Background: Residual feed intake(RFI) is an inheritable measure of feed efficiency that is independent on level of production. However, physiological and metabolic mechanisms underlying divergent RFI are not fully elu...Background: Residual feed intake(RFI) is an inheritable measure of feed efficiency that is independent on level of production. However, physiological and metabolic mechanisms underlying divergent RFI are not fully elucidated.This study was conducted to investigate dietary nitrogen(N) partitioning and microbial protein synthesis in lactating dairy cows divergent in phenotypic RFI.Results: Thirty Holstein dairy cows(milk yield = 35.3 ± 4.71 kg/d;milk protein yield = 1.18 ± 0.13 kg/d;mean ± standard deviation) were selected for the experiment to derive RFI. After the RFI measurement period of 50 d, the 10 lowest RFI cows and 8 highest RFI cows were selected. The low RFI cows had lower dry matter intake(DMI, P < 0.05) than the high RFI cows, but they produced similar energy-corrected milk. The ratios of milk to DMI(1.41 vs. 1.24, P < 0.01) and energy-corrected milk to DMI(1.48 vs. 1.36, P < 0.01) were greater in low RFI cows than those in the high RFI cows. The low RFI cows had lower milk urea nitrogen than that in the high RFI cows(P = 0.05). Apparent digestibility of nutrients did not differ between two groups(P > 0.10). Compared with high RFI animals, the low RFI cows had a lower retention of N(5.72 vs. 51.4 g/d, P < 0.05) and a higher partition of feed N to milk N(29.7% vs. 26.5%, P < 0.05).Conclusions: The results suggest that differences in N partition, synthesis of microbial protein, and utilization of metabolizable protein could be part of the mechanisms associated with variance in the RFI.展开更多
Objective To investigate the 23 bp and 12 bp insertion/deletion(indel)mutations within the bovine prion protein(PRNP)gene in Chinese dairy cows,and to detect the associations of two indel mutations with BSE susceptibi...Objective To investigate the 23 bp and 12 bp insertion/deletion(indel)mutations within the bovine prion protein(PRNP)gene in Chinese dairy cows,and to detect the associations of two indel mutations with BSE susceptibility and milk performance.Methods Based on bovine PRNP gene sequence,two pairs of primers for testing the 23 bp and 12 bp indel mutations were designed.The PCR amplification and agarose electrophoresis were carried out to distinguish the different genotypes within the mutations.Moreover,based on previous data from other cattle breeds and present genotypic and allelic frequencies of two indels mutations in this study,the corrections between the two indel mutations and BSE susceptibility were tested,as well as the relationships between the mutations and milk performance traits were analyzed in this study based on the statistical analyses.Results In the analyzed Chinese Holstein population,the frequencies of two"del"alleles in 23 bp and 12 bp indel muations were more frequent.The frequency of haplotype of 23del-12del was higher than those of 23del-12ins and 23ins-12del.From the estimated r2and D’values,two indel polymorphisms were linked strongly in the Holstein population(D’=57.5%,r2=0.257).Compared with the BSE-affected cattle populations from the reported data,the significant differences of genotypic and allelic frequencies were found among present Holstein and some BSE-affected populations(P<0.05 or P<0.01).Similarly,there were significant frequency distribution differences of genotypes and alleles among Chinese Holstein and several previous reported healthy dairy cattle(P<0.05 or P<0.01).Moreover,association of genotype and combined genotypes of two indel polymorphisms with milk performance and resistant mastitis traits were analyzed in Holstein population,but no significant differences were found(P>0.05).Conclusions These observations revealed that the influence of two indel mutations within the bovine PRNP gene on BSE depended on the breed and they did not affect the milk production traits,which layed the foundation for future selection of resistant animals,and for improving health conditions for dairy breeding against BSE in China.展开更多
