Correction the blood biochemical parameters in transition dairy cows by hop cones and vitamin E supplement

Abstract

In the prevention and treatment of cow ketosis, the regulation of glucose and fatty acids is the main focus, while ammonia intoxication is largely ignored. The intensity of formation of the rumen ammonia can be reduced by ionophore antibiotic monensin. Hop cones contain a number of biologically active components including phytoionoрhores: prenylated polyphenols lupulon, humulon and their derivatives. Therefore, hop cones can be considered as a potential substitute for antibiotics-ionophores. Vitamin E, fed to ruminants in large quantities, stimulates the cellulosolytic bacteria of the rumen. Accordingly, co-feeding cows with hops and vitamin E supplements can reduce ammonia formation without inhibition the carbohydrate fermentation in the rumen. The experiment used two groups of dry Ukrainian dairy black-and-white breed cows with productivity 6–7 thousand kg of milk for previous lactation, 10 animals per each group. The trial was performed during the last 3 weeks of dry period and the first 3 weeks after calving. Animals were fed a standard balanced diet containing: grass silage, corn silage, barley grain, corn grain, soybean meal, molasses, salt, mineral and vitamin premix. The first group was the control. The diet of second group was supplemented with 300 mg of α-tocopherol acetate (0.6 g of Rovimix E-50) and 1g of dry hop cones per kg of DM. Prior to calving, the tested feed additive reduced the concentration of lipid peroxidation products (P < 0.05) in the blood plasma without affection other parameters. More significant changes were detected after calving. An increase in glucose concentration (P < 0.05), triacylglycerol (P < 0.05), cholesterol esters (P < 0.05) and a decrease in the concentration of NEFA (P < 0.05) were found in the blood of cows of the experimental group in a week after parturition. One month after calving, differences between control and experimental blood plasma parameters were significantly less pronounced. Therefore, addition of 300 mg of α-tocopherol acetate and 1 g/kg of dry hop cones per kg of dry matter of the diet during the transition period stimulates liver glucose synthesis and reduces the rate of fatty acid release from adipose tissue. The specified feed additive can be used to prevent metabolic disorders in early-lactation dairy cows.