An exogenous avian leukosis virus (ALV) strain SDAU09C1 was isolated in DF-1 cells from one of 240 imported 1-day-old white meat-type grand parent breeder chicks. Inoculation of SDAU09C1 in ALV-free chickens induced a...An exogenous avian leukosis virus (ALV) strain SDAU09C1 was isolated in DF-1 cells from one of 240 imported 1-day-old white meat-type grand parent breeder chicks. Inoculation of SDAU09C1 in ALV-free chickens induced antibody reactions specific to subgroup A or B. But gp85 amino acid sequence comparisons indicated that SDAU09C1 fell into subgroup A; it had homology of 88.8%-90.3% to 6 reference strains of subgroup A, much higher compared to other subgroups including subgroup B. This is the first report for ALV of subgroup A isolated from imported breeders.展开更多
Two hundred and sixty four broiler breeder hens of 32 weeks of age were distributed randomly in four dietary treatments. The dietary treatments were T0: Broiler breeder ration containing 40 ppm zinc (basal 29.8 ppm + ...Two hundred and sixty four broiler breeder hens of 32 weeks of age were distributed randomly in four dietary treatments. The dietary treatments were T0: Broiler breeder ration containing 40 ppm zinc (basal 29.8 ppm + 10.2 ppm inorganic zinc), T1: T0 + organic zinc (zinc methionine) @ 20 ppm, T2: T0 + organic zinc @ 40 ppm and T3: T0 + organic zinc @ 60 ppm. The experiment was continued from 32 to 48 weeks of age. At 48 weeks, the weight of lymphoid organs, zinc levels in organs and immunity response were determined. The faecal zinc level was determined at monthly interval. The weight lymphoid organs of different treatment groups (both organic and inorganic zinc fed groups) of the broiler breeders did not differ significantly (P > 0.05). The cellular immune response of breeder birds to PHA-P was significantly (P 0.05) higher in group T3 than the rest of treated groups. The antibody titre to SRBC differed among the treated groups. The zinc content of serum of broiler breeders of all the groups did not differ significantly (P > 0.05) in all the periods of study. Zinc content in liver and tibia of broiler breeders in different dietary treatments of zinc differed significantly (P 0.05) with higher levels were obtained on increasing zinc concentration in the diet. The zinc level in the spleen and kidney of the broiler breeders in different dietary treatments did not differ significantly (P > 0.05). The average zinc content in the faeces of broiler breeder during 35 to 43 week of age did not differ significantly (P > 0.05) among the treated groups. At 48 weeks of age, zinc content of the faeces of T3 was found to be significantly (P 0.05) higher than the rest of treated groups. Similarly, during the overall experimental period analysis, it was found that zinc levels in the faeces of T2 and T3 were significantly (P 0.05) higher than T1 and T0.展开更多
Molecular markers,genome sequencing and genome editing are considered as efficient tools to accomplish demands of plant breeders for crop improvement programs.Morphological and biochemical markers have not been extens...Molecular markers,genome sequencing and genome editing are considered as efficient tools to accomplish demands of plant breeders for crop improvement programs.Morphological and biochemical markers have not been extensively used as these are greatly influenced by environmental factors.Different molecular markers and sequencing techniques are routinely used in evaluation of genetic diversity and evolutionary relationship,accurate classification or taxonomy,characterization of germplasm,identification of hybrids and phylogenetic studies.Desired and undesired traits controlled by genes can be identified through different molecular markers technology all over the globe.These molecular markers are well established and have successfully been used for genetic analysis of different plants during last two decades.Recently,advanced techniques of molecular markers have been developed,which provide advance genotypic platform and tends to merge valuable properties of many basic systems.New class of markers also includes little modifications in basic methods to enhance the sensitivity and resolution.Biotechnologists,plant breeders and strong investment are strongly linked for crop improvement purposes.Current review provides detailed description of different markers,genome sequencing and genome editing that have been utilized for different genetic analyses of horticultural crops.Genome editing technologies based on CRISPR/Cas are now successfully applied in horticultural crops.Moreover,current review encourages the use of molecular marker technology for DNA fingerprinting,bar coding,sequencing,re-sequencing QTL mapping,genome association mapping and genome editing.It is need of time that diverse germplasm should be identified with different molecular techniques and further utilized in breeding purposes to achieve higher yielding and resistant cultivars against biotic and abiotic stresses.展开更多
