D-vitamin status of cattle depending on the conditions of detention and physiological state

• Main Authors: L. L. Yuskiv, V. V. Vlizlo, N. R. Motko
• Format: Article
• Language: English
• Published: Stepan Gzhytskyi National University of Veterinary Medicine and Biotechnologies Lviv 2019-12-01
• Series: Науковий вісник Львівського національного університету ветеринарної медицини та біотехнологій імені С.З. Ґжицького: Серія Ветеринарні науки
• Subjects: cows, vitamin d3, metabolism, blood, 25-hydroxycholecalciferol
• Online Access: https://nvlvet.com.ua/index.php/journal/article/view/3872

The article contains data on the content of the active metabolite of vitamin D3 – 25-OHD3, the concentration of calcium, phosphorus, magnesium and the activity of alkaline phosphatase in the blood of lactating cows in different periods of keeping. The experiment was performed by the method of periods on the cows-analogues for the 4th month of lactation. Cows are divided into three groups of five heads, each depending on the sampling period: winter stall (January), summer pasture (July) and autumn stall (October) for one year. The blood for tests was collected from the jugular vein before morning feeding in winter-stall, summer-pasture, and autumn-stall hold periods. The composition and nutrition of the diets of cows were also analyzed. Changes in the content of 25-OHD3 in the blood of cows were determined depending on the season and conditions of keeping. The lowest level of 25-OHD3 was in the winter-stall holding period and was 22.38 ± 3.58 nmol/l and the highest was in the summer pasture. In the autumn-stall period, the level of 25-OНD3 decreased relative to the summer pasture, but was higher than in the winter-stall (P < 0.05). The total calcium content of the serum of cows was highest in the summer pasture and winter-stallion periods and was, respectively, 2.96 and 2.90 mmol/l. In the autumn-stalling period, the total calcium content decreased and was significantly lower compared to the summer pasture period (P < 0.05). Changes in the total calcium content of cows' blood during different retention periods were due to changes in its fractions. The activity of total alkaline phosphatase and its bone isoenzyme in the blood of cows at 4 months of lactation varied in contrast to the content of 25-OНD3.