Milk quality in bulk tank milk （BTM） is measured by flow cytometry technology as total bacterial count （TBC） and somatic cell count （SCC）. To investigate SCC problems, culture or PCR can be used to identify mast...Milk quality in bulk tank milk （BTM） is measured by flow cytometry technology as total bacterial count （TBC） and somatic cell count （SCC）. To investigate SCC problems, culture or PCR can be used to identify mastitis causing bacteria, e.g., Mastit 4, a commercially available qPCR test. TBC in BTM can be investigated further using culture-based methods such as standard plate count, laboratory pasteurization count, coliform count, and spore counts. To our knowledge, no qPCR addressing the bacteria involved in TBC has been commercially introduced. The aim of this study is to evaluate a recently introduced 3-h qPCR test, TBC 4. The TBC 4 qPCR detects four target groups, Pseudomonas, Streptococci, Enterobacteriacea/ Enterococcus, and Bacillus/Clostridia. These target groups relate to problems on the farm such as cooling, mastitis, environment, and silage. We will continue with new research to compare the TBC 4 qPCR test with traditional culture. For this study, BTM samples from different TBC intervals were selected based on BactoCount results found at routine payment investigation at Eurofins laboratory （Vejen, Denmark）. These samples were analyzed using TBC 4 qPCR assay within 24 h. In total, 346 BTM samples were divided into six different intervals of colony forming units （CFU）. For all four targets in each of the different intervals of CFU, the percent of positive samples, the average Ct-value, the percent of positive samples with Ct〈30 and Ct〈25 were calculated. For Pseudomonas, Streptococci, and Enterobacteriacea/Enterococcus, the number of positive samples with lower Ct-values （high bacteria content） correlated with the CFU mL-1. We found Enterobacteriacea/ Enterococcus, Pseudomonas, and Streptococci in high number of bacteria （Ct〈25） in 25, 19 and 56％ of samples with CFU mL-1 between 50001-100000 and 53, 44, and 39％ in samples with CFU mL-1〉100000. The TBC 4 qPCR test showed to be a strong and fast tool for farmers, advisors and service technicians to address problems with high TBC and ensuring the delivery of good quality milk to the dairy.展开更多
Background:Determination of nutrient requirements in the late gestating and lactating sows is essential to optimize sow productivity.The objectives of the present study were to quantify amino acid(AA)fluxes and heat p...Background:Determination of nutrient requirements in the late gestating and lactating sows is essential to optimize sow productivity.The objectives of the present study were to quantify amino acid(AA)fluxes and heat production across portal-drained viscera(PDV)and liver in multiparous sows during transition and lactation.Methods:Eight second parity sows were fitted with indwelling catheters in the femoral artery and in the mesenteric,portal and hepatic veins.Eight hourly sets of blood samples were taken starting 0.5 h before feeding at−10,−3,+3,and+17 d in milk(DIM).Blood gases,plasma metabolites and apparent total tract digestibility(ATTD)of nutrients were measured.Results:Feed intake,the ATTD of DM,energy,nitrogen,fat and crude fiber changed with DIM(P<0.001).Except for Glu,O2,and urea,all net portal fluxes were positive,and all were affected by DIM(P<0.05)and by sampling time(P<0.01).Compared with pre partum levels,net portal uptake of AA was 3-63%lower at+3 DIM but 40-100%higher at+17 DIM.Net portal fluxes of AA peaked at 1.5 to 2.5 h after feeding except for Glu,and they were positively correlated with changes in sow feed intake across DIM.The net portal recovery was low for Met(49%),Thr(54%),and His(54%)and high for the remaining essential AA(63-69%)and none of them differed across DIM.Net hepatic uptake(i.e.hepatic oxidation)of Lys,Thr,Ile,Leu and Phe peaked at 0.5 to 2.5 h after feeding,whereas uptake of Trp,Val,and His was constant,while that of Met was close to zero.Conclusion:The net portal recovery was substantially lower for Met,Thr,and His than the remaining essential AA.Hepatic AA oxidation peaks 0.5 to 2.5 h after feeding.The heat production in PDV and liver was approximately two-fold higher at peak lactation compared to other stages.The study suggests that lysine was the limiting AA in peak lactation but not in early lactation.展开更多
Background:Survival from birth to slaughter is an important economic trait in commercial pig productions.Increasing survival can improve both economic efficiency and animal welfare.The aim of this study is to explore ...Background:Survival from birth to slaughter is an important economic trait in commercial pig productions.Increasing survival can improve both economic efficiency and animal welfare.The aim of this study is to explore the impact of genotyping strategies and statistical models on the accuracy of genomic prediction for survival in pigs during the total growing period from birth to slaughter.Results:We simulated pig populations with different direct and maternal heritabilities and used a linear mixed model,a logit model,and a probit model to predict genomic breeding values of pig survival based on data of individual survival records with binary outcomes(0,1).The results show that in the case of only alive animals having genotype data,unbiased genomic predictions can be achieved when using variances estimated from pedigreebased model.Models using genomic information achieved up to 59.2%higher accuracy of estimated breeding value compared to pedigree-based model,dependent on genotyping scenarios.The scenario of genotyping all individuals,both dead and alive individuals,obtained the highest accuracy.When an equal number of individuals(80%)were genotyped,random sample of individuals with genotypes achieved higher accuracy than only alive individuals with genotypes.The linear model,logit model and probit model achieved similar accuracy.Conclusions:Our conclusion is that genomic prediction of pig survival is feasible in the situation that only alive pigs have genotypes,but genomic information of dead individuals can increase accuracy of genomic prediction by 2.06%to 6.04%.展开更多