The spread of antibiotic resistance, whether in the community or in the hospital, has recently become a major public health problem. Moreover, livestock seems to be a reservoir of resistant microorganisms such as porc...The spread of antibiotic resistance, whether in the community or in the hospital, has recently become a major public health problem. Moreover, livestock seems to be a reservoir of resistant microorganisms such as porcine methicillin resistant Staphylococcus aureus (P-MRSA) whose carriage and transmission was mainly demonstrated in persons with occupational exposure to pigs. Much uncertainty remains about the public health implications of P-MRSA. To address concerns that exist regarding the zoonotic risk that pig carriers pose to breeders, the prevalence of P-MRSA in pigs and pig breeders was determined among 152 pig breeders in three regions of Cameroon. Materials and Method: Participants in this study came from Adamawa, Far North and Littoral regions of Cameroon. A total of 152 pig breeders or farm workers participated in this study. After having collected some social and cultural data with the aid of a questionnaire, nasal swabs were collected from pigs (n = 275) and their breeders using the standard collection procedures and placed in cooler containing cold accumulators. For each sample, microbiological assays were done as well as antibiotic susceptibility tests. Results: MRSA was isolated from 25 out of 275 pigs sampled (9.09%) and from 32 out of 152 (21.05%) pig breeders sampled;33 breeders (21.71%) were carriers of S. aureus including 32 MRSA and one MSSA. The prevalence of MRSA nasal carriage was 21.05% ± 6.48. A significant negative association between body protection and nasal carriage of MRSA (OR = 0.29, 95% CI [0.093;0.93];p = 0.04) was observed. In each region, similar strains of MRSA were isolated both in pigs and their breeders with the same antibiotic resistant profile. Conclusion: The prevalence of MRSA though not high compared to European countries warrants further research as data on this zoonosis is scarce in our context. As such, transmission of MRSA from pigs to pig breeders or vice-versa constitutes a real danger, and this relationship may be a starting point for MRSA contamination in the c展开更多
Hetero-element doped lithium orthosilicates have been considered as advanced tritium breeders due to the superior performances.In this work,Li_(4)Si_(1-x)Ti_(x)O_(4) ceramics were prepared by proprietary hydrothermal ...Hetero-element doped lithium orthosilicates have been considered as advanced tritium breeders due to the superior performances.In this work,Li_(4)Si_(1-x)Ti_(x)O_(4) ceramics were prepared by proprietary hydrothermal process and multistage reactive sintering.The reaction mechanism of Li_(4)Si_(1-x)Ti_(x)O_(4) was put forward.XRD and SEM analyses indicate that insertion of Ti leads to lattice expansion,which promotes the grain growth and changes the fracture mode.The compressive tests show that the crush load increases almost four times by increasing x from 0 to 0.2.However,the thermal conductivity and ionic conductivity are the best when x=0.05 and x=0.1,respectively.Thermal cycling stability of Li_(4)Si_(1-x)Ti_(x)O_(4) pebbles was further appraised through investigating the changes of microstructure and crush load.After undergoing thermal cycling,the Li_(4)Si_(1-x)Ti_(x)O_(4) still show higher crush load compared with Li_(4)SiO_(4),despite Ti segregation in some samples.The x=0.05 sample exhibits excellent thermal cycling stability.In summary,proper amount of Ti doping can improve the crush load,thermal and ionic conductivity,and thermal cycling stability of Li_(4)SiO_(4).展开更多
Salmonella is a ubiquitous pathogen which, in addition to causing poultry diseases, has a growing zoonotic impact. It has demanded the implementation of diverse control strategies, in which vaccines play a major role....Salmonella is a ubiquitous pathogen which, in addition to causing poultry diseases, has a growing zoonotic impact. It has demanded the implementation of diverse control strategies, in which vaccines play a major role. The understanding of the immune pathways elicited by the different vaccines is important, contributing for the establishment of strong immune correlates of protection, for instance. With the purpose of determining the dynamics of the humoral and cellular immune responses to vaccination, broiler