Emerging evidence shows the trend of using safe and natural preservatives like bacteriocins in food processing.The increasing demand by the food industry to extend keeping quality and prevent spoilage of various food ...Emerging evidence shows the trend of using safe and natural preservatives like bacteriocins in food processing.The increasing demand by the food industry to extend keeping quality and prevent spoilage of various food products has appealed for new preservatives and new methods of conservation.Further,to discover the novel spectrum of antimicrobial compounds that could effectively battle food-borne pathogens,bacteriocins have been intensively studied in the last few years.Recently,great attention has been paid to the application of lactic acid-bacterial bacteriocins targeting food spoilage-causing or pathogenic microorganisms with no significant side effects.Different mechanisms of action like pore-formation,retarding cell-wall/nucleic acid/protein synthesis have been proposed and described for diverse bacteriocins.Therefore,the syntheses,purification of bacteriocins in addition to their applications as antimicrobial and preservative agents in food processing are reviewed in detail.The review will also discuss the preservative effect of bacteriocins and their combinations having multiple modes of action(hurdle approach)to reduce the microbial load as well as antimicrobial resistance.展开更多
As a new type of environmental pollutants,microplastics have gradually attracted people s attention.A large number of plastics discharged into the environment by human beings are constantly aging and breaking,and fina...As a new type of environmental pollutants,microplastics have gradually attracted people s attention.A large number of plastics discharged into the environment by human beings are constantly aging and breaking,and finally become microplastics.Microplastics can adsorb pollutants in the environment,and their components have certain toxicity,which can cause different degrees of harm to organisms.Due to the structural characteristics of microplastic particles,such as small particle size,large specific surface area,and their distribution in different environmental media,it is very difficult to accurately detect microplastics.Reliable collection and detection methods are the key to the study of environmental behavior of microplastics.In this study,the collection and detection methods of microplastics in the environment were reviewed,and the development direction of microplastics detection technology in the future was prospected.This study has a certain reference value for the related research and the prevention and treatment of micro-plastic pollution.展开更多
The present study here establishes a complete and effective method for isolating,purifying and identifying extracellular and intracellular peptides,and also describes the characters and bioactivities of peptides from ...The present study here establishes a complete and effective method for isolating,purifying and identifying extracellular and intracellular peptides,and also describes the characters and bioactivities of peptides from fermented casein with Lactobacillus helveticus.Intracellular peptides are much larger in quantity and more complex in composition than extracellular peptides,between which the correlation reveals proteolytic and metabolic mechanisms.In addition,totally 241 different peptide sequences were identified by Nano LC–MS/MS from casein(212)and Lactobacillus helveticus proteins(29).These casein-derived peptides mostly originated from-casein,followed byS1-casein,-casein,andS2-casein,and came from extracell(69)and intracell(143),in which common peptides have a total of 27.Forty-four of the identified peptides were previously described as bioactive,including angiotensinconverting enzyme(ACE)-inhibitory,antioxidant,immunomodulating,antimicrobial,DPP-IV inhibitory,antiamnesic and anticancer effects and so on.Thirteen peptides with the potential of some biological activities are obtained,which were described in previous studies.A total of 47 novel peptides of 5 to 26 amino acids that were not disclosed were obtained.The new sources of natural bioactive peptides may have the very high application value as potential new peptide drugs for treatment human diseases.The product peptide DELQDKIHPF found in both extracell and intracell was quantitatively analyzed using the MRM mode of UPLC-U3Q,23.1 and 9.76 ng/mL,respectively.The quantitative analysis of the potential bioactive peptide may also advance the production of peptide products in the future.展开更多