文摘Milk quality in bulk tank milk （BTM） is measured by flow cytometry technology as total bacterial count （TBC） and somatic cell count （SCC）. To investigate SCC problems, culture or PCR can be used to identify mastitis causing bacteria, e.g., Mastit 4, a commercially available qPCR test. TBC in BTM can be investigated further using culture-based methods such as standard plate count, laboratory pasteurization count, coliform count, and spore counts. To our knowledge, no qPCR addressing the bacteria involved in TBC has been commercially introduced. The aim of this study is to evaluate a recently introduced 3-h qPCR test, TBC 4. The TBC 4 qPCR detects four target groups, Pseudomonas, Streptococci, Enterobacteriacea/ Enterococcus, and Bacillus/Clostridia. These target groups relate to problems on the farm such as cooling, mastitis, environment, and silage. We will continue with new research to compare the TBC 4 qPCR test with traditional culture. For this study, BTM samples from different TBC intervals were selected based on BactoCount results found at routine payment investigation at Eurofins laboratory （Vejen, Denmark）. These samples were analyzed using TBC 4 qPCR assay within 24 h. In total, 346 BTM samples were divided into six different intervals of colony forming units （CFU）. For all four targets in each of the different intervals of CFU, the percent of positive samples, the average Ct-value, the percent of positive samples with Ct〈30 and Ct〈25 were calculated. For Pseudomonas, Streptococci, and Enterobacteriacea/Enterococcus, the number of positive samples with lower Ct-values （high bacteria content） correlated with the CFU mL-1. We found Enterobacteriacea/ Enterococcus, Pseudomonas, and Streptococci in high number of bacteria （Ct〈25） in 25, 19 and 56％ of samples with CFU mL-1 between 50001-100000 and 53, 44, and 39％ in samples with CFU mL-1〉100000. The TBC 4 qPCR test showed to be a strong and fast tool for farmers, advisors and service technicians to address problems with high TBC and ensuring the delivery of good quality milk to the dairy.
基金supported by the Danish Pig Levy Fund(Project“Rasp”)and Aarhus University.Liang Hu received a scholarship provided by China Scholarship Council.
文摘Background:Determination of nutrient requirements in the late gestating and lactating sows is essential to optimize sow productivity.The objectives of the present study were to quantify amino acid(AA)fluxes and heat production across portal-drained viscera(PDV)and liver in multiparous sows during transition and lactation.Methods:Eight second parity sows were fitted with indwelling catheters in the femoral artery and in the mesenteric,portal and hepatic veins.Eight hourly sets of blood samples were taken starting 0.5 h before feeding at−10,−3,+3,and+17 d in milk(DIM).Blood gases,plasma metabolites and apparent total tract digestibility(ATTD)of nutrients were measured.Results:Feed intake,the ATTD of DM,energy,nitrogen,fat and crude fiber changed with DIM(P<0.001).Except for Glu,O2,and urea,all net portal fluxes were positive,and all were affected by DIM(P<0.05)and by sampling time(P<0.01).Compared with pre partum levels,net portal uptake of AA was 3-63%lower at+3 DIM but 40-100%higher at+17 DIM.Net portal fluxes of AA peaked at 1.5 to 2.5 h after feeding except for Glu,and they were positively correlated with changes in sow feed intake across DIM.The net portal recovery was low for Met(49%),Thr(54%),and His(54%)and high for the remaining essential AA(63-69%)and none of them differed across DIM.Net hepatic uptake(i.e.hepatic oxidation)of Lys,Thr,Ile,Leu and Phe peaked at 0.5 to 2.5 h after feeding,whereas uptake of Trp,Val,and His was constant,while that of Met was close to zero.Conclusion:The net portal recovery was substantially lower for Met,Thr,and His than the remaining essential AA.Hepatic AA oxidation peaks 0.5 to 2.5 h after feeding.The heat production in PDV and liver was approximately two-fold higher at peak lactation compared to other stages.The study suggests that lysine was the limiting AA in peak lactation but not in early lactation.
基金funded by the"Genetic improvement of pig survival"project from Danish Pig Levy Foundation (Aarhus,Denmark)The China Scholarship Council (CSC)for providing scholarship to the first author。
文摘Background:Survival from birth to slaughter is an important economic trait in commercial pig productions.Increasing survival can improve both economic efficiency and animal welfare.The aim of this study is to explore the impact of genotyping strategies and statistical models on the accuracy of genomic prediction for survival in pigs during the total growing period from birth to slaughter.Results:We simulated pig populations with different direct and maternal heritabilities and used a linear mixed model,a logit model,and a probit model to predict genomic breeding values of pig survival based on data of individual survival records with binary outcomes(0,1).The results show that in the case of only alive animals having genotype data,unbiased genomic predictions can be achieved when using variances estimated from pedigreebased model.Models using genomic information achieved up to 59.2%higher accuracy of estimated breeding value compared to pedigree-based model,dependent on genotyping scenarios.The scenario of genotyping all individuals,both dead and alive individuals,obtained the highest accuracy.When an equal number of individuals(80%)were genotyped,random sample of individuals with genotypes achieved higher accuracy than only alive individuals with genotypes.The linear model,logit model and probit model achieved similar accuracy.Conclusions:Our conclusion is that genomic prediction of pig survival is feasible in the situation that only alive pigs have genotypes,but genomic information of dead individuals can increase accuracy of genomic prediction by 2.06%to 6.04%.
