@article{Hutsuliak_2020, title={Adaptation plasticity of holstein cows of different age with extended and long-term lactation function}, url={https://www.snaubulletin.com.ua/index.php/ls/article/view/252}, DOI={10.32845/bsnau.lvst.2020.4.5}, abstractNote={<p><em>According to the results of our study, it was found that Holstein cows of different ages during lactation, which lasted more than 600 days and long lactation (more than 900 days) were characterized by a fairly low index of adaptation. During long lactation, cows of group I did not have high adaptive properties, as the adaptation rate was negative and averaged 16.1 units, which was more than the value of cows of group III (control) by 2.5%, and animals of group V - at 19.3% (P &lt;0.001). According to the function of lactation, which lasted more than 600 days, cows of III (control) group in the third lactation had a significantly low rate of adaptation, averaging -32.9 units. This value was higher than the group by 27.4% (P &lt;0,05). But the lowest value of the adaptation index was in cows of group IV in the fourth lactation, the average value of which was -33.9 units, which was higher than the value of group I by 29.5% (P &lt;0,001). Lactation that lasted more than 600 days and lactation lasting more than 900 days in experimental Holstein cows was the result of low reproductive function, so they lost an average of 1.06 - 2.3 heads of offspring. Holstein cows lose from 3501.8 to 4320.7 kg of milk during long lactation and 5186.4-6284.4 kg of milk during a long lactation period. Compared with lactation, which lasted more than 900 days, the loss of milk during lactation, which lasted more than 600 days in cows, is 1.48–1.76 times greater. In Holstein cows during lactation, which lasted more than 600 days and lactation function, which lasted more than 900 days, regardless of their age, the balance between the body and the environment is significantly disturbed, as indicated by the negative value of the adaptation index.</em></p&gt;}, number={4(43)}, journal={Bulletin of Sumy National Agrarian University. The series: Livestock}, author={Hutsuliak , Hanna}, year={2020}, month={Dec.}, pages={33-37} }