[Physiological variables in calves and their significance for vitality and growth].

Calves from the dairy herd and from the mother cow herd and their dams were investigated just after parturition and the calves at the first two days of life and between fifteen and twenty days and than at ninety days of life as well using whole day heart rate and video recording, results of venous blood sample analysis and body growth and health criteria. The great variation of physiological variables in calves can partly be explained by maturity, degree of adaptation, gender, time of day and the birth course. Relationships between physiological variables and the adaptability, body growth performance and the degree of adaptation to specific rearing condition could be pointed out.

[Thyroid hormones in dairy calves after birth and in the first days of life. Amplitude of variation, maternal-fetal relationships and reaction patterns specific to the individual].

Dairy calves and their dams from the dairy herd of the institute were used for this investigation. Calvings were watch carefully and jugular venous blood samples taken immediately after delivery from the cow and the calf and in the calf at 24 hours and at 48 hours of postnatal age as well were analyzed for T4, FT4, T3 and FT3 by luminescence enzyme immunoassay (LEIA). Higher thyroid values in calves than in their dams could be found increasing short after birth and reaching their highest level within 24 hours of postnatal life.

[Adaptation reaction of dairy calves in the first days of life. Effects of type of delivery and individuality of the newborn].

Surveying a calving period of tethered dairy cows, newborn dairy calves of different breeds were investigated just after birth and at 24 hours and 48 hours of their postnatal life as well. Blood samples taken by venipuncture in calves were analyzed for acid-base-balance, hemoglobin, catecholamine and cortisol. Comparing the mean values of the newborns from calvings without assistance, with slight pulling and with heavy pulling, differences could be found only in the first hours of postnatal life between some of them without hemoglobin content of the blood that was of individually specificity and all the time lowest in calves delivered by heavy traction.

[Reactions of heifers in early pregnancy and their offspring delivered at term by cesarean section and in the first postpartum days in a cow-calf operation].

In 11 heifers originating from one mother cow herd and in their offspring delivered by cesarean section heart rate recordings were taken during their staying in the calving box and later on in group housing. Heart rate showed a rhythmicity in accordance with behavioural physiological reactions. The mean heart rate of a 24 hour period in an animal was different between and within the newborn and elder animals.

[The hemoglobin concentration in the blood of dairy cattle of different breeds and their offspring during the peripartum period].

Blood samples taken repeatedly from dairy cows on pasture (50 Holstein-Friesian) and then from 181 cows and their newborn calves within 5 to 10 min after birth were used for measurement of haemoglobin content (Hb). Hb decreased with ongoing lactation and pregnancy, increased several weeks before parturition and reached its highest value shortly after birth. There was some individual, breed and age specificity of Hb in dairy cows.