiota of growing pigs may need more time to adapt to a high fiber diet,especially for insoluble dietary fiber.
文摘用中空纤维膜接触器（FMC）作解吸装置,选取N-甲基二乙醇胺（MDEA）-二乙醇胺（DEA）混合吸收剂为富CO2吸收液进行膜法解吸及再生实验,考察了解吸温度、解吸压力和液相流速对解吸效果的影响,研究了再生液的CO2二次吸收和解吸性能.结果表明,在取样时间20和40 min下,混合吸收剂最佳溶质摩尔比为MDEA：DEA=1：0.6.适当增大解吸温度、液相流速及负压压强可有效提高CO2的释放流量和解吸率.60℃时CO2释放流量峰值为101.29 m L/min（峰值前移）,CO2最终解吸率为61.51%,比30℃时分别提高了56.14%和50.5%;解吸压力20 k Pa时CO2释放流量峰值和最终解吸率分别为96.17 m L/min（峰值前移）和58.66%,比65 k Pa时分别提高了62.21%和16.85%.流速为0.08 m/s时CO2释放流量峰值为88.65 m L/min（峰值未前移）,最终解吸率为55.63%,比0.02 m/s时分别提高了43.45%和30.13%.MDEA-DEA再生液循环使用5次后CO2吸收容量为原液的70%,二次解吸率为原液的60%,无明显下降.膜法解吸混合富CO2吸收液效果良好,且再生液具有优异的二次吸收和解吸性能.
文摘采用中空纤维膜接触器(FMC)作为解吸装置,对吸收了CO_2的N-甲基二乙醇胺(MDEA)溶液(富液)进行膜法解吸实验。考察了CO_2负荷、解吸温度、解吸压力、富液流速和N_2吹扫流量对CO_2解吸率的影响。结果表明,富液中CO_2负荷越大、解吸温度越高、解吸压力越低、富液流速越大、N_2吹扫流量越大,则CO_2解吸率越高。综合考虑,本实验优选的工艺条件为解吸温度45~65℃,解吸压力10~30 k Pa,富液流速0.08 m/s,N_2吹扫流量200 m L/min。