breeders (Cobb Slow) were immunized with live or inactivated vaccines against Salmonella Enteritidis. Lymphocyte and macrophage subsets were analyzed in the peripheral blood by flow cytometry and antigen-specific circulating IgY and mucosal IgA were quantified. The markers analyzed by flow cytometry were CD8/CD28, CD4/TCRVβ1, Kul/ MHC II and Bu-1. Both live and inactivated vaccines induced an increase in the proportion of circulating monocytes (Kul+MHCII+) in some time points compared to non-vaccinated controls. However, whereas the live vaccine leads to an increase in CD8-CD28+ and Bu-1+ lymphocytescompared to the control group, the inactivated vaccine prompteda reduction in the percentage of severalleucocyte subsets (Kul-MHCII+, Bu-1+, CD8+CD28+, CD8-CD28+, CD4+TCRVβ1-, CD4+TCRVβ1+, CD4-TCRVβ1+) after the boost dose. Both vaccines induced specific serum IgY and mucosal IgA production;however, the inactivated vaccine stimulated higher titers in a shorter period. These results contribute to the understanding of mechanisms of action of live and inactivated Salmonella vaccines in chickens.展开更多
Mycoplasma synoviae （MS） is an economically important pathogenic agent of chickens, causing air sacculitis and synovitis. The diagnosis and monitoring of M. synoviae infection is usually made using serological assay...Mycoplasma synoviae （MS） is an economically important pathogenic agent of chickens, causing air sacculitis and synovitis. The diagnosis and monitoring of M. synoviae infection is usually made using serological assays, while confirmative diagnosis is made by isolation and identifcation of the organism, because of the cross reaction between M. gallisepticum and M. synoviae. This study was conducted from 2011 to 2013 during which l l broiler breeder flocks were sampled. These farms were located in all regions of morocco, The sampling was conducted as follows： Farms were visited on day one old chicks ＂day of importation from Europe＂. 20 to 60 ＂chicks＂ were randomly sampled. At the age of 8, 16, 32 and 56 weeks, 60 blood samples and 60 tracheal swabs were collected at each sampling. The serological screening was performed using Rapid Slide Agglutination （RSA） according the OIE protocol and Indirect EL1SA （IDEXX） according the manufacturer＇s instructions. The molecular diagnosis was performed using a commercial kit of a duplex real time PCR （Life Biotechnology）. The results revealed that one day old chicks were negative to MS by RSA and PCR, however they have a variable stock of maternal antibodies （Ig-Y） detected by iELISA. The seroprevalence found by RSA is variable and increase with the age （Sth week： 55%, 16th week： 91%, 32tb and 56th week： 100%）, the same profile was traced by PCR （Sth week： 36%, 16th week： 64%, 32th week： 82%, 56th week： 100%）, however, all farms were positive by iELISA, from the first day to 56th weeks. These results show that MS infections are very frequent and very widespread among poultry breeder flocks, and showed a perfect agreement between serological tests and Real time PCR starting from 32th week of age.展开更多
A study was conducted to determine the effects of dietary digestible amino acids of feedstuffs and true metabolizable energy corrected for nitrogen on broiler breeder performance in 50 weeks to 64 weeks of age. 140 fe...A study was conducted to determine the effects of dietary digestible amino acids of feedstuffs and true metabolizable energy corrected for nitrogen on broiler breeder performance in 50 weeks to 64 weeks of age. 140 females and 20 males broiler breeders in 4 treatments with 5 replicates （7 females with a male） were used in the form of a completely randomized trial design 2 ~ 2 factorial. Four experimental diets were formulation based on two factors, first factor was included, two types of Apparent and True Metabolizable Energy corrected for Nitrogen （AMEn and TMEn） and the second factor was included, two types of Total Amino Acids （TAA） and Digestible （DAA） of feedstuffs. The result showed that egg weight, egg production （%） and egg mass （g/hen/day） was significantly different which was affected by diets formulation based on energy and interaction between energy and amino acids （P 〈 0.01）. Treatment 2 （AMEn ＋ DAA） was at the highest level significantly different （P 〈 0.01） in egg weight 68.97 g, egg production 62.45%, and egg mass 43. i g/hen/day. Hatching eggs were significantly different which was affected by diet formulation based on amino acids. Fertility, hatchability and number of chicks per hen were significant different, that were affected by diet formulation based on energy （P 〈 0.05）. Interaction between two factors, were significantly different in two reproductive traits fertility and hatchability （P 〈 0.05）. This experiment showed that diet formulation based on AMEn and DAA for broiler breeder was better and significant on performance.展开更多