[Objective] This study aimed to prepare dairy cow anti-S100A12 antisem and develop a highly effective and sensitive immunological detection reagent for further investigation of the functions of dairy cow S100A12. [Met...[Objective] This study aimed to prepare dairy cow anti-S100A12 antisem and develop a highly effective and sensitive immunological detection reagent for further investigation of the functions of dairy cow S100A12. [Method] Purified S100A12 protein was respectively emulsified with Freund's complete adjuvant and Freund's incomplete adjuvant as the antigen for immunizing New Zealand white rabbits to prepare the polyclonal antisera. The titer was detected using agar double diffusion assay and indirect enzyme-linked immunoserbent assay (ELISA) and the specificity was determined with Western Blot. [ Result ] The titer of anti- S100A12 antisera was 1: 8 as determined by agar double diffusion assay and over 1:409 600 by ELISA. Western Blot result showed that the polyclonal antisera could be specifically combined with S100A12 protein. [ Conclusion] The results indicated that anti-S100A12 polyclonal antibody with high fiter and high specificity was successfully obtained, which provided a novel tool for further investigation of the functions of S100A12 gene.展开更多
Four early lactating Holstein cows were used to study the effect of live yeast (LY, Actisaf®CNCM I-4407, Lesaffre Feed Additives, Marcq en Baroeul, France) supplementation on diet digestive utilization of dair...Four early lactating Holstein cows were used to study the effect of live yeast (LY, Actisaf®CNCM I-4407, Lesaffre Feed Additives, Marcq en Baroeul, France) supplementation on diet digestive utilization of dairy cows receiving concentrated corn silage-based diets with two rumen-degradable protein (RDP) levels. For a 33 d period, cows were fed a total mixed ration (TMR) containing an adequate level (AL) of RDP or a low level (LL, 30% below AL) by using soybean meal or tanned soybean meal, respectively: for 21 d with no LY addition followed by 12 d during which LY was added to the diet. The pH and redox potential (Eh) were recorded and ruminal fluid samples were collected over 3 consecutive days. Feces were collected individually over 48 h and individual dry matter intake (DMI) was measured for determining apparent nutrient digestibility. The effective degradability of individual feed ingredients composing both diets was evaluated with nylon bags technique. Structure of the ruminal bacterial community was studied and diversity index was calculated. Digestibility of organic matter (OM) and crude protein (CP) were lower for LL than those for AL. With LY, digestibility of OM and CP was increased: +2.4 and +0.8 points, for AL, and +3.7 and +5.9 points for LL, respectively. Live yeast reduced dietary N ruminal degradation with both AL and LL. Ruminal pH and Eh were lower with AL compared to LL: 5.95 and –167 mV vs. 6.13 and –144 mV. Live yeast increased ruminal total volatile fatty acids (VFA) (+8.6%), C2 (+10%), and C4 (+35%) contents for LL and decreased that of C3 (?9.8%) for AL. Neither the structure of bacterial populations of the rumen nor the diversity index (Shannon) was altered by treatments. Those results suggested a specific interest in using LY in RDP deficient diets for early lactating cows.展开更多
