Brucellosis is an important zoonosis that results in substantial economic losses to the livestock industry through abortions and reduced milk yield.This study investigated an abortion outbreak in a dairy herd and then...Brucellosis is an important zoonosis that results in substantial economic losses to the livestock industry through abortions and reduced milk yield.This study investigated an abortion outbreak in a dairy herd and then explored the efects of emergency vaccination with Brucella abortus A19 vaccine on the incidence of abortion and milk yield.A full dose of vaccine(6×10^(10)—12×10^(10)colony forming units,CFU)was administered subcutaneously to calves and non-pregnant heifers,and a reduced dose(6×10^(8)—12×10^(8)CFU)to adult cows and pregnant replacement heifers.Rose Bengal Test was used to screen Brucella infection status and then positive samples were tested with a C-ELISA.Animals that tested positive for both tests were considered positive to Brucella spp.The animal-level seroprevalence of brucellosis was 23.1%(95%CI:17.0,30.2),and the attributable fraction of abortions in seropositive animals was 89.1%(95%CI:64.3,96.7).The odds of seropositivity were signifcantly higher in cows that aborted compared to cows that calved normally(OR=21.4,95%CI:4.4,168.4).Cows in sheds A2 and C1 were 10.2(95%CI:1.4,128.0)and 17.0(95%CI:2.8,190.3)times more likely to be seropositive than cows in shed B1.Antibodies were not detectable in most heifers 12 months post-vaccination.The efectiveness of the vaccine in preventing abortions was estimated to be 56.8%(95%CI:15.8,77.8)for the entire herd,but increased to 86.7%(95%CI:4.4,98.1)when only primiparous heifers were considered.Furthermore,a signifcant increase in the average herd 305-day milk yield one-year after vaccination was also observed relative to that in the previous three years.It is concluded that emergency vaccination of a dairy herd undergoing an abortion outbreak with the A19 vaccine efectively reduced the incidence of abortion and indirectly increased milk yield one-year after vaccination.展开更多
A cross-sectional study was conducted to evaluate the risk factors associated with the Salmonella infection status of dairy herds in Henan and Hubei provinces,China.Herds were assigned a Salmonella status based on the...A cross-sectional study was conducted to evaluate the risk factors associated with the Salmonella infection status of dairy herds in Henan and Hubei provinces,China.Herds were assigned a Salmonella status based on the isolation of Salmonella from fecal samples obtained from adult lactating dairy cows.Information on potential biosecurity risk factors was collected using a questionnaire template via a 15-min face-to-face interview with dairy cattle producers from May 2020 to March 2021.The questionnaire consisted of 23 questions across two broad categories of potential biosecurity risk factors:farm and biosecurity managemental factors.A total of 48 farms were surveyed.In all(100%,48/48)of the surveyed farms,although sick animals were separated from healthy animals using fencing,there were no strict quarantine protocols for newly introduced animals.Mixed species rearing was practiced in 35.4%(17/48)of the farms.Feces were removed more than once a day in 45.8%(22/48)of the farms,whereas the remainder(54.2%,26/48)only removed animal feces once a day.A total of 29.2%(14/48)of the farms were located<2 km from other livestock farms.The use of personal protective equipment was consistently performed on all farms,with a major-ity of the workers on most farms(81.3%,39/48)always disinfecting footwear before entering production areas.A significant association between Salmonella-positive status and the high frequency of the presence of wildlife(birds and rodents in sheds and feed storage places)was recorded(OR:11.9,95%Cl:1.7,84.1,p=0.013).Fortunately,no farms shared farm equipment with other farms.The study highlights the occurrence of wildlife as a risk factor for the presence of Salmonella in investigated dairy herds.There is a need to institute appropriate on-farm control measures for wild birds and rodents to control the potential spread of Salmonella in dairy production systems.展开更多
Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and ass...Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and associated economic losses for the herd owner.This study was designed to investigate the relationship between milk and serum antibody tests for bTB in dairy cows using 85 cows with milk and corresponding blood samples.Totally 4,395 milk samples were used to assesse the apparent(test)prevalence and incidence of bTB using the milk antibody ELISA.The association between levels of bTB milk antibody and milk quality was also evaluated.Milk and serum antibody tests showed a good correlation with a 87.5%(95%CI:61.7%,98.4)positive agreement and 98.7%(95%CI:95.4,99.8)negative agreement.The animal level lactoprevalence ranged from 0.3%(95%CI:0,1.2)to 33.3%(95%CI:26.6,40.6)in different farms and the incidence rate ranged from 0 head/cow-month(95%CI:0,0.02)to 0.04 head/cow-month(95%CI:0.02,0.07).Twenty percent of sampled farms met the criteria for bTB control in China.The prevalence on large-scale farms was lower(p<0.001)than on small farms.The bTB milk antibody levels had a negative correlation with milk yield and a positive correlation with somatic cell count(SCC),milk protein percentage(MPP)and percentage of total solids(TS).According to this research,milk ELISA could be used as a supplement of blood samples to assist in the surveillance for bTB and for alerting control and eradication of bTB.展开更多
In order to reduce the risks for the spread of disease in cattle movements, we investigated China’s cattle breeding and movement pattern, analyzed risk factors of disease infection caused by long-distance movement, e...In order to reduce the risks for the spread of disease in cattle movements, we investigated China’s cattle breeding and movement pattern, analyzed risk factors of disease infection caused by long-distance movement, explored the relevant risk management measures and conjectured the direction of cattle movement based on the regional distribution of cattle inventory and beef price. We also constructed a market value chain in live cattle movements and qualitatively analyzed the risks for unapparent infection in the process of movement. Meanwhile, we put forward a long-term policy of reducing the risks for unapparent infection and animal health supervision measures.展开更多
基金supported by the earmarked fund for China Agriculture Research System(Beef/Yaks)(#CARS-37)National Science Foundation of Hubei Province(#2021CFA016).
文摘Brucellosis is an important zoonosis that results in substantial economic losses to the livestock industry through abortions and reduced milk yield.This study investigated an abortion outbreak in a dairy herd and then explored the efects of emergency vaccination with Brucella abortus A19 vaccine on the incidence of abortion and milk yield.A full dose of vaccine(6×10^(10)—12×10^(10)colony forming units,CFU)was administered subcutaneously to calves and non-pregnant heifers,and a reduced dose(6×10^(8)—12×10^(8)CFU)to adult cows and pregnant replacement heifers.Rose Bengal Test was used to screen Brucella infection status and then positive samples were tested with a C-ELISA.Animals that tested positive for both tests were considered positive to Brucella spp.The animal-level seroprevalence of brucellosis was 23.1%(95%CI:17.0,30.2),and the attributable fraction of abortions in seropositive animals was 89.1%(95%CI:64.3,96.7).The odds of seropositivity were signifcantly higher in cows that aborted compared to cows that calved normally(OR=21.4,95%CI:4.4,168.4).Cows in sheds A2 and C1 were 10.2(95%CI:1.4,128.0)and 17.0(95%CI:2.8,190.3)times more likely to be seropositive than cows in shed B1.Antibodies were not detectable in most heifers 12 months post-vaccination.The efectiveness of the vaccine in preventing abortions was estimated to be 56.8%(95%CI:15.8,77.8)for the entire herd,but increased to 86.7%(95%CI:4.4,98.1)when only primiparous heifers were considered.Furthermore,a signifcant increase in the average herd 305-day milk yield one-year after vaccination was also observed relative to that in the previous three years.It is concluded that emergency vaccination of a dairy herd undergoing an abortion outbreak with the A19 vaccine efectively reduced the incidence of abortion and indirectly increased milk yield one-year after vaccination.
