College of Veterinary Medicine, University of Santo Tomas, Viña del Mar, Chile.
Theriogenology. 2009 Oct 1;72(6):826-33. doi: 10.1016/j.theriogenology.2009.06.001. Epub 2009 Aug 3.
The objective was to describe the relationship between concentration of serum nonesterified fatty acids (NEFAs) at calving and the incidence of periparturient disorders in Chilean Holstein dairy cows (Bos taurus). The study was conducted at two dairies (central Chile) with 700 milking cows each and similar management. Between July 2006 and March 2007, 350 cows were selected, and concentrations of serum NEFAs were determined at calving. The incidence of milk fever (MF), retained fetal membranes (RFMs), metritis, and clinical mastitis from calving to 100 d in lactation were consistently recorded. The relationship between concentration of serum NEFAs at calving and the incidence of periparturient diseases was determined using logistic regression. The main explanatory variable was concentration of serum NEFAs at calving. The incidence of MF, RFM, metritis, and mastitis was 5.4%, 15.6%, 10.8%, and 14.4%, respectively. There was no association between concentration of NEFAs at calving and the incidence of these conditions when the median value of NEFAs (0.9 mEq/L) was used as a cutoff. However, when the 75th percentile (1.2 mEq/L) was used as the cutoff, cows with values <1.2 mEq/L were 0.45 and 0.32 times as likely to develop clinical mastitis and MF, respectively, compared with cows with values >or=1.2 mEq/L. When the 90th percentile (1.6 mEq/L) was used as a cutoff, cows with values <1.6 mEq/L were 0.25 times as likely to develop clinical mastitis compared with cows with values >or=1.6 mEq/L. As a continuous variable, for every 0.1 mEq/L increment in NEFAs at calving, cows were 1.11 times more likely to experience clinical mastitis. In conclusion, cows with NEFA concentrations >or=1.2 mEq/L had a higher incidence of clinical mastitis and MF than that of cows with values <1.2 mEq/L.
目的在于描述智利荷斯坦奶牛（Bos taurus）分娩时血清非酯化脂肪酸（NEFA）浓度与围产期疾病发生率之间的关系。本研究在两家拥有 700 头奶牛且管理方式相似的奶牛场（智利中部）进行。2006 年 7 月至 2007 年 3 月期间，选择了 350 头奶牛，并在分娩时测定了血清 NEFA 浓度。连续记录了从分娩到泌乳 100 天的乳热（MF）、胎衣不下（RFM）、子宫炎和临床乳腺炎的发生率。使用逻辑回归确定了分娩时血清 NEFA 浓度与围产期疾病发生率之间的关系。主要解释变量为分娩时血清 NEFA 浓度。MF、RFM、子宫炎和乳腺炎的发生率分别为 5.4%、15.6%、10.8%和 14.4%。当以 NEFA 的中位数（0.9 mEq/L）作为截断值时，分娩时 NEFA 浓度与这些情况的发生率之间没有关联。然而，当使用第 75 百分位数（1.2 mEq/L）作为截断值时，NEFA 值<1.2 mEq/L 的奶牛发生临床乳腺炎和 MF 的可能性分别为 NEFA 值≥1.2 mEq/L 的奶牛的 0.45 倍和 0.32 倍。当使用第 90 百分位数（1.6 mEq/L）作为截断值时，NEFA 值<1.6 mEq/L 的奶牛发生临床乳腺炎的可能性为 NEFA 值≥1.6 mEq/L 的奶牛的 0.25 倍。作为一个连续变量，分娩时 NEFA 每增加 0.1 mEq/L，奶牛发生临床乳腺炎的可能性就会增加 1.11 倍。综上所述，NEFA 浓度≥1.2 mEq/L 的奶牛发生临床乳腺炎和 MF 的发生率高于 NEFA 浓度<1.2 mEq/L 的奶牛。