One hundred and three Hereford × Angus crossbred, spring-calving cows were used to determine the influence of early weaning performance of their male progeny and the need for cowherd winter supplementation. Treat...One hundred and three Hereford × Angus crossbred, spring-calving cows were used to determine the influence of early weaning performance of their male progeny and the need for cowherd winter supplementation. Treatments were early weaned (EW;115-d of age) and normal weaned calves (NW;220-d of age). Both intact and castrated male progeny were randomly allotted to early and normal weaning calf management treatments. Following summer grazing and weaning protocols, cows within each weaning group were randomly assigned to receive winter supplementation treatments of LOW (1.26 kg/hd/d) or HIGH (1.81 kg/hd/d) amounts of a protein supplement containing 450 g/kg CP (DM basis). Cows whose calves were weaned early gained more BW and BCS (P P P P = 0.04) BCS but similar (P = 0.74) BW when compared with cows with normally weaned calves that received 100% of their supplement (NWHIGH). Early weaning has the potential to reduce the amount of supplement required during the winter grazing period.展开更多
The experiment was designed to determine the effect of protected lysine (Lys) and methionine (Met) supply on milk protein profile in grazing dairy cows specifically in the caseins (CNs) and α-lactalbumin fractions. T...The experiment was designed to determine the effect of protected lysine (Lys) and methionine (Met) supply on milk protein profile in grazing dairy cows specifically in the caseins (CNs) and α-lactalbumin fractions. Twelve multiparous mid lactation Holstein cows producing 24 (±4.76) kg of milk were assigned to one of two treatments (six cows per treatment) during an experimental period of 21 days. In the control (C) group, cows grazed a Pennisetum clandestinum pasture and were supplemented with a commercial concentrate according to milk production. In the Met-Lys treatment, cows received the same ration supplemented with protected Lys and Met. Milk yield and composition and milk protein profile were measured at the start and the end (21st day) of the experimental period. The Tricine-SDS-PAGE and the Gel-Quant Express Analysis (Invitrogen) software were used to determine milk protein composition. Statistical analysis was performed using the SAS’s PROC MIXED procedure through a mixed model that included the animal as a random effect and the treatments as a fixed effect adjusted by covariables. Milk production averaged 23.7 (±2.0) kg cow-1 day-1 without differences between treatments (P P -1 day-1) compared to C (24.2 kg cow-1 day-1). Milk protein content (g/kg) did not differ (C = 30.4;Met-Lys = 31.1) and lactose content tended (P P β-CN also increased (P < 0.05) after protected aminoacid supply (C = 9.58;Met-Lys = 10.35). It can be concluded that milk protein composition was improved by protected Lys-Met supply without altering other compositional parameters of milk composition. Milk nutritional quality and its potential yield for cheese-making were positively enhanced.展开更多
The probiotic Bacillus subtilis (B. subtilis) was widely applied in animal production as feed additive. Lysine (Lys) and methionine (Met) were the two most important limiting amino acids in livestock animal feed...The probiotic Bacillus subtilis (B. subtilis) was widely applied in animal production as feed additive. Lysine (Lys) and methionine (Met) were the two most important limiting amino acids in livestock animal feed. Raising Lys and Met contents in B. subtilis would provide better effects for animal production and save Lys and Met supplements. We still didn't know whether Lys- rich and Met-rich protein genes from plants could be transfected into B. subtilis and expressed at a high level so as to improve animal production, such as milk production as an additional diet. The Lys-rich protein gene (Cflr) and Met-rich 10 ku-δ Zein were cloned from pepper anther and maize endosperm, respectively. Then they were constructed into plasmids individually and successfully cotransfected into B. subtilis. Upon IPTG induction, mRNAs and protein expressions could be observed. Lys and Met contents in the fermentation broth were raised by 65.92% and 46.39%, respectively. After feeding 200 g and 400 g· cow^-1· d^-1, transgenic B. subtilis fermentation broth, the milk yield, milk protein and milk fat contents all significantly increased. The Lys-rich protein gene (Cflr) and Met-rich 10 ku-δ Zein were successfully transfected into B. subtilis. Contents of Lys and Met in the transgenic B. subalis obviously raised and the fermentation broth of the transgenic bacteria could effectively improve milk yield and quality.展开更多