Pea(Pisum sativum L.)is an important source of plant proteins.However,the use of pea flour as a food ingredient is greatly limited due to its strong beany flavor.In this work,we investigated the effects of Lactobacill...Pea(Pisum sativum L.)is an important source of plant proteins.However,the use of pea flour as a food ingredient is greatly limited due to its strong beany flavor.In this work,we investigated the effects of Lactobacillus rhamnosus L08(L.rhamnosus L08)fermentation on the physicochemical characteristics,amino acids composition and volatile flavor compounds of pea flour.We found that L.rhamnosus L08 had the probiotic potential of utilizing pea flour as fermentation substrate.L.rhamnosus L08 fermentation significantly increased the content of most amino acids,and total amino acid content increased from 222.18 mg/g at 0 h to 262.35 mg/g at 6 h.A total of 44 volatile compounds were identified in pea flour.L.rhamnosus L08 fermentation increased the variety of acids and esters,while reduced the unpleasant flavor such as nonanal,decanal,octanal,1-hexanol and 2-ethyl-1-hexanol.The emulsifying stability and foam stability of pea flour were slightly enhanced during fermentation.Our results illustrate that lactic acid bacteria fermentation is a promising approach to eliminate undesirable aroma of pea flour.Moreover,this study provides theoretical support for the application of peas as high-quality protein source.展开更多
The antioxidative,antimicrobial,and anti-inflammatory properties of fermented sheep milk with L.fermentum (KGL4),as well as the generation of antioxidative and antimicrobial peptides,are evaluated in the study.Antioxi...The antioxidative,antimicrobial,and anti-inflammatory properties of fermented sheep milk with L.fermentum (KGL4),as well as the generation of antioxidative and antimicrobial peptides,are evaluated in the study.Antioxidative and antibacterial activities in sheep milk fermented with KGL4 increased with incubation hours,along with varied antioxidative properties (ABTS assay:35.12%,hydroxyl free radical scavenging assay:29.12%,superoxide free radical scavenging activity:36.38%).Antimicrobial activity of fermented sheep milk against E.faecalis (19 mm),S.typhimurium (15.67 mm),B.cereus (14 mm),and E.coli (13 mm) was also observed.Furthermore,after 48 h,the KGL4 showed maximum proteolysis (10.40 mg/ml) at 2.5% rate of addition sheep milk.The antioxidative and antimicrobial activities of fermented sheep milk fractions (3 kDa and 10 kDa permeates and retentates) were also investigated.The highest ABTS activity (26.90%) was found in 10 kDa permeate,whereas the 3 kDa retentate had higher hydroxyl free radical scavenging activity (69.20%) and 3 kDa permeate showed maximum superoxide free radical scavenging activity (32.85%).The 10 kDa retentate had shown maximum antimicrobial activity against S.typhimurium (13.67 mm) and E.faecalis (17.00 mm).Proteins spotted on 2D gel electrophoresis of KGL4 were varied from 10 to 70 kDa.RP-LC/MS was used to identify 5 novel peptide sequences from 2-D gel spots.Searches in the BIOPEP database confirmed the antioxidative and antimicrobial effects of the novel fermented sheep milk peptides.Fermented sheep milk with KGL4 (SMKGL4) significantly reduced excessive TNF-α,IL-6,& IL-1β production in LPS-activated RAW 264.7 cells.展开更多
Cow milk allergy is a major cause of food hypersensitivity in infants and children.However,to the best of our knowledge,there has been minimal research on the antigenicity of cow milk(CM).As it is currently unknown if...Cow milk allergy is a major cause of food hypersensitivity in infants and children.However,to the best of our knowledge,there has been minimal research on the antigenicity of cow milk(CM).As it is currently unknown if enzymatically hydrolyzed cow milk(HM)induces severe immunogenic responses,the potential allergenicity of HM was systematically evaluated in this work.HM effectively attenuated symptoms of weight loss and diarrhea,suppressed levels of mast cell tryptase,and relieved allergic inflammation of the intestine.Moreover,HM reduced the B220+cell count in mouse blood.In addition,in vitro studies demonstrated that gastrointestinal digestion of HM was not resistant to pepsin or trypsin.Thus,HM effectively alleviated allergic reactions and exhibited lower potential allergenicity.These results provide practical information for the future development of hypoallergenic CM products.展开更多
Mastitis is a complex, multifactorial disease. Pathogens, cows and farmers （via management） all play a role. It is costly and annoying for the farmer and threatens the image of the entire dairy industry. Prevention ...Mastitis is a complex, multifactorial disease. Pathogens, cows and farmers （via management） all play a role. It is costly and annoying for the farmer and threatens the image of the entire dairy industry. Prevention and control of mastitis is based on multiple principles that have been known for a long time. To implement them successfully, they should be put forward by a motivated and motivating advisor that transfers the existing knowledge to the farmer. When the changes are data-driven, applied by an encouraged farmer through a farm-specific implementation, prevention and control of mastitis will be successful and result in happy cows, happy farmers, happy advisors, happy consumers, and a happy industry. Nationwide projects focussing on communication and transfer of existing knowledge in prevention and control are very helpful in reaching high numbers of farmers and advisors and harmonizing the message brought by different parties. This paper gives an overview of multifactorial approach of mastitis management and prevention with a focus on milking, bedding and data-analysis.展开更多
