Pulmonary gas exchange in heifersand milk productivity of firstborn cows of the simental breed of the Precarpathians of different constitution types

The results of research on pulmonary gas exchange in heifers and milk productivity of Simmental firstborn cows of Precarpathians of different types of constitution, which were evaluated according to the physiological and selection index developed by us, are presented. The control group included heifers and firstborn cows with a low physiological and selection index – a narrow-bodied type, and the experimental group, respectively – with a high physiological and selection index, wide-bodied type. In terms of depth of breathing, pulmonary ventilation, oxygen consumption, carbon dioxide excretion, total energy and heat production, individuals of the broad-bodied type in postnatal ontogeny significantly outnumbered their narrow-bodied counterparts. The research results show that the yield of milk per lactation in the first-born cows of the experimental group was higher than that of the control counterparts by 18.29 %. The content of fat and protein in the milk of the cows of the experimental group was higher, compared to the control analogues. Ultimately, the output of milk fat and protein in the first-born cows of the experimental group was also higher than in the control counterparts. Thus, first-born cows of the Precarpathians  Simmental breed of the wide-bodied type had a higher index of quantitative and qualitative components of milk than their counterparts of the narrow-bodied type. According to indicators of gas-energy exchange in postnatal ontogeny, wide-bodied animals (experimental group) significantly outnumber narrow-bodied counterparts (control group). This indicates that the animals of the experimental group have a much more intensive metabolism than the control counterparts. The indicators of milk productivity in the cows of the experimental group were higher than those of the counterparts of the control group. According to the main indicators of pulmonary gas exchange and milk productivity, animals of the wide-bodied type prevailed over their narrow-bodied counterparts by 10‒12 %. Pulmonary ventilation, oxygen consumption and carbon dioxide excretion, the amount of energy in animals of the wide-bodied type was higher by 11‒13 % compared to the animals of the narrow-bodied type. Milk productivity in first-born cows of the wide-bodied type was 18.29 % higher compared to the analogues of the narrow-bodied type.