Milk is related to many gastrointestinal disorders from the cradle to the grave due to the many milk ingredients that can trigger gastrointestinal discomfort and disorders.Cow’s milk protein allergy(CMPA)is the most ...Milk is related to many gastrointestinal disorders from the cradle to the grave due to the many milk ingredients that can trigger gastrointestinal discomfort and disorders.Cow’s milk protein allergy(CMPA)is the most common food allergy,especially in infancy and childhood,which may persist into adulthood.There are three main types of CMPA;immunoglobulin E(IgE)-mediated CMPA,non-IgEmediated CMPA,and mixed type.CMPA appears before the first birthday in almost all cases.Symptoms may start even during the neonatal period and can be severe enough to simulate neonatal sepsis.CMPA(often non-IgE mediated)can present with symptoms of gastroesophageal reflux,eosinophilic esophagitis,hemorrhagic gastritis,food protein-induced protein-losing enteropathy,and food protein-induced enterocolitis syndrome.Most CMPAs are benign and outgrown during childhood.CMPA is not as common in adults as in children,but when present,it is usually severe with a protracted course.Lactose intolerance is a prevalent condition characterized by the development of many symptoms related to the consumption of foods containing lactose.Lactose intolerance has four typical types:Developmental,congenital,primary,and secondary.Lactose intolerance and CMPA may be the underlying pathophysiologic mechanisms for many functional gastrointestinal disorders in children and adults.They are also common in inflammatory bowel diseases.Milk consumption may have preventive or promoter effects on cancer development.Milk may also become a source of microbial infection in humans,causing a wide array of diseases,and may help increase the prevalence of antimicrobial resistance.This editorial summarizes the common milk-related disorders and their symptoms from childhood to adulthood.展开更多
新生儿牛奶蛋白过敏(cow's milk protein allergy,CMPA)临床表现不典型,可导致多器官和系统受累,并且可能影响新生儿体格生长和中枢神经系统发育,造成机体功能障碍,还会增加其他家庭成员的焦虑和压力。由于缺乏特异性临床表现和诊...新生儿牛奶蛋白过敏(cow's milk protein allergy,CMPA)临床表现不典型,可导致多器官和系统受累,并且可能影响新生儿体格生长和中枢神经系统发育,造成机体功能障碍,还会增加其他家庭成员的焦虑和压力。由于缺乏特异性临床表现和诊断方法,新生儿CMPA的诊断和管理仍然是目前非常重要的临床挑战。为促进新生儿CMPA规范化诊治,由中华医学会儿科学分会新生儿学组、中华儿科杂志编辑委员会组织制定了《新生儿牛奶蛋白过敏诊断与管理专家共识(2023)》,该文对该共识新生儿CMPA饮食和营养管理部分重点内容进行介绍和解读。展开更多
目的探讨个体化营养干预对牛奶蛋白过敏(cow milk protein allergy,CMPA)患儿营养状况及生长发育的影响。方法选取2022年2月—2023年2月惠州市中心人民医院儿科收治的60例CMPA患儿作为研究对象。其中30例作为对照组给予游离氨基酸奶粉...目的探讨个体化营养干预对牛奶蛋白过敏(cow milk protein allergy,CMPA)患儿营养状况及生长发育的影响。方法选取2022年2月—2023年2月惠州市中心人民医院儿科收治的60例CMPA患儿作为研究对象。其中30例作为对照组给予游离氨基酸奶粉进行喂养,另外30例作为研究组给予个体化营养干预(包括游离氨基酸奶粉喂养、辅食回避、微量元素及维生素的合理补充)。干预6个月后,对比2组患儿生长发育指标(身高、体质量、头围)、营养指标(血红蛋白、白蛋白、转铁蛋白)、血清维生素D、钙、锌水平及干预疗效。结果干预后,研究组患儿的生长发育指标优于对照组,营养状况优于对照组,血清维生素D、钙、锌水平高于对照组(P<0.05)。研究组患儿的总有效率为100%,高于对照组的83.33%,差异有统计学意义(P<0.05)。结论对CMPA患儿给予个体化营养干预可以有效促进患儿生长发育,提升患儿营养状况,临床效果显著。展开更多
目的探索牛奶蛋白过敏(cow's milk protein allergy,CMPA)患儿肠道菌群及短链脂肪酸水平的变化,明确其在CMPA中的作用。方法纳入2019年8月—2020年8月在郑州大学附属儿童医院就诊的25例CMPA婴儿作为CMPA组,同时选取25例正常婴儿作...目的探索牛奶蛋白过敏(cow's milk protein allergy,CMPA)患儿肠道菌群及短链脂肪酸水平的变化,明确其在CMPA中的作用。方法纳入2019年8月—2020年8月在郑州大学附属儿童医院就诊的25例CMPA婴儿作为CMPA组,同时选取25例正常婴儿作为对照组。收集两组婴儿粪便200mg,采用16SrDNA高通量检测技术和液相色谱质谱联用技术分别检测肠道微生物组成及其代谢产物的变化,并将微生物多样性与代谢产物进行联合分析。结果与对照组相比,CMPA组患儿肠道菌群结构发生变化,且α-多样性显著增加(P<0.001)。与对照组相比,CMPA组患儿肠道内厚壁菌门、梭状芽孢杆菌目、拟杆菌丰度显著降低,而梭菌科、支原体科、鞘脂单胞菌科丰度显著增加(P<0.001)。代谢组学检测发现,与对照组相比,CMPA组菌群代谢产物乙酸、丁酸和异戊酸水平显著下降,并与短链脂肪酸产生菌粪杆菌属、罗氏菌属等丰度呈正相关(P<0.05)。结论CMPA患儿肠道内菌群结构发生改变,微生物多样性增加,短链脂肪酸水平降低,可能导致肠道炎症反应增加。展开更多
基金supported by grants from the National Natural Science Foundation of China(No.31872380)the China Agricultural Research System(Beijing,China No.CARS-36)
