The Variation of Somatic Cell Counts, Electrical Conductivities, Milk Serum Lactate Dehydrogenase and its isoenzymes activities from calving to three months of postpaturient period in Holstein Cows

• Main Authors: Pi Lien Chang, 張碧蓮
• Other Authors: Huo-Cheng Peh
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/14770558469957857741

碩士 === 國立中興大學 === 畜產學系 === 87 === The purposes of this study were conducted to investigate the relationships of the somatic cell counts (SCC), electrical conductivities (EC) and milk serum lactate dehydrogenase (LDH) activities in the quarter milk and the effects of parity, stage of lactation, different quarter, infected and uninfected status on SCC, EC and LDH activities. The experiment was starting from December 1998 to May 1999. Milk samples were collected weekly from different quarter of 10 Holstein cows in the morning and afternoon milking from calving to three months of postparturient period. Milk samples were stored at 4℃for cell counting, EC and LDH activities analyses. There were significant correlation between the EC and SCC, LDH activities and SCC, LDH isoenyzmes activities and SCC. The correlation coefficient of SCC with EC were 0.2, while the correlation coefficient of SCC with the activities of LDH, LDH1, LDH2, LDH3, LDH 4 and LDH5 in milk were 0.5, -0.54, 0.49, 0.41, 0.48 and 0.36 respectively. EC increased with the lactation progressed. SCC and LDH activities in milk were highly significant increased (P<0.01) shortly after calving, then rapidly declined to a nadir at second week of postpartum period. In SCC<50104cells/ml group, SCC and LDH activities in milk maintained at 3.5104cells/ml to 13.5104cells/ml and 47.04IU/ml to 111.05IU/ml respectively. In SCC50104cells/ml group, SCC and LDH activities maintained at 100.2104cells/ml to 164.0104cells/ml and 85.15IU/ml to 143.27IU/ml respectively. SCC and LDH activities in foremilk were not affected by milking time, but EC of foremilk samples from morning milking were significant higher (P<0.01) than those of afternoon. In healthy cows, SCC, EC and LDH activities in milk from each quarter were similar. However, if one or more quarters were infected, then the SCC, EC and LDH activities in milk of infected quarter were higher than those of noninfected quarter. SCC, EC and the activities of LDH in milk were not affected by the parity. EC in milk was also not affected by the colonies of bacteria, but SCC and LDH activities in milk were significantly higher (P<0.01) when the colonies of bacteria were over forty.