The objective of this study was to analyze the relationship of somatic cell count （SCC） with milk yield, fat and protein percentage, fat and protein yield using analysis of variance and correlation analysis in Chine...The objective of this study was to analyze the relationship of somatic cell count （SCC） with milk yield, fat and protein percentage, fat and protein yield using analysis of variance and correlation analysis in Chinese Holstein population. The 10 524 test-day records of 568 Chinese Holstein Cattle were obtained from 2 commercial herds in Xi＇an region of China during February 2002 to March 2009. Milk yield, fat percentage, fat and protein yield initially increased and then dropped down with parity, whereas protein percentage decreased and SCC increased. Analysis of variance showed highly significant effects of different subclasses SCC on milk yield and composition （P〈 0.01）. Compared with milk yield with SCC ≤ 200 000 cells mL-1, milk yield losses with SCC of 200 000-500 000 cells mL-1, 501000-1 000 000 cells mL-1, ≥ 1 000 000 cells mL-1 were 0.387, 0.961 and 2.351 kg, respectively. The highly significant negative correlation coefficient between somatic cell score （SCS） and milk and protein yield, milk yield and fat and protein percentage, protein percentage and fat yield were -0.084, -0.037, -0.061, -0.168, and -0.088, respectively （P〈 0.01）. The highly significant positive correlation coefficients between SCS and fat yield and fat and protein percentage, milk yield and fat and protein yield, fat percentage and protein percentage and fat yield, protein yield and protein percentage and fat yield were 0.041, 0.177, 0.105, 0.771, 0.865, 0.122, 0.568, 0.318, and 0.695, respectively （P〈 0.01）. There was no significant relationship between fat percentage and protein yield （P 〉 0.05）. The results of the present study first time provide the relevant base-line data for assessing milk production at Xi＇an region of China.展开更多
The main aim of this study was to investigate the prevalence of intramammary infection (IMI) in early-lactation of primiparous cows using milk recording cow composite somatic cell count (CSCC) categories (combining th...The main aim of this study was to investigate the prevalence of intramammary infection (IMI) in early-lactation of primiparous cows using milk recording cow composite somatic cell count (CSCC) categories (combining the first 2 milk recording results after calving). Another aim was to evaluate the milk urea (MU) content as a potential supplementary indicator to SCC or CSCC for the identification of IMI in primiparous cows after calving. This retrospective observational study was conducted on records of test-day of primiparous cows over a period of 6 years (January 2016 to December 2021. The SCC data for 158 Holstein Friesian primiparous cows, with their first milk recording 5 to 35 days after calving and their second milk recording 28 to 56 days in milk (DIM), were identified. Each primiparous cow was assigned a CSCC category (low-low, low-high, high-low or high-high) based on the CSCC at the first 2 milking recordings using the following cut-offs: ≤150,000 cells/ml (low), >150,000 cells/ml (high). The association between CSCC categories and MV content was analyzed using correlation models. At the first milk recording, a proportion of 63.29% was in the low SCC category, and the rest (36.71%) was in the high SCC category. At the second milk recording, a proportion of primiparous cows in CSCC categories was 59.49%, 3.80%, 27.85% and 8.86% in low-low, low-high, high-low and high-high, respectively. At the second milk recording, a proportion of 12.66% of primiparous cows was in the high CSCC category and a proportion of 87.34% of primiparous cows was in the low CSCC category, indicating a poor and a good udder health, respectively. The association of SCC with MU content in low and in high SCC categories at the first milk recording was positive and moderate (+0.49) and negative and strong (-0.97), respectively. The association of CSCC categories with MU contents at the second milk recording was inconclusive. We concluded that CSCC categories may be a useful tool for identifying success and problems regarding the udder health of primiparous cows in early lactation.展开更多
