Incidence of hypocalcemia and its changes of biochemical parameters in periparturient cows
2012
Shu, Shi, Heilongjiang Bayi Agricultural University, Daqing, China | Xia, Cheng, Heilongjiang Bayi Agricultural University, Daqing, China | Xu, Chuang, Heilongjiang Bayi Agricultural University, Daqing, China | Zhang, Hongyyou, Heilongjiang Bayi Agricultural University, Daqing, China | Wu, Ling, Heilongjiang Bayi Agricultural University, Daqing, China
In this study, we investigate the status of calcium (Ca) homeostasis at parturition in three dairy farms (Ⅰ, Ⅱ, and Ⅲ), Heilongjiang, China. Twenty multiparous Holstein cows from each farm were randomly assigned to this experiment. The dietary cation-anion difference (DCAD) was 91 mEq/kg of DM for farm Ⅰ, 152 mEq/kg of DM for farm Ⅱ, and 85 mEq/kg of DM for farm Ⅲ. Incidence of hypocalcemia was above 75% and urine pH was above 7.25 at calving in each farm. Compared to other farms, cows in farm Ⅱ that fed the greatest positive DCAD had the lowest concentration of serum Ca, the highest concentration of serum PTH, and the greatest urine pH at calving (p less than 0.05). However, there was not significant difference in serum 1,25-dihydroxy-vitamin D and hydroxyproline concentration of the cows among three farms. This is the first study to confirm that hypocalcemia is very prevalent at calving in Chinese dairy farms, and the high positive DCAD is a major risk factor that results in hypocalcemia at calving, which may reduce ability of the cow to maintain Ca homeostasis.
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