Prevalence and degree of ketosis in Holstein cows in breeding conditions

The purpose of research is to study the distribution and degree of manifestation of ketosis in freshly calved Holstein cows. The study was carried out during 2022 at the Bugry breeding dairy farm in the Leningrad Region. The object of the study was freshly calved Holstein cows in the transit period and the period of milking. Cows are kept loose. Milking was done three times a day. Water was available in plenty from automated drinking bowls. Animals are fed throughout the year with a complete monofeed, which includes: silage, compound feed, mineral supplements, barley, meal, bagasse, corn, molasses, soybeans, salt, premix, hay. Cows are kept in stalls all year round. In total, the farm has about 4,000 heads of cattle, of which 1,047 are cows, the calf yield is 85 %. The milk yield per animal is 11,251 kg with an average protein content of 3.11 % and fat content of 3.59 %. The diagnosis of ketosis was made taking into account the main indicators, as well as the results of a biochemical rapid blood test using an electrochemical analyzer. The study was conducted on the 5th and 15th days after calving. In 68 % of cases, subclinical ketosis was diagnosed on the 5th day after calving in cows of the 1st-3rd lactation. Acute ketosis was recorded in 9 animals, which is 0.86 % of all examined cows. The incidence of ketosis on the farm is 8.6 %. In animals of the 1st-3rd lactation, ketosis mainly occurs in a subclinical and moderate form, and in cows of the 3rd-5th lactation an acute form of the disease is typical. Clinical (moderate) and acute forms of the disease are recorded more often in late autumn and winter. Subclinical ketosis was recorded in the herd 5.5 times more often than acute and moderate forms of ketosis. Seasonal dynamics of the disease have been observed. Subclinical ketosis was recorded throughout the year, but the peak incidence was detected in April-May, as well as in August.