Effects of combined supplementation with plant bioactive lipid compounds and biotin on ruminal fermentation, body condition and energy metabolism in transition dairy cows

The negative energy balance during early lactation often leads to excessive mobilization of body reserves and increases the risk for ketosis. The present study proceeded from the hypothesis that combined supplementation of a commercial blend of plant bioactive lipid compounds (essential oils) plus biotin throughout the transition period could have a positive impact on energy metabolism in dairy cows postpartum, partly, by improving ruminal production of propionate as a precursor for hepatic gluconeogenesis. Thirty five multiparous Holstein -Friesian dairy cows were divided into two groups. The control group (CON; n =16) received a total mixed ration plus individual concentrate feeding (increasing gradually after parturition up to 6 kg/d at peak lactation). The other group received the same diet supplemented with 1.3 g/d plant bioactive lipid compounds and 33 mg/d biotin (PBLC+B, n=19) from day (D)-21 before until D37 after parturition. Assessment of body condition score (BCS) and back fat thickness (BFT), as well as collection of blood serum samples was performed weekly until D58. Samples of ruminal fluid were acquired by stomach tube at D37 and D58. Cows in the PBLC+B group maintained better body condition after calving; BCS was higher than CON at days (D)23, D37 and D44 (P<0.05), and tended to be higher on days D16, D30, D51 and D58 (P < 0.1). Towards the end of the study period, BFT was also numerically higher in PBLC+B cows (P=0.107 at D44 and D51). Serum concentrations of glucose, p-hydroxybutyric acid, non-esterified fatty acids, triglycerides, cholesterol, urea, aspartate transaminase, cholesterol, -y-glutamyltranspeptidase and glutamate dehydrogenase did not differ between groups. Cows in the PBLC+B group showed a faster decrease of serum bilirubin after parturition (P <= 0.05 to CON at D30). Propionate concentration in ruminal fluid was higher in PBLC+B compared to CON at D37 (P <= 0.05) but not D58 after parturition. It is concluded that combined addition of plant bioactive lipid compounds and biotin to the diet of transition dairy cows led to improved ruminal propionate fermentation and decreased loss of body condition postpartum. Differences in serum bilirubin may indicate improved hepatic metabolism in PBLC+B cows. Therefore, a mix of plant bioactive lipid compounds and biotin may ameliorate the metabolic challenges in the transition period of dairy cows. (C) 2017 Elsevier B.V. All rights reserved.