PERIPARTURIENT BEHAVIORAL PHYSIOLOGICAL A ND STRAIN REACTIONS IN CATTLE FROM DIFFERENT BREEDS AND THEIR OFFSPRING - EFFECT OF HOUSING CONDITIONS, AGE OF THE ANIMAL AND THE COURSE IF DELIVERY

Results of several projects were use for a comparative investigation o f behavioural physiological and strain reactions in dams kept tethered in the stall (dairy cattle) or group housed (mother cows) during wint ertime and in their offspring affected by the course of delivery under different calving conditions. Nine early pregnant heifers were delive red at term by cesarian section. Studies on cattle scheduled for compa rative assessment of physiological and strain reactions of animals dur ing birth can successfully performed in one and the same big cattle he rd bred and kept in only one experimental station. Great changes in ne ar all systems can be observed during and short after parturition in t he mother and the young as well concerning the circulatory and respira tory function, the blood composition and the neurohumoral system and i ts mediators. Effects of breed, age, gestation length birth course and of sex and maturity of the calf on the reaction of the animals could be established. Relationships between the measures of the mother and t hose of their offspring could be shown in some cases. Some measures we re scattering markedly showing great individual differences and in som e instances individually specificity. Strong correlations between the venous blood pH and peripheral venous cortisol and catecholamine conce ntration could be found meaning causal relationships and synergistic r eactions of the adaptation mechanisms. Long lasting effects of husband ry and housing conditions by means of constitutional traits in mother cows and dairy cows became obvious during the calving period. In the c ase of term cesarian section the same mechanisms as in natural birth w ill be activated although in a stronger way. Components of strain reac tion caused by the passage of the natural birthway damaging the circul atory, respiratory and central nervous system function fail to appear so the calf's adaptation to the new environment can occur more success fully.