文摘Background: Residual feed intake(RFI) is an inheritable measure of feed efficiency that is independent on level of production. However, physiological and metabolic mechanisms underlying divergent RFI are not fully elucidated.This study was conducted to investigate dietary nitrogen(N) partitioning and microbial protein synthesis in lactating dairy cows divergent in phenotypic RFI.Results: Thirty Holstein dairy cows(milk yield = 35.3 ± 4.71 kg/d;milk protein yield = 1.18 ± 0.13 kg/d;mean ± standard deviation) were selected for the experiment to derive RFI. After the RFI measurement period of 50 d, the 10 lowest RFI cows and 8 highest RFI cows were selected. The low RFI cows had lower dry matter intake(DMI, P < 0.05) than the high RFI cows, but they produced similar energy-corrected milk. The ratios of milk to DMI(1.41 vs. 1.24, P < 0.01) and energy-corrected milk to DMI(1.48 vs. 1.36, P < 0.01) were greater in low RFI cows than those in the high RFI cows. The low RFI cows had lower milk urea nitrogen than that in the high RFI cows(P = 0.05). Apparent digestibility of nutrients did not differ between two groups(P > 0.10). Compared with high RFI animals, the low RFI cows had a lower retention of N(5.72 vs. 51.4 g/d, P < 0.05) and a higher partition of feed N to milk N(29.7% vs. 26.5%, P < 0.05).Conclusions: The results suggest that differences in N partition, synthesis of microbial protein, and utilization of metabolizable protein could be part of the mechanisms associated with variance in the RFI.
基金supported by the National Natural Science Foundation of China (Grant No. 31272408 30972080)+2 种基金the National 863 Program of China (Grant No. 2013AA102505)the Program of National Beef Cattle and yak Industrial Technology System (CARS-38)the Agricultural Science and Technology Innovation Projects of Shanxi Province (No. 2012NKC01-13).
文摘Objective To investigate the 23 bp and 12 bp insertion/deletion(indel)mutations within the bovine prion protein(PRNP)gene in Chinese dairy cows,and to detect the associations of two indel mutations with BSE susceptibility and milk performance.Methods Based on bovine PRNP gene sequence,two pairs of primers for testing the 23 bp and 12 bp indel mutations were designed.The PCR amplification and agarose electrophoresis were carried out to distinguish the different genotypes within the mutations.Moreover,based on previous data from other cattle breeds and present genotypic and allelic frequencies of two indels mutations in this study,the corrections between the two indel mutations and BSE susceptibility were tested,as well as the relationships between the mutations and milk performance traits were analyzed in this study based on the statistical analyses.Results In the analyzed Chinese Holstein population,the frequencies of two"del"alleles in 23 bp and 12 bp indel muations were more frequent.The frequency of haplotype of 23del-12del was higher than those of 23del-12ins and 23ins-12del.From the estimated r2and D’values,two indel polymorphisms were linked strongly in the Holstein population(D’=57.5%,r2=0.257).Compared with the BSE-affected cattle populations from the reported data,the significant differences of genotypic and allelic frequencies were found among present Holstein and some BSE-affected populations(P<0.05 or P<0.01).Similarly,there were significant frequency distribution differences of genotypes and alleles among Chinese Holstein and several previous reported healthy dairy cattle(P<0.05 or P<0.01).Moreover,association of genotype and combined genotypes of two indel polymorphisms with milk performance and resistant mastitis traits were analyzed in Holstein population,but no significant differences were found(P>0.05).Conclusions These observations revealed that the influence of two indel mutations within the bovine PRNP gene on BSE depended on the breed and they did not affect the milk production traits,which layed the foundation for future selection of resistant animals,and for improving health conditions for dairy breeding against BSE in China.
