Influence of a complex feed additive on the morphological and biochemical parameters of the blood of first-calf heifers during the period of increasing the milk yield

It is known that mineral additives play an important role in increasing the productivity and efficiency of the animal husbanry industry as a whole. The state of the body can be assessed by the content of mineral substances in a blood test. The purpose of the work was to study changes in morphological and biochemical blood parameters in first-calf heifers during the period of increasing the milk yield when they are fed a complex mineral and vitamin feed additive (CMVFA). The study of the influence of feeding the complex mineral and vitamin feed additive in the ration to first-calf heifers during the the period of increasing the milk yield on morphological and biochemical blood parameters has been carried out. The experiments were carried out in 2019–2020 in the OOO Breeding Farm “Valiev” in the Dyurtyulinsky district in the Republic of Bashkortostan on 3 groups of first-calf heifers of Black-and-White breed per 15 heads in each selected by the method of pairs of analogues. The animals of the control group received the main ration (MR) adopted on the farm, the 1st experimental group MR+120 g/head CMVFA according to the recipe No. 1, the 2nd experimental group MR+120 g/head CMVFA according to the recipe No. 2. In the ration of animals of the control group there was a deficiency of basic macro- and microelements. The use of CMVFA as part of the ration of first-calf heifers during the period of increasing the milk yield had a positive effect on the morphological and biochemical parameters of blood. Studies have shown that the use of CMVFA in the rations of first-calf heifers provided the need for minerals and vitamins, accelerating metabolic processes in the body during the most stressful period of lactation, the period of increasing the milk yield. According to the results of biochemical blood parameters, it is possible to esimate the improvement of protein, carbohydrate and mineral and vitamin nutrition in the first-cakf heifers of the experimental groups during the period of increasing the milk yield, which showed their genetic potential more fully and used nutrients more effectively for milk synthesis.