The aim of this study was to evaluate the impact of the somatic cell count (SCC) levels measured at 28-test-day intervals or pregnancy rate at the first artificial insemination of Holstein Friesian cows. All necessary...The aim of this study was to evaluate the impact of the somatic cell count (SCC) levels measured at 28-test-day intervals or pregnancy rate at the first artificial insemination of Holstein Friesian cows. All necessary information was taken from test day and farm records. Levels of SCC in milk, 30 days before, and 30 days after the first artificial insemination (FAI) date were divided into 4 categories and their interconnection with pregnancy rate (PR) at FAI was evaluated by applying logistic models. A SCC threshold of 150.000 cells/ml of milk was used to differentiate uninfected udders and infected udders of Holstein Friesian cows. A level of SCC > 150.000 cells/ml in milk, and a level of SCC < 150.000 cells/ml before and after FAI respectively were considered udders with new infections. A level of SCC > 150.000 cells/ml in milk before FAI as well as after FAI, was considered chronically infected udders or subclinical intramammary infections (IMI). Data from 792 FAIs from farm and test day records over a 4-year period (2019-2022) were evaluated. The outcome of this study revealed that the risk for low PR at the first AI was increased in cows with infected udders (OR = 1.33, CI 0.99 - 1.78), compared with uninfected udders. Increased levels of SCC after FAI had a negative effect on PR, while before FAI was not affected. To achieve a good PR, mastitis control measures must be fully adopted to a large extent around the first AI.展开更多
Background:Inbreeding depression can adversely affect traits related to fitness,reproduction and productive performance.Although current research suggests that inbreeding levels are generally low in most goat breeds,t...Background:Inbreeding depression can adversely affect traits related to fitness,reproduction and productive performance.Although current research suggests that inbreeding levels are generally low in most goat breeds,the impact of inbreeding depression on phenotypes of economic interest has only been investigated in a few studies based on genealogical data.Results:We genotyped 1040 goats with the Goat SNP50 BeadChip.This information was used to estimate different molecular inbreeding coefficients and characterise runs of homozygosity and homozygosity patterns.We detected38 genomic regions with increased homozygosity as well as 8 ROH hotspots mapping to chromosomes 1,2,4,6,14,16 and 17.Eight hundred seventeen goats with available records for dairy traits were analysed to evaluate the potential consequences of inbreeding depression on milk phenotypes.Four regions on chromosomes 8 and 25were significantly associated with inbreeding depression for the natural logarithm of the somatic cell count.Notably,these regions contain several genes related with immunity,such as SYK,IL27,CCL19 and CCL21.Moreover,one region on chromosome 2 was significantly associated with inbreeding depression for milk yield.Conclusions:Although genomic inbreeding levels are low in Murciano-Granadina goats,significant evidence of inbreeding depression for the logarithm of the somatic cell count,a phenotype closely associated with udder health and milk yield,have been detected in this population.Minimising inbreeding would be expected to augment economic gain by increasing milk yield and reducing the incidence of mastitis,which is one of the main causes of dairy goat culling.展开更多
In Kosovo, a new regulation on quality standards and grade of fresh milk is valid since January 1, 2007. The regulation was based on the respective EU-regulation and has an ambitious time frame with a transition perio...In Kosovo, a new regulation on quality standards and grade of fresh milk is valid since January 1, 2007. The regulation was based on the respective EU-regulation and has an ambitious time frame with a transition period of only three years. In order to estimate the impact of this new regulation, a survey on the quality of raw milk delivered to the Kosovar dairies was carried out from January to May 2007. The aim was to get a reliable picture of the current raw milk quality in the dairy channel in Kosovo, to discuss the findings with the relevant actors of the dairy sector and the government, and to draw the necessary conclusions. In total 364 milk samples, from the leading 14 dairies constitute the basis for the statistical analyses of this study. The four most important parameters of raw milk quality: TBC, SCC, FP and AB were analyzed. Regarding TBC, the results show that around 20% of samples meet the Kosovo standard 2008 (< 500,000 CFU/ml) and only around 10% meet the (higher) Kosovo standard 2009 (<100,000 CFU/ml) while for SCC, around 80% of the samples meet the Kosovo standard 2008 (<600,000 cells/ml) and 66% meet the (higher) Kosovo standard 2009 (<400,000 cells/ml). Therefore at the moment the problem of high microbiological content is more prominent than the one of high somatic cell count. Beside this, in one third of the samples, the freezing point is at least questionable. In 2.2% of the samples antibiotics could be proven—a major risk for public health. Raw milk quality in Kosovo still is very poor and must be improved in order the dairy processors be able to produce qualitatively good end products and therefore can compete with imported dairy products or export their products.展开更多
