Samiei A, Liang J B, Ghorbani G R, Hirooka H, Yaakub H, Tabatabaei M
Laboratory of Industrial Biotechnology, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Malaysia.
Pol J Vet Sci. 2010;13(2):349-56.
The first objective of this study was to investigate the relationship between concentrations of beta-hydroxybutyrate (BHBA) in milk and blood to assess the reliability of the BHBA concentrations in milk measured by a semi quantitative keto-test paper to detect subclinical ketosis (SCK) in 50 fresh high-producing Iranian Holstein cows in Golestan Province, Iran. The second objective was the effects of SCK on milk yield and components. Concentrations of nonesterified fatty acids (NEFA) and BHBA were analyzed quantitatively in blood plasma and commercial keto-test paper was used for semi quantitative determination of BHBA concentration in milk. Milk yield was measured until 60 d after calving but milk compositions were measured until 30 d after calving. The mean plasma BHBA, milk BHBA, plasma NEFA, milk yield, milk fat percentage and milk fat: protein ratio were 1,234 micromol/L, 145 micromol/L, 0.482 mEq/L, 29.5 kg, 3.9% and 1.4, respectively. Fifty eight percent of the cows had SCK during the first month of lactation. High correlation coefficients were observed between blood BHBA and blood NEFA, and between blood and milk BHBA. The milk yield of cattle with SCK decreased (P < 0.01) but the fat percentage and milk fat: protein ratio increased (P < 0.01). The commercial keto-test paper used had a low false positive result at a cut-off point of 200 fmol of BHBA/L of milk. The results showed that the best time to assess SCK using the commercial keto-test paper was d 10, 14 and 17 after calving.
本研究的首要目标是调查牛奶和血液中β-羟基丁酸（BHBA）浓度之间的关系，以评估用半定量酮试纸测定伊朗戈勒斯坦省50头高产新鲜荷斯坦奶牛牛奶中BHBA浓度来检测亚临床酮病（SCK）的可靠性。第二个目标是研究亚临床酮病对产奶量和乳成分的影响。对血浆中的非酯化脂肪酸（NEFA）和BHBA浓度进行定量分析，并使用商用酮试纸对牛奶中的BHBA浓度进行半定量测定。记录产犊后60天内的产奶量，但乳成分测定至产犊后30天。血浆BHBA、牛奶BHBA、血浆NEFA、产奶量、乳脂率和乳脂与蛋白质比的平均值分别为1234微摩尔/升、145微摩尔/升、0.482毫当量/升、29.5千克、3.9%和1.4。58%的奶牛在泌乳的第一个月患有亚临床酮病。血液中BHBA与血液中NEFA之间以及血液与牛奶中BHBA之间观察到高相关系数。患有亚临床酮病的奶牛产奶量下降（P<0.01），但乳脂率和乳脂与蛋白质比升高（P<0.01）。所用的商用酮试纸在牛奶中BHBA浓度为200飞摩尔/升的截断点时假阳性结果较低。结果表明，使用商用酮试纸评估亚临床酮病的最佳时间是产犊后第10、14和17天。