Several in vitro fermentation studies had demonstrated the efficacy of Mootral, a patent-pending natural feed supplement, in reducing methane gas production. In order to test the supplement’s application in a commerc...Several in vitro fermentation studies had demonstrated the efficacy of Mootral, a patent-pending natural feed supplement, in reducing methane gas production. In order to test the supplement’s application in a commercial farm, Jersey (n = 121) and Holstein-Friesian (HF, n = 275) lactating cows received 500 g of pellets containing 3% Mootral powder for 12 weeks. Their enteric methane gas production was monitored using a hand-held laser methane detector. During 7 weeks of pre-Mootral supplementation period, dry matter intake (DMI), milk yield and milk quality (fat, protein, urea, pH, bulk tank somatic cell count (BTSCC)) were monitored for both herds and continued during 12 weeks of Mootral supplementation (Mootral period), and 4 weeks after withdrawal of Mootral (post-Mootral period). Feed samples were analysed during each period, and feed efficiencies (FE) for each herd were calculated. Compared to the baseline, the methane gas produced by the Jersey and HF cows during the Mootral period were lower by 38.3% and 20.7% (p < 0.05), respectively. DMI for Jerseys were greatest during the pre-Mootral period (p < 0.05), while no difference was recorded for the HF cows. Milk yield increased significantly (p < 0.05) for both herds during Mootral supplementation. FE increased significantly for the Jersey herd during the Mootral and post-Mootral periods (p < 0.05). Statistically significant changes were detected for urea in both herds, and BTSCC for HF cows, but these did not adversely affect milk quality. Results demonstrated Mootral reduces enteric methane production in lactating cows while increasing milk yield without affecting milk quality.展开更多
The aim of this study was to investigate the effect of duodenal infusion of soybean small peptides(SSP) on mammary uptake of amino acids(AA).Eight Chinese Saanen goats with duodenal fistulae and catheters were used in...The aim of this study was to investigate the effect of duodenal infusion of soybean small peptides(SSP) on mammary uptake of amino acids(AA).Eight Chinese Saanen goats with duodenal fistulae and catheters were used in a crossover design trial.Goats were infused with 0,60,120,180 g/d SSP.The experimental period lasted for 14 d.The results showed:1) milk protein yield and content were increased,with the increment in milk protein yield being significant(P【0.05).Milk fat yield and content were decreased with the increased amount of SSP infused(P【0.05).2) Mammary plasma flow was not changed(P】0.05) by SSP infusion though the average was slightly higher.Mammary plasma flow/milk yield was decreased by SSP infusion and there was significant difference between the 120 g/d treatment and the control(P【0.05).3) Compared with the control treatment,uptakes of most free amino acids were increased in the 60 and 120 g/d treatments,but decreased by the 180 g/d treatment.The uptakes of all peptide-bound essential amino acids(PB-EAA) were increased except for PB-Ile.Uptake of PB-Val,PB-Leu, PB-Phe,PB-Thr,PB-Met and PB-Lys was highest in the 120 g/d treatment.Among the peptide-bound nonessential amino acids(PB-NEAA),uptake of PB-Ser,PB-Tyr,and PB-Pro was increased(P【0.05) while that of PB-Gly was decreased(P】0.05).4) With the exception of Lys,secretion of all essential AA(EAA) was increased by SSP infusion from 0-120 g/d(P【0.05),while in the 180 g/d treatment the increase was not significant and was lower than that in the 120 g/d treatment.5) The expression of APN was increased by SSP;in the 60,120,180 g/d treatments expression was 13.55-,18.69-,and 10.01-fold over that of the controls.Conclusion:SSP might be used as substrates for milk protein synthesis by mammary gland,and can increase synthesis and secretion of milk protein.There was reason to believe that uptake and use of AA was either saturated or inhibited at high levels of infusion of SSP.Increased APN expression with infusion of SSP related to mammary up展开更多