The objective of this study was to develop and validate a colorimetric assay to measure caprine serum albumin (CSA) concentrations in milk. The principle of the say was based on the binding of albumin to bromocresol g...The objective of this study was to develop and validate a colorimetric assay to measure caprine serum albumin (CSA) concentrations in milk. The principle of the say was based on the binding of albumin to bromocresol green (BCG) dye at pH 4.0. The absorption of the dye-albumin complex was determined spectrophotometrically at 640 nm. A linear relationship existed between CSA concentrations (0.01 to 8.0 mg/ml) and absorbance values. Intra-assay and interassay coefficients of variation for the proposed assay were 2.6% and 12% respectively. Recovery from milk samples spiked with albumins was 89.15% ± 7.6%. The developed assay was validated using 126 milk samples collected from lactating Saanen goats at various stages of lactation`. Caprine serum albumin concentrations in milk ranged between 0.31 and 0.52 mg/ml. The concentrations of CSA were significantly higher展开更多
A study was performed to evaluate the epidemiological aspects of buffalo mastitis in the District Chitwan, Nepal for characterizing the California mastitis test （CMT）, somatic cell count （SCC）, electrical conducti...A study was performed to evaluate the epidemiological aspects of buffalo mastitis in the District Chitwan, Nepal for characterizing the California mastitis test （CMT）, somatic cell count （SCC）, electrical conductivity （EC） values and bacteriological analysis for defining buffalo milk. The CMT was performed by mixing equal volume of milk and 3% sodium lauryl sulphate. The SCC was determined by staining milk film with New Man’s Lampert Stain and EC values were measured by manual digital mastitis detector and expressed as mS/cm. Bacteriological analysis was done on the basis of Gram’s stain, morphological findings, colony characteristics and biochemical tests. The maximum number （16%） of clinical cases of mastitis was observed in the month of July and lowest in the month of April （1.6%）. When the temperature and humidity increased, it indicates that there is need for better care of lactating buffaloes during this month. On a quarter basis, 16% of the foremilk samples in buffaloes were diagnosed as having subclinical mastitis and 11% were diagnosed as having clinical mastitis. The results of CMT scores and SCC showed the evidence that subclinical and clinical mastitic milk was having CMT positive scores （＋1~＋3） with ≥ 200 × 103 cells/mL. The mean pH of clinically normal buffalo milk was 6.75 （range 6.39 to 7.08） and subclinical mastitic and clinical mastitic milk was 6.85 （range 6.37 to 7.10） and 6.88 （range 6.41 to 7.20）, respectively. Analysis of EC value in the milk revealed the presence of mastitis in buffaloes and the cut-off values was 3.7 mS/cm. The coagulase negative Staphylococcus （CNS）, such as S. albus and S. epidermidis were the predominant organisms associated with subclinical mastitis, and CNS and coliforms in clinical mastitis. This information suggests that environmental mastitis was prevalent in buffaloes of Chitwan District. In this study, 9.5% of the quarters were having bacterial count （BC） more than 250 cfu/mL. The proposed criteria for normal milk are absence of clinical signs, CMT negative, SCC 〈 200 × 10^3 cells/mL, EC 〈 3.7 mS/cm and 〈 250 cfu/mL bacteria. The parameters for defining subclinically mastitic milk are absence of clinical signs, CMT positive, SCC ≥ 200 × 10^3 cells/mL, EC 〉 3.7 mS/cm and 〉 250 cfu/mL bacteria. Similarly, clinical mastitic milk was defined as milk having presence of clinical signs, CMT positive, SCC ≥ 200 × 10^3 cells /mL, EC 〉 3.7 mS/cm and BC 〉 250 cfu/mL.展开更多
