The objective of this study was to analyse the effects of propylene glycol (PPG) supplementation to periparturient cows on: milk yield, changes in body condition score (BCS), days to first oestrus after calving, and on the beta-hydroxybutyrate (BHBA), non-esterefied fatty acids (NEFA) and glucose concentrations. Twenty-three Holstein cows were distributed into two treatments: a) 300 mL of PPG (group treatment, 11 cows), b) 300 mL of water (group control, 12 cows), administered via drench in periparturient period. BCS was evaluated on days -10, 0, 15, 30, 45 and 60 relative to calving date. There was no effect of treatment or time on milk yield, although the interaction of time*treatment was significant and during the 4th and 5th week of lactation, milk yield was significant higher in treatment group. Days to first oestrus of PPG and control group were on average 40.2 and 45.2 respectively (P>0.05). There was no effect of treatment on body condition score (BCS) from calving to sixty days post partum. There was no effect of treatment or interaction of time*treatment on plasma parameters (BHBA, NEFA and glucose) but there was an effect of time on glucose and NEFA. However, based on an analysis of covariance, using BCS as the covariate, an effect of treatment on plasma concentrations of BHBA was observed. In conclusion, supplementation of propyleneglycol has a minor effect to alleviate the negative metabolic effects that normally occur at early lactation in dairy cows.
dairy cow; propylene glycol; milk yield; body condition score; reproductive performance
