Detection, Occurrence, and Prophylactic Treatment of Borderline Ketosis with Propylene Glycol Feeding

Abstract

Milk ketones were determined by a new test at weekly intervals for 132 cows freshening in two herds in one year and for 61 cows in two herds for a second year. If the milk ketones exceeded 2 mg/100 ml during the first year, alternate cows were treated daily with 12 oz propylene glycol for ten days, or served as controls. The cows were controls or fed propylene glycol (4 or 8 oz/day) from the time of calving during the second year's study. Milk ketones in excess of 2 mg/100 ml occurred in 49% of the population during the first 30 days postpartum. Propylene glycol lowered milk ketones an average of 0.6 mg/100 ml over the entire population and increased milk production 1 lb/cow/day for the first 60 days postpartum. These over-all differences were not significant at the 5% probability level, although significant differences did occur within herds. Three cows given intraruminal doses of 2 lb propylene glycol were used to demonstrate a rumen disappearance half-time of 1 hr. Subsequent blood levels ranged as high as 57 mg/100 ml. Ruminal destruction of propylene glycol was small. Metabolism trials with four cows demonstrated that body retention of propylene glycol exceeded 99% even when 5.4 lb/day was fed. Excretion of propylene glycol in milk was less than 0.1% of the dose (below detection limits). © 1964, American Dairy Science Association. All rights reserved.