基金supported by a grant from Shandong province and a grant (200803019) from the Ministry of Agriculturesupported by a grant from Shandong province and a grant (20080019) from the Ministry of Agriculture
文摘An exogenous avian leukosis virus (ALV) strain SDAU09C1 was isolated in DF-1 cells from one of 240 imported 1-day-old white meat-type grand parent breeder chicks. Inoculation of SDAU09C1 in ALV-free chickens induced antibody reactions specific to subgroup A or B. But gp85 amino acid sequence comparisons indicated that SDAU09C1 fell into subgroup A; it had homology of 88.8%-90.3% to 6 reference strains of subgroup A, much higher compared to other subgroups including subgroup B. This is the first report for ALV of subgroup A isolated from imported breeders.
文摘Two hundred and sixty four broiler breeder hens of 32 weeks of age were distributed randomly in four dietary treatments. The dietary treatments were T0: Broiler breeder ration containing 40 ppm zinc (basal 29.8 ppm + 10.2 ppm inorganic zinc), T1: T0 + organic zinc (zinc methionine) @ 20 ppm, T2: T0 + organic zinc @ 40 ppm and T3: T0 + organic zinc @ 60 ppm. The experiment was continued from 32 to 48 weeks of age. At 48 weeks, the weight of lymphoid organs, zinc levels in organs and immunity response were determined. The faecal zinc level was determined at monthly interval. The weight lymphoid organs of different treatment groups (both organic and inorganic zinc fed groups) of the broiler breeders did not differ significantly (P > 0.05). The cellular immune response of breeder birds to PHA-P was significantly (P 0.05) higher in group T3 than the rest of treated groups. The antibody titre to SRBC differed among the treated groups. The zinc content of serum of broiler breeders of all the groups did not differ significantly (P > 0.05) in all the periods of study. Zinc content in liver and tibia of broiler breeders in different dietary treatments of zinc differed significantly (P 0.05) with higher levels were obtained on increasing zinc concentration in the diet. The zinc level in the spleen and kidney of the broiler breeders in different dietary treatments did not differ significantly (P > 0.05). The average zinc content in the faeces of broiler breeder during 35 to 43 week of age did not differ significantly (P > 0.05) among the treated groups. At 48 weeks of age, zinc content of the faeces of T3 was found to be significantly (P 0.05) higher than the rest of treated groups. Similarly, during the overall experimental period analysis, it was found that zinc levels in the faeces of T2 and T3 were significantly (P 0.05) higher than T1 and T0.
文摘Molecular markers,genome sequencing and genome editing are considered as efficient tools to accomplish demands of plant breeders for crop improvement programs.Morphological and biochemical markers have not been extensively used as these are greatly influenced by environmental factors.Different molecular markers and sequencing techniques are routinely used in evaluation of genetic diversity and evolutionary relationship,accurate classification or taxonomy,characterization of germplasm,identification of hybrids and phylogenetic studies.Desired and undesired traits controlled by genes can be identified through different molecular markers technology all over the globe.These molecular markers are well established and have successfully been used for genetic analysis of different plants during last two decades.Recently,advanced techniques of molecular markers have been developed,which provide advance genotypic platform and tends to merge valuable properties of many basic systems.New class of markers also includes little modifications in basic methods to enhance the sensitivity and resolution.Biotechnologists,plant breeders and strong investment are strongly linked for crop improvement purposes.Current review provides detailed description of different markers,genome sequencing and genome editing that have been utilized for different genetic analyses of horticultural crops.Genome editing technologies based on CRISPR/Cas are now successfully applied in horticultural crops.Moreover,current review encourages the use of molecular marker technology for DNA fingerprinting,bar coding,sequencing,re-sequencing QTL mapping,genome association mapping and genome editing.It is need of time that diverse germplasm should be identified with different molecular techniques and further utilized in breeding purposes to achieve higher yielding and resistant cultivars against biotic and abiotic stresses.