Samples of raw milk from bulk cooling tanks were collected in five municipalities of the Southwestern Brazilian Amazon to establish the prevalence of Staphylococcus aueus and Streptococcus agalactiae, as well as to ev...Samples of raw milk from bulk cooling tanks were collected in five municipalities of the Southwestern Brazilian Amazon to establish the prevalence of Staphylococcus aueus and Streptococcus agalactiae, as well as to evaluate the milk composition and its correlation with the bulk tank somatic cell count (BTSCC). A total of 250 samples were collected to investigate the causal agents of bovine mastitis in whole milk, from 50 bulk milk tanks in each municipality. Under laboratory conditions, the samples were diluted to 1/10 and 1/100, and samples of 0.1 ml from each dilution were plated in triplicate on selective media for Staphylococcus aureus and Streptococcus agalactiae. To evaluate the correlation between the major milk components (fat, protein and lactose) and the BTSCC, samples were collected for 18 months from 73 dairy herds. The presence of the above-mentioned contagious mastitis pathogens was detected in 97.2% (243/250) of refrigerated raw milk samples evaluated. Analysis of the major milk components and BTSCC demonstrated that during the study period, fat compo-nent showed the largest variance, followed by protein and lactose, which also showed significant variances.展开更多
Studies have reported on the economic impacts of clinical and subclinical mastitis on dairy farms.Bovine mastitis is a disorder that affects dairy farms and has a major economic impact.Most of the economic losses are ...Studies have reported on the economic impacts of clinical and subclinical mastitis on dairy farms.Bovine mastitis is a disorder that affects dairy farms and has a major economic impact.Most of the economic losses are the result of mastitis.Mastitis is an invasive infection that is among the most numerous and highly complicated infections in the dairy sector.Mastitis is one of the most expensive diseases in terms of production losses among animal diseases.Mastitis reduces milk production,changes milk composition,and shortens the productive life of infected cows.Farmers must concentrate on avoiding mastitis infection whilst putting in place and following a mastitis control programed.Bovine mastitis,the most significant disease of dairy herds,has huge effects on farm economics.Mastitis losses are due to reduced milk production,the cost of treatments,and culling.Major factors related to low milk yield could be low genetic potential as well as poor nutritional and managerial approaches.Most of the losses are related to somatic cell count(SCC),which is characterised by an increase in the percentage of milk.Culling costs are the costs of rearing or buying a replacement animal,mostly heifers.Overhead impacts include the replacement animals'lower milk supply effectiveness.The expense of replacing animals prematurely due to mastitis is one of the most significant areas of economic loss.展开更多
基金supported by the National 863 Program of China(2008AA10Z144)"13115"Sci-Tech Innovation Program of Shaanxi Province(2008ZDKG-11)
文摘The objective of this study was to analyze the relationship of somatic cell count （SCC） with milk yield, fat and protein percentage, fat and protein yield using analysis of variance and correlation analysis in Chinese Holstein population. The 10 524 test-day records of 568 Chinese Holstein Cattle were obtained from 2 commercial herds in Xi＇an region of China during February 2002 to March 2009. Milk yield, fat percentage, fat and protein yield initially increased and then dropped down with parity, whereas protein percentage decreased and SCC increased. Analysis of variance showed highly significant effects of different subclasses SCC on milk yield and composition （P〈 0.01）. Compared with milk yield with SCC ≤ 200 000 cells mL-1, milk yield losses with SCC of 200 000-500 000 cells mL-1, 501000-1 000 000 cells mL-1, ≥ 1 000 000 cells mL-1 were 0.387, 0.961 and 2.351 kg, respectively. The highly significant negative correlation coefficient between somatic cell score （SCS） and milk and protein yield, milk yield and fat and protein percentage, protein percentage and fat yield were -0.084, -0.037, -0.061, -0.168, and -0.088, respectively （P〈 0.01）. The highly significant positive correlation coefficients between SCS and fat yield and fat and protein percentage, milk yield and fat and protein yield, fat percentage and protein percentage and fat yield, protein yield and protein percentage and fat yield were 0.041, 0.177, 0.105, 0.771, 0.865, 0.122, 0.568, 0.318, and 0.695, respectively （P〈 0.01）. There was no significant relationship between fat percentage and protein yield （P 〉 0.05）. The results of the present study first time provide the relevant base-line data for assessing milk production at Xi＇an region of China.
