Abstract:

The article deals with the results of the microelements content in the soil-feed-animal system. The analysis of farm soil 1 showed that the total cobalt content was 6.8; copper – 34.7; zinc – 25.4; manganese – 70.6; iron – 198.2 mg/kg. The content of mobile forms of copper and cobalt in soils was 8.5 and 3.6 mg/kg. In farms 2 and 3, the total cobalt content was 6.4 and 5.9; copper – 33.9 and 23.4; zinc – 27.9 and 24.8; manganese – 83.3 and 215.8; iron – 179.4 and 145.9 mg/kg, respectively. The content of mobile forms of microelements in soils has been reduced, with the exception of copper, lead and nickel. Thus, the results of searches of the microelement composition of the soil in the experimental farms, found their impoverishment on cobalt, zinc and manganese. Cadmium is present in all tests of soil samples. Analysis of the fodder of all three farms showed that the copper content was less in the beets, in cereals and silage it is established as its deficiency, and excess, in straw and hay – excess. Cobalt was less in fodder beets, hay, straw and cereals, except in wheat and silage. More manganese was found in beet, hay, straw, less in cereals. Less zinc was in the hay and cereals, more – in silo and straw. The iron content was less in hay, silage, barley and rye, but more – in beet, straw and oats. The analysis of rations showed that the supply of macroelements (calcium and phosphorus) was insufficient (62.0–78.2 and 49.4–57.4%). Along with all rations there was an excess of magnesium (126.9–183.2%) and potassium (186.9–188.0%). The provision of the ration with cobalt and zinc was 25.7–71.8 and 33.6–75.1%, with copper – 21.2–116.1%. In 1 kg of feed dry matter was a low content of cobalt – 0.15–0.29 mg (optimal 0.5–0.7 mg), zinc – 13.6–21.5 (40 mg), manganese – 21.3–51.8 (40 mg), excessive copper – 8–8.7 mg (7 mg), iron – 146.5 – 268.9 mg/kg, with the optimal 60 mg. In feed rations there is an insufficient amount of vitamin D (8.9–14.1% of demand). Subclinical course of osteodystrophy in cows is manifested by loss of shine and ruffling of the hairline, moulting, decreased skin elasticity, alotriophagia, hyporexia, anemia of the conjunctiva; in blood – a decrease in cobalt up to 0.24 ± 0.01 μmol/l, copper – up to 13.4 ± 0.11, manganese – 2.1 ± 0.03, zinc – 14.5 ± 0.13 μmol/l (15–23 μmol/l). In addition to the changes described above, thinning and partial lysis of the last pair of ribs were observed, resorption of the last 2–3 caudal vertebrae, partial deformation of the spine, convexity of the ribs, overgrowth and deformation of the hoof horns. In cows with subclinical course of osteodystrophy, the total calcium content was reduced in 18.9% (2.1–2.9 mmol/l, 2.4 ± 0.02), phosphorus in 5.7% of animals (1,2–2.2 mmol/l, 1.7 ± 0.02). Sick cows with hypocalcemia were diagnosed in 95.0% (1.95–2.40 mmol/L, 2.2 ± 0.05), which was combined with hypophosphatemia in 35.0% of cows (1.1–1.9 mmol/l 1.6 ± 0.07). So, found that the main causes of osteodystrophy in barn feeding cows were a low content of vitamin D, calcium, phosphorus, and also cobalt and zinc in rations.

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