Studies of morphological and morphometrical particularities of rennet of newborn calves with different degree of antenatal hypotrophy were realized in the conditions of the Republic of Belarus. Scientific-and-production researches were spent in 2007 - 2008 on the basis of agricultural production co-operative Dembrovo (Shchuchinskij district, Grodno area, Belarus), agricultural production co-operative Okhovo (Pinsk district, Brest region, Belarus) and research laboratory of Grodno State Agrarian University (Belarus). For an estimation of morphofunctional maturities there were used 165 1-day old calves. Research results showed that in the studied calves the basic indexes of glanderous apparatus of rennet proved the different degree of morphofunctional immaturity. In calves with hypertrophy in the first days after birth there stated an active morphogenesis of all cytological components of rennet

Realized review of research works showed that pathologic behavior of ulcerous abomasitis of calves, its preventive maintenance and treatment, as well as the functional status of liver of heart of sick calves require more thorough analysis in the conditions of the Republic of Belarus. Research results proved the perspective direction of experimental investigation of ulcerous abomasitis of calves by means of ulceration of mucous membranes of fundic portion of fourth stomach y means of derangement of circulatory dynamics of organ portions. The proposed experimental model made it possible to obtain animals with pathology similar to the main clinical, biochemical and morphofunctional parameters with such unprompted pathology. Results of realized experiment on reconstitution of ulcerous abomasitis at 13 calves were presented. Indexes of total clinical blood analysis at different stages of experiment, white blood cell differential, biochemical blood indexes, and indexes of abomasal content of experimental calves were presented