文摘The main aim of this study was to investigate the prevalence of intramammary infection (IMI) in early-lactation of primiparous cows using milk recording cow composite somatic cell count (CSCC) categories (combining the first 2 milk recording results after calving). Another aim was to evaluate the milk urea (MU) content as a potential supplementary indicator to SCC or CSCC for the identification of IMI in primiparous cows after calving. This retrospective observational study was conducted on records of test-day of primiparous cows over a period of 6 years (January 2016 to December 2021. The SCC data for 158 Holstein Friesian primiparous cows, with their first milk recording 5 to 35 days after calving and their second milk recording 28 to 56 days in milk (DIM), were identified. Each primiparous cow was assigned a CSCC category (low-low, low-high, high-low or high-high) based on the CSCC at the first 2 milking recordings using the following cut-offs: ≤150,000 cells/ml (low), >150,000 cells/ml (high). The association between CSCC categories and MV content was analyzed using correlation models. At the first milk recording, a proportion of 63.29% was in the low SCC category, and the rest (36.71%) was in the high SCC category. At the second milk recording, a proportion of primiparous cows in CSCC categories was 59.49%, 3.80%, 27.85% and 8.86% in low-low, low-high, high-low and high-high, respectively. At the second milk recording, a proportion of 12.66% of primiparous cows was in the high CSCC category and a proportion of 87.34% of primiparous cows was in the low CSCC category, indicating a poor and a good udder health, respectively. The association of SCC with MU content in low and in high SCC categories at the first milk recording was positive and moderate (+0.49) and negative and strong (-0.97), respectively. The association of CSCC categories with MU contents at the second milk recording was inconclusive. We concluded that CSCC categories may be a useful tool for identifying success and problems regarding the udder health of primiparous cows in early lactation.
文摘The aim of this study was to evaluate the impact of the somatic cell count (SCC) levels measured at 28-test-day intervals or pregnancy rate at the first artificial insemination of Holstein Friesian cows. All necessary information was taken from test day and farm records. Levels of SCC in milk, 30 days before, and 30 days after the first artificial insemination (FAI) date were divided into 4 categories and their interconnection with pregnancy rate (PR) at FAI was evaluated by applying logistic models. A SCC threshold of 150.000 cells/ml of milk was used to differentiate uninfected udders and infected udders of Holstein Friesian cows. A level of SCC > 150.000 cells/ml in milk, and a level of SCC < 150.000 cells/ml before and after FAI respectively were considered udders with new infections. A level of SCC > 150.000 cells/ml in milk before FAI as well as after FAI, was considered chronically infected udders or subclinical intramammary infections (IMI). Data from 792 FAIs from farm and test day records over a 4-year period (2019-2022) were evaluated. The outcome of this study revealed that the risk for low PR at the first AI was increased in cows with infected udders (OR = 1.33, CI 0.99 - 1.78), compared with uninfected udders. Increased levels of SCC after FAI had a negative effect on PR, while before FAI was not affected. To achieve a good PR, mastitis control measures must be fully adopted to a large extent around the first AI.