基金Supported by China Postdoctoral Science Foundation(20090451250)Youth Fund of Sichuan Provincial Department of Education(09ZB054)Program for Changjiang Scholars and Innovative Research Team in University of the Ministry of Education(IRT0848)
文摘[Objective] This study aimed to prepare dairy cow anti-S100A12 antisem and develop a highly effective and sensitive immunological detection reagent for further investigation of the functions of dairy cow S100A12. [Method] Purified S100A12 protein was respectively emulsified with Freund's complete adjuvant and Freund's incomplete adjuvant as the antigen for immunizing New Zealand white rabbits to prepare the polyclonal antisera. The titer was detected using agar double diffusion assay and indirect enzyme-linked immunoserbent assay (ELISA) and the specificity was determined with Western Blot. [ Result ] The titer of anti- S100A12 antisera was 1: 8 as determined by agar double diffusion assay and over 1:409 600 by ELISA. Western Blot result showed that the polyclonal antisera could be specifically combined with S100A12 protein. [ Conclusion] The results indicated that anti-S100A12 polyclonal antibody with high fiter and high specificity was successfully obtained, which provided a novel tool for further investigation of the functions of S100A12 gene.
文摘Four early lactating Holstein cows were used to study the effect of live yeast (LY, Actisaf®CNCM I-4407, Lesaffre Feed Additives, Marcq en Baroeul, France) supplementation on diet digestive utilization of dairy cows receiving concentrated corn silage-based diets with two rumen-degradable protein (RDP) levels. For a 33 d period, cows were fed a total mixed ration (TMR) containing an adequate level (AL) of RDP or a low level (LL, 30% below AL) by using soybean meal or tanned soybean meal, respectively: for 21 d with no LY addition followed by 12 d during which LY was added to the diet. The pH and redox potential (Eh) were recorded and ruminal fluid samples were collected over 3 consecutive days. Feces were collected individually over 48 h and individual dry matter intake (DMI) was measured for determining apparent nutrient digestibility. The effective degradability of individual feed ingredients composing both diets was evaluated with nylon bags technique. Structure of the ruminal bacterial community was studied and diversity index was calculated. Digestibility of organic matter (OM) and crude protein (CP) were lower for LL than those for AL. With LY, digestibility of OM and CP was increased: +2.4 and +0.8 points, for AL, and +3.7 and +5.9 points for LL, respectively. Live yeast reduced dietary N ruminal degradation with both AL and LL. Ruminal pH and Eh were lower with AL compared to LL: 5.95 and –167 mV vs. 6.13 and –144 mV. Live yeast increased ruminal total volatile fatty acids (VFA) (+8.6%), C2 (+10%), and C4 (+35%) contents for LL and decreased that of C3 (?9.8%) for AL. Neither the structure of bacterial populations of the rumen nor the diversity index (Shannon) was altered by treatments. Those results suggested a specific interest in using LY in RDP deficient diets for early lactating cows.
文摘One hundred and three Hereford × Angus crossbred, spring-calving cows were used to determine the influence of early weaning performance of their male progeny and the need for cowherd winter supplementation. Treatments were early weaned (EW;115-d of age) and normal weaned calves (NW;220-d of age). Both intact and castrated male progeny were randomly allotted to early and normal weaning calf management treatments. Following summer grazing and weaning protocols, cows within each weaning group were randomly assigned to receive winter supplementation treatments of LOW (1.26 kg/hd/d) or HIGH (1.81 kg/hd/d) amounts of a protein supplement containing 450 g/kg CP (DM basis). Cows whose calves were weaned early gained more BW and BCS (P P P P = 0.04) BCS but similar (P = 0.74) BW when compared with cows with normally weaned calves that received 100% of their supplement (NWHIGH). Early weaning has the potential to reduce the amount of supplement required during the winter grazing period.
文摘The experiment was designed to determine the effect of protected lysine (Lys) and methionine (Met) supply on milk protein profile in grazing dairy cows specifically in the caseins (CNs) and α-lactalbumin fractions. Twelve multiparous mid lactation Holstein cows producing 24 (±4.76) kg of milk were assigned to one of two treatments (six cows per treatment) during an experimental period of 21 days. In the control (C) group, cows grazed a Pennisetum clandestinum pasture and were supplemented with a commercial concentrate according to milk production. In the Met-Lys treatment, cows received the same ration supplemented with protected Lys and Met. Milk yield and composition and milk protein profile were measured at the start and the end (21st day) of the experimental period. The Tricine-SDS-PAGE and the Gel-Quant Express Analysis (Invitrogen) software were used to determine milk protein composition. Statistical analysis was performed using the SAS’s PROC MIXED procedure through a mixed model that included the animal as a random effect and the treatments as a fixed effect adjusted by covariables. Milk production averaged 23.7 (±2.0) kg cow-1 day-1 without differences between treatments (P P -1 day-1) compared to C (24.2 kg cow-1 day-1). Milk protein content (g/kg) did not differ (C = 30.4;Met-Lys = 31.1) and lactose content tended (P P β-CN also increased (P < 0.05) after protected aminoacid supply (C = 9.58;Met-Lys = 10.35). It can be concluded that milk protein composition was improved by protected Lys-Met supply without altering other compositional parameters of milk composition. Milk nutritional quality and its potential yield for cheese-making were positively enhanced.
