The objective of this study is to investigate the effects of free gossypol in cottonseed meal(CM)on the growth and intestinal health of grass carp,as well as to determine whether free gossypol is the primary factor re...The objective of this study is to investigate the effects of free gossypol in cottonseed meal(CM)on the growth and intestinal health of grass carp,as well as to determine whether free gossypol is the primary factor restricting highlevel inclusion of cottonseed meal.This study was designed with five groups:the control group(32%soybean concentrate protein),the CM group(44%CM),the cottonseed protein concentrate(CPC)group(33%CPC),and the CPC and control groups with 400 and 600 mg/kg gossypol added,designated as CON,CM,CPC,CPC+GP,and CON+GP,respectively.The experiment lasted eight weeks,and each group had three replicates.This experiment employed one-way ANOVA and Duncan's multiple comparisons of the means.The findings revealed that in comparison to the CON group,the growth of fish in the CM,CPC+GP,and CON+GP groups significantly decreased.Intestinal inflammation damage was observed.This was indicated by a significant upregulation of proinflammatory factors,including tnf-α,nf-κb,il-6,il-8,il-12β,and il-1β,along with significant downregulation of anti-inflammatory factors,including tgf-β1,il-15,and il-10.Additionally,significant downregulation of antioxidant enzyme-related genes,including nrf2,cat,CuZnsod,gpx4,and gpx1,was observed and the intestinal physical barrier function was compromised.In addition,the intestinal microbiota composition was affected,with a significant reduction in Bacillus and Cetobacterium abundances and a remarkable increase in the abundance of Aeromonas,resulting in dysregulation of the intestinal microbiota function.However,in comparison to the CM group,the growth rate of fish in the CPC group exhibited a marked increase;nonetheless,it persisted at a level lower than that observed in the CON group and the degree of intestinal damage was significantly improved.Additionally,the intestinal microbiota structure was found to be similar to that of the CON group.In conclusion,excessive CM negatively affects grass carp growth and intestinal health,whereas replacing CM with CPC mitigates these effects.Adding gossypol equivalent to CM group in CON and CPC diets reduces growth performance and impairs intestinal function,indicating gossypol as a primary limiting factor for high CM inclusion in diets.展开更多
In order to further reduce the damage rate in threshing seed corn,a seed corn threshing testbed with variable diameter and spacing that can realize dynamic adjustment of parameters,such as feed quantity,rotating speed...In order to further reduce the damage rate in threshing seed corn,a seed corn threshing testbed with variable diameter and spacing that can realize dynamic adjustment of parameters,such as feed quantity,rotating speed of the threshing device,threshing spacing of the threshing units,was designed in this research.The software of finite element analysis ANSYS Workbench was applied to do modal analysis on the threshing axis designed for variable diameter and spacing of seed corn.The first 8 orders of natural frequencies were distributed in 201.12-1640.20 Hz,with corresponding vibration amplitude in 5.86-27.04 mm,showing reasonable structural design of the threshing axis,which could realize effective seed corn threshing and conveying.Discrete element method was applied to do simulation analysis on the seed corn threshing and conveying process with variable diameter and spacing.Under the condition of different feed quantity,different rotating speed of the thresher,the moving speed of corn clusters and contact force among clusters were measured through simulation,and the working characteristics of the threshing testbed for low-damage and dynamic threshing and conveying of seed corn with variable diameter and spacing were revealed.Working performance test results of the testbed of seed corn with variable diameter and spacing showed that,when the rotating speed of the threshing axis was 190-290 r/min,feed quantity was 1.80-3.80 kg/s,the damage rate of seed corn was 0.32%-0.63%,threshing rate was 99.20%-99.82%,and content impurity rate was 4.23%-5.86%,the mass of threshed corn grains first increased and then decreased along the axial direction.The test verification process was in line with the simulation results;thus,the test results could satisfy the requirements in design and actual operation.展开更多