基金funded by the European Regional Development Fund(FEDER)/Ministerio de Ciencia e Innovación-Agencia Estatal de Investigación/Project Reference grant:PID2019-105805RB-I00by the CERCA Programme/Generalitat de Catalunya+3 种基金the support of the Spanish Ministerio de Ciencia e Innovación for the Center of Excellence Severo Ochoa 2020–2023(CEX2019–000902-S)grant awarded to the Centre for Research in Agricultural Genomics(CRAG,Bellaterra,Spain)the support of the CERCA programme of the Generalitat de Catalunyafunded by a PhD fellowship from the China Scholarship Council(CSC)funded with a PhD fellowship Formación de Personal Investigador(BES-C-2017-079709)awarded by the Spanish Ministry of Economy and Competitivity。
文摘Background:Inbreeding depression can adversely affect traits related to fitness,reproduction and productive performance.Although current research suggests that inbreeding levels are generally low in most goat breeds,the impact of inbreeding depression on phenotypes of economic interest has only been investigated in a few studies based on genealogical data.Results:We genotyped 1040 goats with the Goat SNP50 BeadChip.This information was used to estimate different molecular inbreeding coefficients and characterise runs of homozygosity and homozygosity patterns.We detected38 genomic regions with increased homozygosity as well as 8 ROH hotspots mapping to chromosomes 1,2,4,6,14,16 and 17.Eight hundred seventeen goats with available records for dairy traits were analysed to evaluate the potential consequences of inbreeding depression on milk phenotypes.Four regions on chromosomes 8 and 25were significantly associated with inbreeding depression for the natural logarithm of the somatic cell count.Notably,these regions contain several genes related with immunity,such as SYK,IL27,CCL19 and CCL21.Moreover,one region on chromosome 2 was significantly associated with inbreeding depression for milk yield.Conclusions:Although genomic inbreeding levels are low in Murciano-Granadina goats,significant evidence of inbreeding depression for the logarithm of the somatic cell count,a phenotype closely associated with udder health and milk yield,have been detected in this population.Minimising inbreeding would be expected to augment economic gain by increasing milk yield and reducing the incidence of mastitis,which is one of the main causes of dairy goat culling.
文摘In Kosovo, a new regulation on quality standards and grade of fresh milk is valid since January 1, 2007. The regulation was based on the respective EU-regulation and has an ambitious time frame with a transition period of only three years. In order to estimate the impact of this new regulation, a survey on the quality of raw milk delivered to the Kosovar dairies was carried out from January to May 2007. The aim was to get a reliable picture of the current raw milk quality in the dairy channel in Kosovo, to discuss the findings with the relevant actors of the dairy sector and the government, and to draw the necessary conclusions. In total 364 milk samples, from the leading 14 dairies constitute the basis for the statistical analyses of this study. The four most important parameters of raw milk quality: TBC, SCC, FP and AB were analyzed. Regarding TBC, the results show that around 20% of samples meet the Kosovo standard 2008 (< 500,000 CFU/ml) and only around 10% meet the (higher) Kosovo standard 2009 (<100,000 CFU/ml) while for SCC, around 80% of the samples meet the Kosovo standard 2008 (<600,000 cells/ml) and 66% meet the (higher) Kosovo standard 2009 (<400,000 cells/ml). Therefore at the moment the problem of high microbiological content is more prominent than the one of high somatic cell count. Beside this, in one third of the samples, the freezing point is at least questionable. In 2.2% of the samples antibiotics could be proven—a major risk for public health. Raw milk quality in Kosovo still is very poor and must be improved in order the dairy processors be able to produce qualitatively good end products and therefore can compete with imported dairy products or export their products.
文摘The objective of this study was to develop and validate a colorimetric assay to measure caprine serum albumin (CSA) concentrations in milk. The principle of the say was based on the binding of albumin to bromocresol green (BCG) dye at pH 4.0. The absorption of the dye-albumin complex was determined spectrophotometrically at 640 nm. A linear relationship existed between CSA concentrations (0.01 to 8.0 mg/ml) and absorbance values. Intra-assay and interassay coefficients of variation for the proposed assay were 2.6% and 12% respectively. Recovery from milk samples spiked with albumins was 89.15% ± 7.6%. The developed assay was validated using 126 milk samples collected from lactating Saanen goats at various stages of lactation`. Caprine serum albumin concentrations in milk ranged between 0.31 and 0.52 mg/ml. The concentrations of CSA were significantly higher