文摘The spread of antibiotic resistance, whether in the community or in the hospital, has recently become a major public health problem. Moreover, livestock seems to be a reservoir of resistant microorganisms such as porcine methicillin resistant Staphylococcus aureus (P-MRSA) whose carriage and transmission was mainly demonstrated in persons with occupational exposure to pigs. Much uncertainty remains about the public health implications of P-MRSA. To address concerns that exist regarding the zoonotic risk that pig carriers pose to breeders, the prevalence of P-MRSA in pigs and pig breeders was determined among 152 pig breeders in three regions of Cameroon. Materials and Method: Participants in this study came from Adamawa, Far North and Littoral regions of Cameroon. A total of 152 pig breeders or farm workers participated in this study. After having collected some social and cultural data with the aid of a questionnaire, nasal swabs were collected from pigs (n = 275) and their breeders using the standard collection procedures and placed in cooler containing cold accumulators. For each sample, microbiological assays were done as well as antibiotic susceptibility tests. Results: MRSA was isolated from 25 out of 275 pigs sampled (9.09%) and from 32 out of 152 (21.05%) pig breeders sampled;33 breeders (21.71%) were carriers of S. aureus including 32 MRSA and one MSSA. The prevalence of MRSA nasal carriage was 21.05% ± 6.48. A significant negative association between body protection and nasal carriage of MRSA (OR = 0.29, 95% CI [0.093;0.93];p = 0.04) was observed. In each region, similar strains of MRSA were isolated both in pigs and their breeders with the same antibiotic resistant profile. Conclusion: The prevalence of MRSA though not high compared to European countries warrants further research as data on this zoonosis is scarce in our context. As such, transmission of MRSA from pigs to pig breeders or vice-versa constitutes a real danger, and this relationship may be a starting point for MRSA contamination in the c
基金supported by National Natural Science Foundation of China(No.51802257)Natural Science Foundation of Shaanxi Provincial Department of Education(18JK0570)China Postdoctoral Science Foundation(2019M663788).
文摘Hetero-element doped lithium orthosilicates have been considered as advanced tritium breeders due to the superior performances.In this work,Li_(4)Si_(1-x)Ti_(x)O_(4) ceramics were prepared by proprietary hydrothermal process and multistage reactive sintering.The reaction mechanism of Li_(4)Si_(1-x)Ti_(x)O_(4) was put forward.XRD and SEM analyses indicate that insertion of Ti leads to lattice expansion,which promotes the grain growth and changes the fracture mode.The compressive tests show that the crush load increases almost four times by increasing x from 0 to 0.2.However,the thermal conductivity and ionic conductivity are the best when x=0.05 and x=0.1,respectively.Thermal cycling stability of Li_(4)Si_(1-x)Ti_(x)O_(4) pebbles was further appraised through investigating the changes of microstructure and crush load.After undergoing thermal cycling,the Li_(4)Si_(1-x)Ti_(x)O_(4) still show higher crush load compared with Li_(4)SiO_(4),despite Ti segregation in some samples.The x=0.05 sample exhibits excellent thermal cycling stability.In summary,proper amount of Ti doping can improve the crush load,thermal and ionic conductivity,and thermal cycling stability of Li_(4)SiO_(4).
