The aim of this study was to determine the effectiveness of feed additive that contains hop cones, vitamin E, choline, methionine and carnitine in the treatment of subclinical ketosis in transition dairy cows. Twenty multiparous dairy cows with a milk yield > 5000 kg in the previous lactation were used after calving in this experiment. The cows were divided into two groups: control -healthy cow (n = 10) and experimental -cows with subclinical ketosis (n = 10). The subclinical ketosis cows received a feed additive containing ground pellets of hop cones -20 g, alpha-tocopherol -3 g, rumen protected choline -20 g, methionine -20 g and L-carnitine -1 g per head per day for 20 days. Blood samples were collected from the tail (coccygeal) vein before morning feeding on 1 st and 20 th days of experiment. Levels of glucose and β-hydroxybutyrate ketone were determined in blood. Insulin and cortisol were measured in the plasma. Total protein, albumin, urea nitrogen, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured in serum. In the urine, ketone bodies were detected. The results obtained showed that the subclinical ketosis cows before treatment had a β-hydroxybutyrate level decreased by 36% and also glucose level was lower than healthy ones. After treatment, levels of glucose, insulin and cortisol increased by 31 %, 22 % and 15% respectively in subclinical ketosis animals. The feed additive also has a hepatoprotective properties as serum albumin level increased, while urea nitrogen level decreased in comparison to the healthy cows. However, these changes are superimposed on the natural physiological changes that occur in the blood parameters during the first few weeks after calving, as the healthy cows that did not receive feed additives showed unidirectional changes but less pronounced. On conclusion, the proposed feed additive can be used in the treatment and prevention of subclinical ketosis.

The purpose of the work was the correction rumen fermentation in the transition cows to prevent metabolic disorders. For the experiment, two groups of Ukrainian dairy black-and-white breed cows were formed, 10 animals per group. The experiment lasted 3 weeks prepartum and 3 weeks postpartum. Animals received a balanced diet, which consisted of haylage, silage, barley, wheat, corn, soybean meal, salt, mineral and vitamin premix. The first group was the control. To the diet of second group 300 mg of α-tocopherol acetate (0.6 g of Rovimix E-50) and 1 g/kg of dry hop cones per kg of dry matter was added. Before calving, the tested feed additive reduced the concentration of peroxide oxidation products in the cows blood (P<0.05) without affecting other parameters. Changes that are more significant detected after calving. A decrease in the concentration of lipid hydroperoxides (P<0.05), TBARS (P<0.05), and beta-hydroxybutyrate (P<0.05) were observed in the blood of the cows of the experimental group. Therefore, the addition into diet of transition cows of α-tocopherol and hop cones inhibits the lipid peroxidation and reduces the ketones formation. So, this feed supplement can be used to prevent ketosis and steatosis in cows.

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.

It is known that ionophoric antibiotics regulate ruminal fermentation, improve the utilization of feed protein, and prevent the occurrence of ketosis and steatosis in ruminants. Ionophoric antibiotics and β-acids of hops have a similar spectrum of biological activity, that is, they inhibit the vital activity of most gram-positive microorganisms of the rumen. Bacteria, like other living organisms, need vitamin E as an active antioxidant for cell membranes. The toxicity of tocopherol is very low, so adding it to the diet of ruminants in larger quantities can stimulate celluloselytic rumen bacteria and compensate for the negative effect of ionophores on fiber breakdown. Since rumen bacteria break down a significant part of dietary choline, methionine and carnitine, ruminants must receive them in a protected form, so their influence on rumen fermentation is insignificant. Three groups of cows of the Ukrainian dairy black-spotted breed with milk yields of 5 or more thousand kg during the previous lactation were formed: with signs of clinical ketosis — 4 animals; with subclinical ketosis — 5 animals and clinically healthy — 5 animals. For a month, cows with ketosis were given a treatment supplement containing crushed granules of hop cones (20 g), vitamin E (3 g), and rumen protected choline (50 g), methionine (20 g) and carnitine (1 g). Clinically healthy cows were used as control. In the blood of cows with subclinical ketosis, the additive increased the concentration of glucose and decreased the concentration of β-hydroxybutyrate, these indicators were within the normal range. In cows with symptoms of clinical ketosis, using of the feed additive also reduced the concentration of β-hydroxybutyrate (P<0.01), but it was still higher than normal. In sick cows, amylolytic and lipolytic activity was lower than in healthy cows (P<0.05–0.01). Celluloselytic activity was lower only in cows with clinical ketosis. The proteolytic activity of rumen content changed in the opposite way; it was higher in sick cows (P<0.05–0.01). This is a consequence of the increase in the number and activity of hyper producing ammonia bacteria in the rumen, what is characteristic for ketosis. After treatment of cows with subclinical ketosis, the celluloselytic and amylolytic activities in the rumen fluid were equal to the corresponding indicators of healthy cows, and the proteolytic activity was even slightly lower (P<0.05) than in the control group. Treatment of cows with clinical form of ketosis was not as effective, although the general trends remained. During subclinical and clinical ketosis, a greater amount of ammonia was found in the rumen fluid (P<0.05–0.01), because of higher proteolytic activity. In both forms of ketosis, the concentration of volatile fatty acids in the rumen decreased, and the concentration of lactate increased (P<0.05–0.01). After the treatment, these indicators in cows with subclinical ketosis approached the healthy animals, while the condition of cows with clinical ketosis improved, but the concentration of ammonia continued to differ from healthy animals.