Effect of propylene glycol on blood metabolites, ruminal and productive parameters of growing-finishing lambs

Background. Propylene glycol has been used successfully since the 1950’s for him acute and prophylactic treatment of ketosis in dairy cows however; its use has been poorly evaluated in beef cattle and meat sheep. Objective. Evaluate the effects of different doses of propylene glycol on the productive parameters, blood metabolites and ruminal parameters in fattening lambs. Methodology. Twenty lambs 14.70 ±0.57 kg of weigh, 2 months old, males and Katahdin-Black Belly breed, were randomly assigned to one of four treatments, a control mixed ration and an experimental diet with three different levels of propylene glycol: 1.0, 1.5 and 2.0 g/20 kg live weight/day. The effects of propylene glycol on blood metabolites, ruminal and productive parameters were assessed. Results. Propylene glycol supplementation did not affect (P>0.05) glucose, total lipids, triglycerides and cholesterol concentration as well as increased (P<0.05) the concentration of beta hydroxybutyrate. In addition, its inclusion resulted in an increase in pH and protozoa population and in a decrease of reductive activity (P<0.05). No effect was observed (P>0.05) on feed intake, weight gain and feed conversion ratio of lambs but carcass yield was improved without increasing the feeding cost of production. Implications. Propylene glycol is a viable option as an energy source in fattening lambs. Conclusion. Inclusion of PPG increased the pH and the population of ruminal protozoa, reduced the formation of ketone bodies and improved the carcass yield of lambs without increasing the meat production cost.