Influence of propylene glycol and glycerin in Simmental cows in periparturient period on milk yield and metabolic changes

Abstract. The aim of this study was to compare the influence of propylene glycol and glycerin added to Total Mixed Ration (TMR) dose on lipid-carbohydrate metabolism, activity of selected liver enzymes and milk yield of Simmental cows in periparturient period. Forty two cows of Simmental breed were divided into 3 groups (n=14). Cows from the experimental groups were given 300 ml/d of either propylene glycol or glycerin from 7th day prepartum to 21st day postpartum. In week 5 of lactation in cows that were given propylene glycol and in week 12 in cows receiving glycerin Body Condition Score (BCS) was higher as compared to control cows. An application of glycerin resulted in the highest milk yield. Higher glucose content in groups that were given propylene glycol and glycerin would have contributed to the reduction of negative energy balance at the beginning of lactation. The lowest increase in aspartate transaminase (AST) and bilirubin level was observed in cows receiving glycerin. The study demonstrated that metabolic changes in Simmental breed cows in the periparturient period are dramatic, and an application of glucogenic precursors may improve metabolic efficiency.