基金supported by the Natural Science Foundation of Hubei Province(2021CFA016)the earmarked fund for China Agricultural Research System(Beef/Yaks)(#CARS-37).
文摘A cross-sectional study was conducted to evaluate the risk factors associated with the Salmonella infection status of dairy herds in Henan and Hubei provinces,China.Herds were assigned a Salmonella status based on the isolation of Salmonella from fecal samples obtained from adult lactating dairy cows.Information on potential biosecurity risk factors was collected using a questionnaire template via a 15-min face-to-face interview with dairy cattle producers from May 2020 to March 2021.The questionnaire consisted of 23 questions across two broad categories of potential biosecurity risk factors:farm and biosecurity managemental factors.A total of 48 farms were surveyed.In all(100%,48/48)of the surveyed farms,although sick animals were separated from healthy animals using fencing,there were no strict quarantine protocols for newly introduced animals.Mixed species rearing was practiced in 35.4%(17/48)of the farms.Feces were removed more than once a day in 45.8%(22/48)of the farms,whereas the remainder(54.2%,26/48)only removed animal feces once a day.A total of 29.2%(14/48)of the farms were located<2 km from other livestock farms.The use of personal protective equipment was consistently performed on all farms,with a major-ity of the workers on most farms(81.3%,39/48)always disinfecting footwear before entering production areas.A significant association between Salmonella-positive status and the high frequency of the presence of wildlife(birds and rodents in sheds and feed storage places)was recorded(OR:11.9,95%Cl:1.7,84.1,p=0.013).Fortunately,no farms shared farm equipment with other farms.The study highlights the occurrence of wildlife as a risk factor for the presence of Salmonella in investigated dairy herds.There is a need to institute appropriate on-farm control measures for wild birds and rodents to control the potential spread of Salmonella in dairy production systems.
基金the Natural Science Foundation of China(U21A20259)National Key Research and Development Program of Ningxia Hui Autonomous Region(2021BEF02028)+1 种基金the Natural Science Foundation of Hubei Province(2021CFA016)China Agriculture Research System of MOF and MARA and Basic and technical innovation team for prevention and control of bovine disease.
文摘Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and associated economic losses for the herd owner.This study was designed to investigate the relationship between milk and serum antibody tests for bTB in dairy cows using 85 cows with milk and corresponding blood samples.Totally 4,395 milk samples were used to assesse the apparent(test)prevalence and incidence of bTB using the milk antibody ELISA.The association between levels of bTB milk antibody and milk quality was also evaluated.Milk and serum antibody tests showed a good correlation with a 87.5%(95%CI:61.7%,98.4)positive agreement and 98.7%(95%CI:95.4,99.8)negative agreement.The animal level lactoprevalence ranged from 0.3%(95%CI:0,1.2)to 33.3%(95%CI:26.6,40.6)in different farms and the incidence rate ranged from 0 head/cow-month(95%CI:0,0.02)to 0.04 head/cow-month(95%CI:0.02,0.07).Twenty percent of sampled farms met the criteria for bTB control in China.The prevalence on large-scale farms was lower(p<0.001)than on small farms.The bTB milk antibody levels had a negative correlation with milk yield and a positive correlation with somatic cell count(SCC),milk protein percentage(MPP)and percentage of total solids(TS).According to this research,milk ELISA could be used as a supplement of blood samples to assist in the surveillance for bTB and for alerting control and eradication of bTB.
文摘In order to reduce the risks for the spread of disease in cattle movements, we investigated China’s cattle breeding and movement pattern, analyzed risk factors of disease infection caused by long-distance movement, explored the relevant risk management measures and conjectured the direction of cattle movement based on the regional distribution of cattle inventory and beef price. We also constructed a market value chain in live cattle movements and qualitatively analyzed the risks for unapparent infection in the process of movement. Meanwhile, we put forward a long-term policy of reducing the risks for unapparent infection and animal health supervision measures.
