The dairy herd improvement data from Henan Province were analyzed statistically to establish screening criteria for relevant data, thereby laying a foundation for genetic evaluation of dairy cows. With the 2 152 451 t...The dairy herd improvement data from Henan Province were analyzed statistically to establish screening criteria for relevant data, thereby laying a foundation for genetic evaluation of dairy cows. With the 2 152 451 test-day records about 155 893 Chinese Holstein dairy cows collected by the Henan Dairy Herd Improvement Center from January 2008 to April 2016, the dynamics of test times during a complete lactation, test interval during a complete lactation, days in milk （DIM） of first test-day record, daughter descendant number and herd number of bull, age at first calving and pedigree integrity rate among different years and different herd sizes were analyzed by MEANS order of SAS 9.4. In addition, the data that were applicable to genetic evaluation were screened by SQL program. The results showed that during 2008-2015, the number of cow individuals participating in DHI in Henan Province increased from 7 379 to 93 706; the test-day milk yield increased from 19.91 to 24.05 kg; the somatic cell count reduced from 411.09×10^3 to 277.08×10^3 cells/ml; the percentage of cows with DIM ranging from 5-305 d reached 70.92%; the average test times increased from 3.20 to 6.31 times; the test interval decreased from 70.22 to 33.83 d; the dairy cows with age at first calving of 25 months were dominant, accounting for 12.57%; the bulls whose daughter descendant number was 20 or more and the daughters were distributed in 10 or more farms accounted for 6.05%; the one-generation pedigree integrity rate was 82.54%; the percentage of data that could be used for genetic evaluation was screened as 20.67%, which was lower than the results of other similar studies.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
基金Supported by Science and Technology Open Cooperation Project of Henan Province(162106000017)Science and Technology People-benefiting Plan Project of Henan Province(152207110004)Puyang Science and Technology Plan Project(150109)~~
文摘The dairy herd improvement data from Henan Province were analyzed statistically to establish screening criteria for relevant data, thereby laying a foundation for genetic evaluation of dairy cows. With the 2 152 451 test-day records about 155 893 Chinese Holstein dairy cows collected by the Henan Dairy Herd Improvement Center from January 2008 to April 2016, the dynamics of test times during a complete lactation, test interval during a complete lactation, days in milk （DIM） of first test-day record, daughter descendant number and herd number of bull, age at first calving and pedigree integrity rate among different years and different herd sizes were analyzed by MEANS order of SAS 9.4. In addition, the data that were applicable to genetic evaluation were screened by SQL program. The results showed that during 2008-2015, the number of cow individuals participating in DHI in Henan Province increased from 7 379 to 93 706; the test-day milk yield increased from 19.91 to 24.05 kg; the somatic cell count reduced from 411.09×10^3 to 277.08×10^3 cells/ml; the percentage of cows with DIM ranging from 5-305 d reached 70.92%; the average test times increased from 3.20 to 6.31 times; the test interval decreased from 70.22 to 33.83 d; the dairy cows with age at first calving of 25 months were dominant, accounting for 12.57%; the bulls whose daughter descendant number was 20 or more and the daughters were distributed in 10 or more farms accounted for 6.05%; the one-generation pedigree integrity rate was 82.54%; the percentage of data that could be used for genetic evaluation was screened as 20.67%, which was lower than the results of other similar studies.
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.
