Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>The study concerns the influence of Valopro and Ruprocol fodder additives on the change of the growth energy and formation of meat productivity of Kalmyk bull calves during their nursery from 9 to 18 months of age. The addition of Valopro at a rate of 20 grams and Ruprocol at a rate of 50 grams per head per day to the basic diet during 273 days contributed to a daily gain of 1580–1560 g, which is 200–250 g higher than the control animals. The bull calves of the experimental group used 2.0 % more daily time for eating fodders and 1.6 % less for their chewing, besides, they had less rest standing and moved in a pen, and during the whole experimental period gave 426 kg of absolute gain, or 76 kg more than the herdmates of the control group. The experienced bull calves showed higher resistance to upper respiratory tract diseases, eye diseases, laminitis and hepatosis. During the control slaughter, the body weight and heavy carcasses of bull calves of both groups met the requirements of the current GOST category Super. The hot carcass weight of the bull calves of the experimental group averaged a little more than 362 kg, i.e. 62 kg more than the control group (P≤0.01). Each bull calf gave 11488 rubles profit, which is almost 4.5 thousand rubles more than the herdmates of the control group. Therefore, the latter have almost 5 % lower profitability.</jats:p>