基金Supported by High Technology Project of Ministry of Science and Technology of China(863 Project)(2013AA102504-03)Major Project of Applying Technology Research and Development of Heilongjiang Province(GA15B203)
文摘The probiotic Bacillus subtilis (B. subtilis) was widely applied in animal production as feed additive. Lysine (Lys) and methionine (Met) were the two most important limiting amino acids in livestock animal feed. Raising Lys and Met contents in B. subtilis would provide better effects for animal production and save Lys and Met supplements. We still didn't know whether Lys- rich and Met-rich protein genes from plants could be transfected into B. subtilis and expressed at a high level so as to improve animal production, such as milk production as an additional diet. The Lys-rich protein gene (Cflr) and Met-rich 10 ku-δ Zein were cloned from pepper anther and maize endosperm, respectively. Then they were constructed into plasmids individually and successfully cotransfected into B. subtilis. Upon IPTG induction, mRNAs and protein expressions could be observed. Lys and Met contents in the fermentation broth were raised by 65.92% and 46.39%, respectively. After feeding 200 g and 400 g· cow^-1· d^-1, transgenic B. subtilis fermentation broth, the milk yield, milk protein and milk fat contents all significantly increased. The Lys-rich protein gene (Cflr) and Met-rich 10 ku-δ Zein were successfully transfected into B. subtilis. Contents of Lys and Met in the transgenic B. subalis obviously raised and the fermentation broth of the transgenic bacteria could effectively improve milk yield and quality.
文摘Milk is related to many gastrointestinal disorders from the cradle to the grave due to the many milk ingredients that can trigger gastrointestinal discomfort and disorders.Cow’s milk protein allergy(CMPA)is the most common food allergy,especially in infancy and childhood,which may persist into adulthood.There are three main types of CMPA;immunoglobulin E(IgE)-mediated CMPA,non-IgEmediated CMPA,and mixed type.CMPA appears before the first birthday in almost all cases.Symptoms may start even during the neonatal period and can be severe enough to simulate neonatal sepsis.CMPA(often non-IgE mediated)can present with symptoms of gastroesophageal reflux,eosinophilic esophagitis,hemorrhagic gastritis,food protein-induced protein-losing enteropathy,and food protein-induced enterocolitis syndrome.Most CMPAs are benign and outgrown during childhood.CMPA is not as common in adults as in children,but when present,it is usually severe with a protracted course.Lactose intolerance is a prevalent condition characterized by the development of many symptoms related to the consumption of foods containing lactose.Lactose intolerance has four typical types:Developmental,congenital,primary,and secondary.Lactose intolerance and CMPA may be the underlying pathophysiologic mechanisms for many functional gastrointestinal disorders in children and adults.They are also common in inflammatory bowel diseases.Milk consumption may have preventive or promoter effects on cancer development.Milk may also become a source of microbial infection in humans,causing a wide array of diseases,and may help increase the prevalence of antimicrobial resistance.This editorial summarizes the common milk-related disorders and their symptoms from childhood to adulthood.