Over the last several hundred years,donkeys have adapted to high-altitude conditions on the Tibetan Plateau.Interestingly,the kiang,a closely related equid species,also inhabits this region.Previous reports have demon...Over the last several hundred years,donkeys have adapted to high-altitude conditions on the Tibetan Plateau.Interestingly,the kiang,a closely related equid species,also inhabits this region.Previous reports have demonstrated the importance of specific genes and adaptive introgression in divergent lineages for adaptation to hypoxic conditions on the Tibetan Plateau.Here,we assessed whether donkeys and kiangs adapted to the Tibetan Plateau via the same or different biological pathways and whether adaptive introgression has occurred.We assembled a de novo genome from a kiang individual and analyzed the genomes of five kiangs and 93 donkeys(including 24 from the Tibetan Plateau).Our analyses suggested the existence of a strong hard selective sweep at the EPAS1 locus in kiangs.In Tibetan donkeys,however,another gene,i.e.,EGLN1,was likely involved in their adaptation to high altitude.In addition,admixture analysis found no evidence for interspecific gene flow between kiangs and Tibetan donkeys.Our findings indicate that despite the short evolutionary time scale since the arrival of donkeys on the Tibetan Plateau,as well as the existence of a closely related species already adapted to hypoxia,Tibetan donkeys did not acquire adaptation via admixture but instead evolved adaptations via a different biological pathway.展开更多
Thirty Holstein Friesian cows with similar weight, age, calving number, lactating length, fat percentage, and same physiology condition were selected and randomly divided into 3 groups: group I, group II and group III...Thirty Holstein Friesian cows with similar weight, age, calving number, lactating length, fat percentage, and same physiology condition were selected and randomly divided into 3 groups: group I, group II and group III, 20 g and 40 g Cysteamine /(cow·day) was supplemented into the normal diet for group I and group II, respectively; group III was used as control. Results showed that, group I and group II produced 4.86 % and 6.88 % more milk than that of control (P<0.05); Meanwhile, FCM (3.5 % fat) of group I and group II was increased by 4.98 % (P<0.01) and 6.56 % (P<0.01). Change of the milk fat among the three groups were not significant(P<0.05). Average daily milk protein yield significantly was increased by 4.14 % and 2.76 % respectively (P<0.05), though the milk protein content was slightly reduced. Moreover, somatic cells of the cow in the three groups were in normal physiological range in this trial.展开更多
文摘Emerging evidence shows the trend of using safe and natural preservatives like bacteriocins in food processing.The increasing demand by the food industry to extend keeping quality and prevent spoilage of various food products has appealed for new preservatives and new methods of conservation.Further,to discover the novel spectrum of antimicrobial compounds that could effectively battle food-borne pathogens,bacteriocins have been intensively studied in the last few years.Recently,great attention has been paid to the application of lactic acid-bacterial bacteriocins targeting food spoilage-causing or pathogenic microorganisms with no significant side effects.Different mechanisms of action like pore-formation,retarding cell-wall/nucleic acid/protein synthesis have been proposed and described for diverse bacteriocins.Therefore,the syntheses,purification of bacteriocins in addition to their applications as antimicrobial and preservative agents in food processing are reviewed in detail.The review will also discuss the preservative effect of bacteriocins and their combinations having multiple modes of action(hurdle approach)to reduce the microbial load as well as antimicrobial resistance.
基金Supported by Project of National Center of Technology Innovation for Dairy"Study on the Key Technologies of Microplastics Detection for New Pollutants in Dairy Ingredient Water"(2023-KFKT-24).
文摘As a new type of environmental pollutants,microplastics have gradually attracted people s attention.A large number of plastics discharged into the environment by human beings are constantly aging and breaking,and finally become microplastics.Microplastics can adsorb pollutants in the environment,and their components have certain toxicity,which can cause different degrees of harm to organisms.Due to the structural characteristics of microplastic particles,such as small particle size,large specific surface area,and their distribution in different environmental media,it is very difficult to accurately detect microplastics.Reliable collection and detection methods are the key to the study of environmental behavior of microplastics.In this study,the collection and detection methods of microplastics in the environment were reviewed,and the development direction of microplastics detection technology in the future was prospected.This study has a certain reference value for the related research and the prevention and treatment of micro-plastic pollution.