文摘A study was performed to evaluate the epidemiological aspects of buffalo mastitis in the District Chitwan, Nepal for characterizing the California mastitis test （CMT）, somatic cell count （SCC）, electrical conductivity （EC） values and bacteriological analysis for defining buffalo milk. The CMT was performed by mixing equal volume of milk and 3% sodium lauryl sulphate. The SCC was determined by staining milk film with New Man’s Lampert Stain and EC values were measured by manual digital mastitis detector and expressed as mS/cm. Bacteriological analysis was done on the basis of Gram’s stain, morphological findings, colony characteristics and biochemical tests. The maximum number （16%） of clinical cases of mastitis was observed in the month of July and lowest in the month of April （1.6%）. When the temperature and humidity increased, it indicates that there is need for better care of lactating buffaloes during this month. On a quarter basis, 16% of the foremilk samples in buffaloes were diagnosed as having subclinical mastitis and 11% were diagnosed as having clinical mastitis. The results of CMT scores and SCC showed the evidence that subclinical and clinical mastitic milk was having CMT positive scores （＋1~＋3） with ≥ 200 × 103 cells/mL. The mean pH of clinically normal buffalo milk was 6.75 （range 6.39 to 7.08） and subclinical mastitic and clinical mastitic milk was 6.85 （range 6.37 to 7.10） and 6.88 （range 6.41 to 7.20）, respectively. Analysis of EC value in the milk revealed the presence of mastitis in buffaloes and the cut-off values was 3.7 mS/cm. The coagulase negative Staphylococcus （CNS）, such as S. albus and S. epidermidis were the predominant organisms associated with subclinical mastitis, and CNS and coliforms in clinical mastitis. This information suggests that environmental mastitis was prevalent in buffaloes of Chitwan District. In this study, 9.5% of the quarters were having bacterial count （BC） more than 250 cfu/mL. The proposed criteria for normal milk are absence of clinical signs, CMT negative, SCC 〈 200 × 10^3 cells/mL, EC 〈 3.7 mS/cm and 〈 250 cfu/mL bacteria. The parameters for defining subclinically mastitic milk are absence of clinical signs, CMT positive, SCC ≥ 200 × 10^3 cells/mL, EC 〉 3.7 mS/cm and 〉 250 cfu/mL bacteria. Similarly, clinical mastitic milk was defined as milk having presence of clinical signs, CMT positive, SCC ≥ 200 × 10^3 cells /mL, EC 〉 3.7 mS/cm and BC 〉 250 cfu/mL.
文摘Samples of raw milk from bulk cooling tanks were collected in five municipalities of the Southwestern Brazilian Amazon to establish the prevalence of Staphylococcus aueus and Streptococcus agalactiae, as well as to evaluate the milk composition and its correlation with the bulk tank somatic cell count (BTSCC). A total of 250 samples were collected to investigate the causal agents of bovine mastitis in whole milk, from 50 bulk milk tanks in each municipality. Under laboratory conditions, the samples were diluted to 1/10 and 1/100, and samples of 0.1 ml from each dilution were plated in triplicate on selective media for Staphylococcus aureus and Streptococcus agalactiae. To evaluate the correlation between the major milk components (fat, protein and lactose) and the BTSCC, samples were collected for 18 months from 73 dairy herds. The presence of the above-mentioned contagious mastitis pathogens was detected in 97.2% (243/250) of refrigerated raw milk samples evaluated. Analysis of the major milk components and BTSCC demonstrated that during the study period, fat compo-nent showed the largest variance, followed by protein and lactose, which also showed significant variances.
文摘Studies have reported on the economic impacts of clinical and subclinical mastitis on dairy farms.Bovine mastitis is a disorder that affects dairy farms and has a major economic impact.Most of the economic losses are the result of mastitis.Mastitis is an invasive infection that is among the most numerous and highly complicated infections in the dairy sector.Mastitis is one of the most expensive diseases in terms of production losses among animal diseases.Mastitis reduces milk production,changes milk composition,and shortens the productive life of infected cows.Farmers must concentrate on avoiding mastitis infection whilst putting in place and following a mastitis control programed.Bovine mastitis,the most significant disease of dairy herds,has huge effects on farm economics.Mastitis losses are due to reduced milk production,the cost of treatments,and culling.Major factors related to low milk yield could be low genetic potential as well as poor nutritional and managerial approaches.Most of the losses are related to somatic cell count(SCC),which is characterised by an increase in the percentage of milk.Culling costs are the costs of rearing or buying a replacement animal,mostly heifers.Overhead impacts include the replacement animals'lower milk supply effectiveness.The expense of replacing animals prematurely due to mastitis is one of the most significant areas of economic loss.
