Bioenergetic and ethological features of the first-calf heifers of different genotypes

The aim of this work was to study bioenergetic and ethological indicators in crossbred first-calf heifers compared purebred heifers. research conducted on the Ukrainian Black-Pied dairy breed first-generation crossbreeds obtained as a result crossing with Brown Swiss breed, well as, Red-Pied Montbéliarde breed. Black-and prevailed over crossbreed indicator milk yield for 305 days lactation by 106.45 218.36 kg, respectively. Accordingly, average daily were also higher 0.35 0.72 kg adjusted 4 % fat content per 0.15 0.16 kg. At same time, 0.08 breeds, breeds. had an advantage 2.04 MJ crossbreeds, while slight 0.06 cost exchange energy (EE). allocated 0.42 0.82 MJ. They rates heat products 0.79 0.25 According index indicator, Black - 0.07 %, trend observed relation productive indicator. 0.001 0.002 1 behavioral reactions, no special differences between found.