文摘The present study here establishes a complete and effective method for isolating,purifying and identifying extracellular and intracellular peptides,and also describes the characters and bioactivities of peptides from fermented casein with Lactobacillus helveticus.Intracellular peptides are much larger in quantity and more complex in composition than extracellular peptides,between which the correlation reveals proteolytic and metabolic mechanisms.In addition,totally 241 different peptide sequences were identified by Nano LC–MS/MS from casein(212)and Lactobacillus helveticus proteins(29).These casein-derived peptides mostly originated from-casein,followed byS1-casein,-casein,andS2-casein,and came from extracell(69)and intracell(143),in which common peptides have a total of 27.Forty-four of the identified peptides were previously described as bioactive,including angiotensinconverting enzyme(ACE)-inhibitory,antioxidant,immunomodulating,antimicrobial,DPP-IV inhibitory,antiamnesic and anticancer effects and so on.Thirteen peptides with the potential of some biological activities are obtained,which were described in previous studies.A total of 47 novel peptides of 5 to 26 amino acids that were not disclosed were obtained.The new sources of natural bioactive peptides may have the very high application value as potential new peptide drugs for treatment human diseases.The product peptide DELQDKIHPF found in both extracell and intracell was quantitatively analyzed using the MRM mode of UPLC-U3Q,23.1 and 9.76 ng/mL,respectively.The quantitative analysis of the potential bioactive peptide may also advance the production of peptide products in the future.
基金This study was supported by the Distinguished Young Foundation of Heilongjiang Province of China(JQ2020C006)Natural Science Foundation of Heilongjiang Province of China(Grant No.C2018022)+1 种基金Academic Backbone Plan of Northeast Agricultural University(Grant No.18XG27)“Characteristic Probiotics and New Fermented Food”Team in Northeast Agricultural University.
文摘Pea(Pisum sativum L.)is an important source of plant proteins.However,the use of pea flour as a food ingredient is greatly limited due to its strong beany flavor.In this work,we investigated the effects of Lactobacillus rhamnosus L08(L.rhamnosus L08)fermentation on the physicochemical characteristics,amino acids composition and volatile flavor compounds of pea flour.We found that L.rhamnosus L08 had the probiotic potential of utilizing pea flour as fermentation substrate.L.rhamnosus L08 fermentation significantly increased the content of most amino acids,and total amino acid content increased from 222.18 mg/g at 0 h to 262.35 mg/g at 6 h.A total of 44 volatile compounds were identified in pea flour.L.rhamnosus L08 fermentation increased the variety of acids and esters,while reduced the unpleasant flavor such as nonanal,decanal,octanal,1-hexanol and 2-ethyl-1-hexanol.The emulsifying stability and foam stability of pea flour were slightly enhanced during fermentation.Our results illustrate that lactic acid bacteria fermentation is a promising approach to eliminate undesirable aroma of pea flour.Moreover,this study provides theoretical support for the application of peas as high-quality protein source.
文摘The antioxidative,antimicrobial,and anti-inflammatory properties of fermented sheep milk with L.fermentum (KGL4),as well as the generation of antioxidative and antimicrobial peptides,are evaluated in the study.Antioxidative and antibacterial activities in sheep milk fermented with KGL4 increased with incubation hours,along with varied antioxidative properties (ABTS assay:35.12%,hydroxyl free radical scavenging assay:29.12%,superoxide free radical scavenging activity:36.38%).Antimicrobial activity of fermented sheep milk against E.faecalis (19 mm),S.typhimurium (15.67 mm),B.cereus (14 mm),and E.coli (13 mm) was also observed.Furthermore,after 48 h,the KGL4 showed maximum proteolysis (10.40 mg/ml) at 2.5% rate of addition sheep milk.The antioxidative and antimicrobial activities of fermented sheep milk fractions (3 kDa and 10 kDa permeates and retentates) were also investigated.The highest ABTS activity (26.90%) was found in 10 kDa permeate,whereas the 3 kDa retentate had higher hydroxyl free radical scavenging activity (69.20%) and 3 kDa permeate showed maximum superoxide free radical scavenging activity (32.85%).The 10 kDa retentate had shown maximum antimicrobial activity against S.typhimurium (13.67 mm) and E.faecalis (17.00 mm).Proteins spotted on 2D gel electrophoresis of KGL4 were varied from 10 to 70 kDa.RP-LC/MS was used to identify 5 novel peptide sequences from 2-D gel spots.Searches in the BIOPEP database confirmed the antioxidative and antimicrobial effects of the novel fermented sheep milk peptides.Fermented sheep milk with KGL4 (SMKGL4) significantly reduced excessive TNF-α,IL-6,& IL-1β production in LPS-activated RAW 264.7 cells.