文摘Salmonella is a ubiquitous pathogen which, in addition to causing poultry diseases, has a growing zoonotic impact. It has demanded the implementation of diverse control strategies, in which vaccines play a major role. The understanding of the immune pathways elicited by the different vaccines is important, contributing for the establishment of strong immune correlates of protection, for instance. With the purpose of determining the dynamics of the humoral and cellular immune responses to vaccination, broiler breeders (Cobb Slow) were immunized with live or inactivated vaccines against Salmonella Enteritidis. Lymphocyte and macrophage subsets were analyzed in the peripheral blood by flow cytometry and antigen-specific circulating IgY and mucosal IgA were quantified. The markers analyzed by flow cytometry were CD8/CD28, CD4/TCRVβ1, Kul/ MHC II and Bu-1. Both live and inactivated vaccines induced an increase in the proportion of circulating monocytes (Kul+MHCII+) in some time points compared to non-vaccinated controls. However, whereas the live vaccine leads to an increase in CD8-CD28+ and Bu-1+ lymphocytescompared to the control group, the inactivated vaccine prompteda reduction in the percentage of severalleucocyte subsets (Kul-MHCII+, Bu-1+, CD8+CD28+, CD8-CD28+, CD4+TCRVβ1-, CD4+TCRVβ1+, CD4-TCRVβ1+) after the boost dose. Both vaccines induced specific serum IgY and mucosal IgA production;however, the inactivated vaccine stimulated higher titers in a shorter period. These results contribute to the understanding of mechanisms of action of live and inactivated Salmonella vaccines in chickens.
文摘Mycoplasma synoviae （MS） is an economically important pathogenic agent of chickens, causing air sacculitis and synovitis. The diagnosis and monitoring of M. synoviae infection is usually made using serological assays, while confirmative diagnosis is made by isolation and identifcation of the organism, because of the cross reaction between M. gallisepticum and M. synoviae. This study was conducted from 2011 to 2013 during which l l broiler breeder flocks were sampled. These farms were located in all regions of morocco, The sampling was conducted as follows： Farms were visited on day one old chicks ＂day of importation from Europe＂. 20 to 60 ＂chicks＂ were randomly sampled. At the age of 8, 16, 32 and 56 weeks, 60 blood samples and 60 tracheal swabs were collected at each sampling. The serological screening was performed using Rapid Slide Agglutination （RSA） according the OIE protocol and Indirect EL1SA （IDEXX） according the manufacturer＇s instructions. The molecular diagnosis was performed using a commercial kit of a duplex real time PCR （Life Biotechnology）. The results revealed that one day old chicks were negative to MS by RSA and PCR, however they have a variable stock of maternal antibodies （Ig-Y） detected by iELISA. The seroprevalence found by RSA is variable and increase with the age （Sth week： 55%, 16th week： 91%, 32tb and 56th week： 100%）, the same profile was traced by PCR （Sth week： 36%, 16th week： 64%, 32th week： 82%, 56th week： 100%）, however, all farms were positive by iELISA, from the first day to 56th weeks. These results show that MS infections are very frequent and very widespread among poultry breeder flocks, and showed a perfect agreement between serological tests and Real time PCR starting from 32th week of age.
文摘A study was conducted to determine the effects of dietary digestible amino acids of feedstuffs and true metabolizable energy corrected for nitrogen on broiler breeder performance in 50 weeks to 64 weeks of age. 140 females and 20 males broiler breeders in 4 treatments with 5 replicates （7 females with a male） were used in the form of a completely randomized trial design 2 ~ 2 factorial. Four experimental diets were formulation based on two factors, first factor was included, two types of Apparent and True Metabolizable Energy corrected for Nitrogen （AMEn and TMEn） and the second factor was included, two types of Total Amino Acids （TAA） and Digestible （DAA） of feedstuffs. The result showed that egg weight, egg production （%） and egg mass （g/hen/day） was significantly different which was affected by diets formulation based on energy and interaction between energy and amino acids （P 〈 0.01）. Treatment 2 （AMEn ＋ DAA） was at the highest level significantly different （P 〈 0.01） in egg weight 68.97 g, egg production 62.45%, and egg mass 43. i g/hen/day. Hatching eggs were significantly different which was affected by diet formulation based on amino acids. Fertility, hatchability and number of chicks per hen were significant different, that were affected by diet formulation based on energy （P 〈 0.05）. Interaction between two factors, were significantly different in two reproductive traits fertility and hatchability （P 〈 0.05）. This experiment showed that diet formulation based on AMEn and DAA for broiler breeder was better and significant on performance.
