DIAGNOSIS OF PERINATAL WELL-BEING OF DAIRY CALVES
At present, in veterinary practice the main emphasis should be placed on prevention of asphyxia of calves at birth since instruments suitable for a reliable clearing of respiratory passages and for the maintenance of this state and for artificial respiration of calves in the field are not yet widely available. The most important breeding objective is to reduce the number of calving assistance required. This is even more important, since calving assistance in itself may result in a shift of the calf's acid-base balance to acidosis. In case of difficult calving, the mode (traction or caesarean section) and time of calving assistance (within 2 h after rupturing the foetal sacs /Held 1983/) should be chosen with regard to profitability factors and in a manner which would allow the least possible shift of the calf's acid-base balance towards acidosis. Before applying traction, the measurements of the soft birth canal should always be considered when dilatation of the soft maternal passages is not sufficient they must be expanded non-surgically or surgically (episiotomy lateralise) and obstetric lubricants should be used to avoid tractions longer than 2 to 3 minutes (Szenci 1985b, 2003) and rib and vertebral fractures due to excessive traction (Schuijt 1990). If a prolonged traction is expected, Caesarean section should be carried out to save the calf and to prevent injuries to the maternal birth canal. Recent studies have shown that before making a decision as to the mode of calving assistance in an animal hospital, the results of acid-base balance measurements from blood samples should be considered. The routine use of complex treatment of calves (initiation of respiration, intensive rubbing of the newborn calf especially the neck and shoulder region with a dry large towel cloth, oxygen supplementation, compensation of acidosis by bicarbonate treatment) born with severe asphyxia may reduce the postnatal calf losses (Szenci 2003, Mee 2009). In addition to an adequate therapy, particular attention in the case of calves with asphyxia should be paid to the ingestion and absorption of sufficient amounts of colostrums (Eigenmann et al 1983b, Besser et al 1990), since the lack of colostrum uptake is accompanied by an increased susceptibility to gastrointestinal disorders (Besser and Gay 1994). In case of diarrhoea or pneumonia early diagnosis and immediate adequate treatment is needed to decrease the rate of calf morbidity and mortality (Smith 2009).
Key words: dairy calf, cow, diagnosis of prenatal well-being