Linear Heart Index аt Japanese Quails

Quail egg farming is the most promising sector of the poultry industry in the Russian Federation. Today, many countries of the world are engaged the study of the cardiovascular system of Japanese quails is a relevant research topic. The study was carried out in the experimental research laboratory and vivarium of the Veterinary Medicine Department of Agricultural and Technological Institute of Peoples’ Friendship University of Russia in the period from 2017 to 2021. The aim of the article is to study the Japanese quails’postembryonic heart ontogenesis in connection to the formation of their egg productivity. The article studies the changes in the weight and linear parameters of the Japanese quail’s heart in age aspect, reveals quail’s heart structural features, which contribute to egg productivity. The general structural principles and specific Japanese quails’ heart features have been established. With the help of macro- and micro-preparation, morphometric, histological, stereometric and statistical research methods, for the first time, a detailed comparative assessment of the postembryonic organogenesis of Japanese quails’ heart in postembryonic ontogenesis was studied,the general structural principles were determined, and on the data basis obtained, the critical periods of its development in Japanese quails have been formulated. The established age-related heart characteristics represent a «morphological norm». The need for the scientific use of an integrated methodological approach, including macro- and micro-preparation, morphometry, classical histological examination with subsequent stereometry and digital data statistical analysis, is that the results obtained can serve as a basis for the development of measures to improve Japanese quails’ productive qualities, as well as for their rational maintenance and feeding organization.