文摘目的:初步探讨孕期因素与婴儿牛奶蛋白过敏的关系。方法:数据来自一项“中国儿童对牛奶蛋白过敏的遗传易感性研究”的子队列,包括2020年3月1日至12月31日在北京大学人民医院出生的婴儿,根据随访至1岁时有无牛奶蛋白过敏(cow’s milk protein allergy,CMPA),分为病例组(CMPA组)和对照组。回顾性收集婴儿及其母亲孕前和孕期的临床资料,分析孕期多因素与婴儿牛奶蛋白过敏的相关性。结果:共纳入278例婴儿,CMPA患儿52例,对照组226例;男性婴儿143例,女性婴儿135例,其中男性婴儿在CMPA组比例(69.2%)高于对照组(47.3%),差异有统计学意义(P=0.004);CMPA患儿和对照组在出生体质量、出生胎龄、低出生体重儿、早产、脐带绕颈、新生儿窒息分布上差异无统计学意义(P>0.05)。母亲孕期合并免疫性疾病、贫血者以及孕期存在抗生素暴露者在CMPA组比例均高于对照组,两组之间差异有统计学意义(P<0.05);其他妊娠期合并症,如子痫/子痫前期、慢性高血压/妊娠期高血压、糖尿病/妊娠期糖尿病、甲状腺疾病等在两组分布差异无统计学意义(P>0.05)。CMPA组与对照组孕期多项血常规指标总体分布差异无统计学意义(P>0.05)。多因素Logistic回归分析发现男性婴儿、母亲妊娠合并免疫性疾病、妊娠合并贫血以及孕期抗生素暴露是CMPA发生的独立危险因素。结论:男性婴儿、母亲妊娠合并免疫性疾病、妊娠合并贫血以及孕期抗生素暴露是CMPA发生的独立危险因素。
文摘新生儿牛奶蛋白过敏(cow's milk protein allergy,CMPA)临床表现不典型,可导致多器官和系统受累,并且可能影响新生儿体格生长和中枢神经系统发育,造成机体功能障碍,还会增加其他家庭成员的焦虑和压力。由于缺乏特异性临床表现和诊断方法,新生儿CMPA的诊断和管理仍然是目前非常重要的临床挑战。为促进新生儿CMPA规范化诊治,由中华医学会儿科学分会新生儿学组、中华儿科杂志编辑委员会组织制定了《新生儿牛奶蛋白过敏诊断与管理专家共识(2023)》,该文对该共识新生儿CMPA饮食和营养管理部分重点内容进行介绍和解读。
文摘目的探讨个体化营养干预对牛奶蛋白过敏(cow milk protein allergy,CMPA)患儿营养状况及生长发育的影响。方法选取2022年2月—2023年2月惠州市中心人民医院儿科收治的60例CMPA患儿作为研究对象。其中30例作为对照组给予游离氨基酸奶粉进行喂养,另外30例作为研究组给予个体化营养干预(包括游离氨基酸奶粉喂养、辅食回避、微量元素及维生素的合理补充)。干预6个月后,对比2组患儿生长发育指标(身高、体质量、头围)、营养指标(血红蛋白、白蛋白、转铁蛋白)、血清维生素D、钙、锌水平及干预疗效。结果干预后,研究组患儿的生长发育指标优于对照组,营养状况优于对照组,血清维生素D、钙、锌水平高于对照组(P<0.05)。研究组患儿的总有效率为100%,高于对照组的83.33%,差异有统计学意义(P<0.05)。结论对CMPA患儿给予个体化营养干预可以有效促进患儿生长发育,提升患儿营养状况,临床效果显著。
文摘目的探索牛奶蛋白过敏(cow's milk protein allergy,CMPA)患儿肠道菌群及短链脂肪酸水平的变化,明确其在CMPA中的作用。方法纳入2019年8月—2020年8月在郑州大学附属儿童医院就诊的25例CMPA婴儿作为CMPA组,同时选取25例正常婴儿作为对照组。收集两组婴儿粪便200mg,采用16SrDNA高通量检测技术和液相色谱质谱联用技术分别检测肠道微生物组成及其代谢产物的变化,并将微生物多样性与代谢产物进行联合分析。结果与对照组相比,CMPA组患儿肠道菌群结构发生变化,且α-多样性显著增加(P<0.001)。与对照组相比,CMPA组患儿肠道内厚壁菌门、梭状芽孢杆菌目、拟杆菌丰度显著降低,而梭菌科、支原体科、鞘脂单胞菌科丰度显著增加(P<0.001)。代谢组学检测发现,与对照组相比,CMPA组菌群代谢产物乙酸、丁酸和异戊酸水平显著下降,并与短链脂肪酸产生菌粪杆菌属、罗氏菌属等丰度呈正相关(P<0.05)。结论CMPA患儿肠道内菌群结构发生改变,微生物多样性增加,短链脂肪酸水平降低,可能导致肠道炎症反应增加。