文摘The objective of this study is to investigate the effects of free gossypol in cottonseed meal(CM)on the growth and intestinal health of grass carp,as well as to determine whether free gossypol is the primary factor restricting highlevel inclusion of cottonseed meal.This study was designed with five groups:the control group(32%soybean concentrate protein),the CM group(44%CM),the cottonseed protein concentrate(CPC)group(33%CPC),and the CPC and control groups with 400 and 600 mg/kg gossypol added,designated as CON,CM,CPC,CPC+GP,and CON+GP,respectively.The experiment lasted eight weeks,and each group had three replicates.This experiment employed one-way ANOVA and Duncan's multiple comparisons of the means.The findings revealed that in comparison to the CON group,the growth of fish in the CM,CPC+GP,and CON+GP groups significantly decreased.Intestinal inflammation damage was observed.This was indicated by a significant upregulation of proinflammatory factors,including tnf-α,nf-κb,il-6,il-8,il-12β,and il-1β,along with significant downregulation of anti-inflammatory factors,including tgf-β1,il-15,and il-10.Additionally,significant downregulation of antioxidant enzyme-related genes,including nrf2,cat,CuZnsod,gpx4,and gpx1,was observed and the intestinal physical barrier function was compromised.In addition,the intestinal microbiota composition was affected,with a significant reduction in Bacillus and Cetobacterium abundances and a remarkable increase in the abundance of Aeromonas,resulting in dysregulation of the intestinal microbiota function.However,in comparison to the CM group,the growth rate of fish in the CPC group exhibited a marked increase;nonetheless,it persisted at a level lower than that observed in the CON group and the degree of intestinal damage was significantly improved.Additionally,the intestinal microbiota structure was found to be similar to that of the CON group.In conclusion,excessive CM negatively affects grass carp growth and intestinal health,whereas replacing CM with CPC mitigates these effects.Adding gossypol equivalent to CM group in CON and CPC diets reduces growth performance and impairs intestinal function,indicating gossypol as a primary limiting factor for high CM inclusion in diets.
基金financially supported by Key Science and Technology Project of Gansu Province(Grant No.21ZD10NF003-4-01)Department of Agriculture and Rural Areas of Gansu Province Agricultural Machinery Equipment Remediation Project(Grant No.niyf2022-02)+1 种基金Fuxi Young Talents Fund of Gansu Agricultural University(Grant No.Gaufx-03Y01)Youth Tutor Fund of Gansu Agricultural University(Grant No.GAU-QDFC-2021-08).
文摘In order to further reduce the damage rate in threshing seed corn,a seed corn threshing testbed with variable diameter and spacing that can realize dynamic adjustment of parameters,such as feed quantity,rotating speed of the threshing device,threshing spacing of the threshing units,was designed in this research.The software of finite element analysis ANSYS Workbench was applied to do modal analysis on the threshing axis designed for variable diameter and spacing of seed corn.The first 8 orders of natural frequencies were distributed in 201.12-1640.20 Hz,with corresponding vibration amplitude in 5.86-27.04 mm,showing reasonable structural design of the threshing axis,which could realize effective seed corn threshing and conveying.Discrete element method was applied to do simulation analysis on the seed corn threshing and conveying process with variable diameter and spacing.Under the condition of different feed quantity,different rotating speed of the thresher,the moving speed of corn clusters and contact force among clusters were measured through simulation,and the working characteristics of the threshing testbed for low-damage and dynamic threshing and conveying of seed corn with variable diameter and spacing were revealed.Working performance test results of the testbed of seed corn with variable diameter and spacing showed that,when the rotating speed of the threshing axis was 190-290 r/min,feed quantity was 1.80-3.80 kg/s,the damage rate of seed corn was 0.32%-0.63%,threshing rate was 99.20%-99.82%,and content impurity rate was 4.23%-5.86%,the mass of threshed corn grains first increased and then decreased along the axial direction.The test verification process was in line with the simulation results;thus,the test results could satisfy the requirements in design and actual operation.