Evaluation of propylene glycol and glycerol infusions as treatments for ketosis in dairy cows

摘要: To evaluate propylene glycol (PG) and glycerol (G) as potential treatments for ketosis, we conducted 2 experiments lasting 4 d each in which cows received one bolus infusion per day. Blood was collected before infusion, over 240min postinfusion, well 24 h postinfusion. Experiment 1 used 6 ruminally cannulated (26±7 milk) randomly assigned to 300-mL infusions of PG or G (both ≥99.5% pure) a crossover design experiment with periods. Within period, were site sequence: abomasum (A)-cranial reticulorumen (R) the reverse, R-A. Glucose precursors infused into R simulate drenching A prevent metabolism by ruminal microbes. Glycerol increased plasma glucose concentration most (15.8mg/dL), followed (12.6mg/dL), (9.11mg/dL), (7.3mg/dL). Infusion insulin area under curve (AUC) compared all other (7.88 vs. 2.13μIU/mL 321 31.9min×μIU/mL, respectively). Overall, decreased BHBA after (-6.46 -4.55mg/dL) AUC (-1,055 -558min ×mg/dL) G. Plasma NEFA responses not different among treatments. 8 (22±5 treatment sequence Latin square balanced carryover effects. Treatments 300mL PG, G, 600mL (2G), + (GPG), R. Treatment contrasts containing (G, 2G, GPG). Propylene (14.0 5.35mg/dL) (7.59 1.11μIU/mL) concentrations but only tended increase 2G. (1,444 94.3mg/dL) (326 6.58min×μIU/mL) from GPG glucose, insulin, responses. (-10.3 -4.21mg/dL) (-1,578 -1.42min In general, early late infusions. We conclude that dose is more effective at increasing than least combination when administered cranial reticulorumen.