基金the National Key R&D Program of China(Grant Number:2018YFC1604302-03).
文摘Cow milk allergy is a major cause of food hypersensitivity in infants and children.However,to the best of our knowledge,there has been minimal research on the antigenicity of cow milk(CM).As it is currently unknown if enzymatically hydrolyzed cow milk(HM)induces severe immunogenic responses,the potential allergenicity of HM was systematically evaluated in this work.HM effectively attenuated symptoms of weight loss and diarrhea,suppressed levels of mast cell tryptase,and relieved allergic inflammation of the intestine.Moreover,HM reduced the B220+cell count in mouse blood.In addition,in vitro studies demonstrated that gastrointestinal digestion of HM was not resistant to pepsin or trypsin.Thus,HM effectively alleviated allergic reactions and exhibited lower potential allergenicity.These results provide practical information for the future development of hypoallergenic CM products.
文摘Mastitis is a complex, multifactorial disease. Pathogens, cows and farmers （via management） all play a role. It is costly and annoying for the farmer and threatens the image of the entire dairy industry. Prevention and control of mastitis is based on multiple principles that have been known for a long time. To implement them successfully, they should be put forward by a motivated and motivating advisor that transfers the existing knowledge to the farmer. When the changes are data-driven, applied by an encouraged farmer through a farm-specific implementation, prevention and control of mastitis will be successful and result in happy cows, happy farmers, happy advisors, happy consumers, and a happy industry. Nationwide projects focussing on communication and transfer of existing knowledge in prevention and control are very helpful in reaching high numbers of farmers and advisors and harmonizing the message brought by different parties. This paper gives an overview of multifactorial approach of mastitis management and prevention with a focus on milking, bedding and data-analysis.
文摘Several in vitro fermentation studies had demonstrated the efficacy of Mootral, a patent-pending natural feed supplement, in reducing methane gas production. In order to test the supplement’s application in a commercial farm, Jersey (n = 121) and Holstein-Friesian (HF, n = 275) lactating cows received 500 g of pellets containing 3% Mootral powder for 12 weeks. Their enteric methane gas production was monitored using a hand-held laser methane detector. During 7 weeks of pre-Mootral supplementation period, dry matter intake (DMI), milk yield and milk quality (fat, protein, urea, pH, bulk tank somatic cell count (BTSCC)) were monitored for both herds and continued during 12 weeks of Mootral supplementation (Mootral period), and 4 weeks after withdrawal of Mootral (post-Mootral period). Feed samples were analysed during each period, and feed efficiencies (FE) for each herd were calculated. Compared to the baseline, the methane gas produced by the Jersey and HF cows during the Mootral period were lower by 38.3% and 20.7% (p < 0.05), respectively. DMI for Jerseys were greatest during the pre-Mootral period (p < 0.05), while no difference was recorded for the HF cows. Milk yield increased significantly (p < 0.05) for both herds during Mootral supplementation. FE increased significantly for the Jersey herd during the Mootral and post-Mootral periods (p < 0.05). Statistically significant changes were detected for urea in both herds, and BTSCC for HF cows, but these did not adversely affect milk quality. Results demonstrated Mootral reduces enteric methane production in lactating cows while increasing milk yield without affecting milk quality.
