Gordon J L, LeBlanc S J, Kelton D F, Herdt T H, Neuder L, Duffield T F
Department of Population Medicine, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Department of Large Animal Clinical Sciences, Michigan State University, East Lansing 48824.
J Dairy Sci. 2017 May;100(5):3912-3921. doi: 10.3168/jds.2016-11926. Epub 2017 Mar 2.
The purpose of this study was to determine the effects of a butaphosphan-cyanocobalamin combination product (B+C) and 2 durations of propylene glycol treatment (PG; 3 versus 5 d) on ketosis resolution and early lactation milk yield. Cows from 9 freestall herds (8 in Ontario and 1 in Michigan) were tested at weekly intervals between 3 and 16 d in milk. Ketosis was defined as blood β-hydroxybutyrate (BHB) ≥1.2 mmol/L. Ketotic cows were randomly assigned to treatment with 25 mL of B+C or 25 mL of saline placebo for 3 d and 3 or 5 d of 300 g of PG orally in a 2 × 2 factorial arrangement. Outcomes evaluated for all farms included ketosis cure (blood BHB <1.2 mmol/L at 1 wk after enrollment), maintenance of ketosis cure (blood BHB <1.2 mmol/L 1 and 2 wk after enrollment), and blood BHB concentrations at 1 and 2 wk after enrollment. Daily milk weights were collected in 3 herds. Poisson regression was used to evaluate cure and maintenance of cure, whereas repeated-measures ANOVA was used to evaluate blood BHB concentrations in the 2 wk after enrollment and average daily milk production in the 30 d after treatment. A total of 594 animals were enrolled in the study with 124 treated with B+C and 5 d of PG, 176 treated with B+C and 3 d of PG, 128 treated with saline and 5 d of PG, and 166 treated with saline and 3 d of PG. Animals with blood BHB >2.4 mmol/L at the time of enrollment were 1.7 times more likely [95% confidence interval (CI): 1.4 to 2.2] to cure and had a decrease of 0.25 ± 0.11 mmol/L blood BHB at 1 wk after enrollment if treated with 5 d of PG compared with 3 d, though this response was not seen in animals with BHB of 1.2 to 2.4 mmol/L at enrollment. Cows with blood glucose concentrations <2.2 mmol/L at enrollment produced 3.1 kg/d (95% CI: 1.3 to 5.0) more milk if treated with B+C and 3.4 kg/d (95% CI: 1.7 to 5.1) more milk if treated with 5 d of PG compared with their respective controls. This response was not seen in animals with blood glucose ≥2.2 mmol/L at enrollment and there was no interaction between treatments. These results indicate that extended PG treatment is beneficial in decreasing blood BHB concentrations in more severely affected animals. Additionally, both B+C treatment and extended PG treatment improved milk yield in animals with low blood glucose at the time of ketosis diagnosis.
本研究的目的是确定布他磷 - 氰钴胺组合产品（B + C）以及两种丙二醇处理时长（PG；3天与5天）对酮病缓解和早期泌乳期产奶量的影响。来自9个散栏牛群（安大略省8个，密歇根州1个）的奶牛在产奶3至16天期间每周进行一次检测。酮病定义为血液β - 羟基丁酸（BHB）≥1.2 mmol/L。酮病奶牛被随机分配接受25 mL B + C或25 mL生理盐水安慰剂治疗3天，并以2×2析因设计口服300 g PG 3天或5天。对所有农场评估的结果包括酮病治愈（入组后1周血液BHB <1.2 mmol/L）、酮病治愈维持情况（入组后1周和2周血液BHB <1.2 mmol/L）以及入组后1周和2周的血液BHB浓度。在3个牛群中收集每日产奶量。采用泊松回归评估治愈情况和治愈维持情况，而重复测量方差分析用于评估入组后2周内的血液BHB浓度以及治疗后30天内的日均产奶量。共有594只动物纳入研究，其中124只接受B + C和5天PG治疗，176只接受B + C和3天PG治疗，128只接受生理盐水和5天PG治疗，166只接受生理盐水和3天PG治疗。入组时血液BHB >2.4 mmol/L的动物接受5天PG治疗时，治愈的可能性比接受3天PG治疗高1.7倍[95%置信区间（CI）：1.4至2.2]，且入组后1周血液BHB降低0.25±0.11 mmol/L，不过入组时BHB为1.2至2.4 mmol/L的动物未出现这种反应。入组时血糖浓度<2.2 mmol/L的奶牛接受B + C治疗时比各自的对照组多产奶3.1 kg/d（95% CI：1.3至5.0），接受5天PG治疗时比各自对照组多产奶3.4 kg/d（95% CI：1.7至5.1）。入组时血糖≥2.2 mmol/L的动物未出现这种反应，且各治疗之间无相互作用。这些结果表明，延长PG治疗对降低受影响更严重动物血液中的BHB浓度有益。此外，B + C治疗和延长PG治疗均提高了酮病诊断时血糖低的动物的产奶量。
