Influence of complex additives on growth, development and reproduction ability of replacement heifers

Recently, the use of various biologically active substances, feed products and feed additives including functional additives, in rearing replacement heifers has been carried out on many dairy cattle breeding complexes and dairy farms. The purpose of the work was to study the eff ect of using complex functional additives Rumenfi t 50 and Rumenfi t 100 in starter compound feeds, used in feeding rations for replacement heifers aged 2 to 6 months, on the growth, development, conformation parameters during the rearing period and reproductive ability of animals. The work was carried out on the basis at the dairy complex Ilkhan LLC in the Cheremshansky district of the Republic of Tatarstan on replacement heifers of Holstein breed. The studies have shown that when rearing replacement heifers up to 6 months of age, the use of complex functional additives Rumenfit 100 and Rumenfit 50 in starter compound feed recipes had positive influence on their growth rate and blood biochemical parameters during the rearing period, and increased the reproductive abilities of replacement heifers. A higher level of profitability when rearing heifers up to 6 months of age (21.4 %) was obtained in the group of heifers receiving the complex additive Rumenfi t 100, which exceeded the profi tability level in the control group by 8.0 abs.% and in the group receiving Rumenfi t 50 by 0.9 abs.%. The highest additional revenue from the “conditional” sale of milk was received from fi rst-calf heifers receiving the complex additive Rumenfi t 100, which was higher by 10,391.04 rubles than the indicator of herdmates which received the Rumenfit 50 additive. When included in the composition of compound feed for replacement heifers during the rearing period, preference should be given to the Rumenfit 100 additive, the use of which has shown higher results.