Balancing ration of dairy cows on calcium, phosphorus and iron indices for milk production and exchange processes in the organism
O.I. Skoromna, M.F. Kulik, T.O. Didorenko
Minerals are required for normal functioning of basically all biochemical processes in the body. A number of macro and micro minerals have been shown to be essential for animals. Providing adequate amounts of essential minerals to meet animal requirements is critical to maximizing productivity and health of cattle. Dietary requirements are a function of the metabolic requirement and endogenous or inevitable losses of a particular mineral and efficiency in which a mineral is absorbed from the diet. Requirements for most minerals are not constant, but are affected by a number of dietary and physiological factors that affect either absorption or metabolic demand. Physiological factors, that affect requirements of certain minerals, include genetics, age, sex, type of production (maintenance, growth, reproduction, and lactation), and level of production. Dietary factors usually affect mineral requirements by altering absorption of mineral from the gut. Mineral requirements in NRC and other publications are actually estimates of requirements. Generally, the two sources of minerals include natural feeds (forages and grains) and mineral supplements to balance the minerals present in the forages and grains. For the dairy cow, the major minerals (macrominerals) required are calcium, phosphorus, magnesium, potassium, sodium, chlorine, and sulfur. Minerals required in much smaller, trace amounts (microminerals) include iodine, iron, cobalt, copper, manganese, zinc, and selenium. Whether the requirement for a mineral is large (measured as a percent of dry matter) or small (measured in ppm), the proper level must be fed to achieve optimum performance and herd health. The literature sources concerning the balancing of dairy cow mineral nutrition on the dry matter substance of the diet have been analyzed, and we have proposed a new principle of balancing based on the need for milk formation and metabolic processes in the body. The comparative estimation of these criteria on the indicators of milk allocation in% from the consumed quantity of minerals and usage in% on exchange processes in the same comparison is given. The need for calcium involves the presence of calcium in 1 kg of milk, which is 1.2 g, as well as the allocation of milk with milk in daily nutrition, the need for milk formation. Daily hopes of milk are taken from 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 36 and 40 kg for cows weighing from 400 to 700 kg. With such a gradation of the daily milk yield, the level of activity of metabolic processes with the participation of calcium will also be different, so at 12 kg of daily allowance this level is taken for 1, and at 14 kg it will be 1.16, respectively, at 16 kg - 1.18, and etc., and at 40 kg - 3.33. The principles of balancing the needs phosphorus for cows of various capacities are based on mineral digestibility coefficients, its amount in daily milk yield and daily milk necessary for the formation, determined an increase of 100 times the phosphorus content in the daily milk yield and dividing by a factor of assimilation. The need for phosphorus metabolism in the body is determined by increasing its content in mobile forms in muscle tissue and various liquids yield at 1.16 to 14 kg, with a daily yield of 14 kg at 1.18, while the yield of 40 kg - 3.33 . The total phosphorus requirement for cows of various productivity includes the daily need for milk formation and metabolic processes in the body. The principles of balancing the iron in the diets of dairy cows justified coefficients mastering iron content of milk daily milk yield (mg) and muscle tissue, blood and other body fluids, and hence the formation of the daily requirement of milk (mg) and the metabolic processes in the amount of is a total need (mg).