Feed allowance optimization for Holstein lactating cows in Sakhalin island musson climate

The aim of the study is to optimize feed rations for Holstein cows in Sakhalin conditions, taking into account the level of milk productivity and the stage of lactation. Research asessed the effectiveness of the animal feeding system at agricultural enterprises and peasant farms on Sakhalin Island, studied the com-position and quality of feed and rations used, and identified the main factors affecting the quality of harvested feed. It was found that the deficiency of leguminous plants in the herbage leads to a low nutritional value of the resulting forage. Analysis of forage grasses showed that they do not provide lactating cows with nutrients, trace elements and vitamins at a sufficient level. It was noted that feed premixes and biological additives are included in the diet without preliminary research and calculations, which leads to their ineffective use. Also, using the “Fodder Rations” software, an example of a ration for cows in the first phase of lactation was developed, providing an optimal combination of feed and biological additives, as well as providing the necessary ratio of fiber, metabolizable energy and protein. The use of the proposed diet helps to improve the metabolism of animals, their biochemical blood parameters, as well as the general physiological state of lactating cows. Optimization of rations taking into account the lactation phase contributed to an increase in potential milk yield by 11–14 %. The use of a balanced diet will lead to an increase in the average annual productivity of cows with a mass fraction of fat in milk of 3.6–3.8 %, protein – 3.0–3.2 %. For feeding lactating cows, high-energy and high-protein voluminous feed is needed. Such feed should contain at least 10 MJ of metabolizable energy and 14–16 % crude protein in 1 kg of dry matter. Supplements should compensate for the possible lack of micronutrients and vitamins in the diet.