文摘The aim of this study was to investigate the effect of duodenal infusion of soybean small peptides(SSP) on mammary uptake of amino acids(AA).Eight Chinese Saanen goats with duodenal fistulae and catheters were used in a crossover design trial.Goats were infused with 0,60,120,180 g/d SSP.The experimental period lasted for 14 d.The results showed:1) milk protein yield and content were increased,with the increment in milk protein yield being significant(P【0.05).Milk fat yield and content were decreased with the increased amount of SSP infused(P【0.05).2) Mammary plasma flow was not changed(P】0.05) by SSP infusion though the average was slightly higher.Mammary plasma flow/milk yield was decreased by SSP infusion and there was significant difference between the 120 g/d treatment and the control(P【0.05).3) Compared with the control treatment,uptakes of most free amino acids were increased in the 60 and 120 g/d treatments,but decreased by the 180 g/d treatment.The uptakes of all peptide-bound essential amino acids(PB-EAA) were increased except for PB-Ile.Uptake of PB-Val,PB-Leu, PB-Phe,PB-Thr,PB-Met and PB-Lys was highest in the 120 g/d treatment.Among the peptide-bound nonessential amino acids(PB-NEAA),uptake of PB-Ser,PB-Tyr,and PB-Pro was increased(P【0.05) while that of PB-Gly was decreased(P】0.05).4) With the exception of Lys,secretion of all essential AA(EAA) was increased by SSP infusion from 0-120 g/d(P【0.05),while in the 180 g/d treatment the increase was not significant and was lower than that in the 120 g/d treatment.5) The expression of APN was increased by SSP;in the 60,120,180 g/d treatments expression was 13.55-,18.69-,and 10.01-fold over that of the controls.Conclusion:SSP might be used as substrates for milk protein synthesis by mammary gland,and can increase synthesis and secretion of milk protein.There was reason to believe that uptake and use of AA was either saturated or inhibited at high levels of infusion of SSP.Increased APN expression with infusion of SSP related to mammary up
基金supported by the National Natural Science Foundation of China (31621062)Strategic Priority Research Program of the Chinese Academy of Sciences (XDA2004010302)+4 种基金Second Tibetan Plateau Scientific Expedition and Research (STEP)Program (2019QZKK05010703)supported by the National Natural Science Foundation of China (91731304, 31822048)Strategic Priority Research Program of the Chinese Academy of Sciences (XDB13020600)Qinghai Department of Science and Technology Major ProjectState Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan,Yunnan University(2018KF001)supported by the Animal Branch of the Germplasm Bank of Wild Species,Chinese Academy of Sciences (Large Research Infrastructure Funding)
文摘Over the last several hundred years,donkeys have adapted to high-altitude conditions on the Tibetan Plateau.Interestingly,the kiang,a closely related equid species,also inhabits this region.Previous reports have demonstrated the importance of specific genes and adaptive introgression in divergent lineages for adaptation to hypoxic conditions on the Tibetan Plateau.Here,we assessed whether donkeys and kiangs adapted to the Tibetan Plateau via the same or different biological pathways and whether adaptive introgression has occurred.We assembled a de novo genome from a kiang individual and analyzed the genomes of five kiangs and 93 donkeys(including 24 from the Tibetan Plateau).Our analyses suggested the existence of a strong hard selective sweep at the EPAS1 locus in kiangs.In Tibetan donkeys,however,another gene,i.e.,EGLN1,was likely involved in their adaptation to high altitude.In addition,admixture analysis found no evidence for interspecific gene flow between kiangs and Tibetan donkeys.Our findings indicate that despite the short evolutionary time scale since the arrival of donkeys on the Tibetan Plateau,as well as the existence of a closely related species already adapted to hypoxia,Tibetan donkeys did not acquire adaptation via admixture but instead evolved adaptations via a different biological pathway.
文摘Thirty Holstein Friesian cows with similar weight, age, calving number, lactating length, fat percentage, and same physiology condition were selected and randomly divided into 3 groups: group I, group II and group III, 20 g and 40 g Cysteamine /(cow·day) was supplemented into the normal diet for group I and group II, respectively; group III was used as control. Results showed that, group I and group II produced 4.86 % and 6.88 % more milk than that of control (P<0.05); Meanwhile, FCM (3.5 % fat) of group I and group II was increased by 4.98 % (P<0.01) and 6.56 % (P<0.01). Change of the milk fat among the three groups were not significant(P<0.05). Average daily milk protein yield significantly was increased by 4.14 % and 2.76 % respectively (P<0.05), though the milk protein content was slightly reduced. Moreover, somatic cells of the cow in the three groups were in normal physiological range in this trial.
