TDK conference 2017

Dystocia and perinatal calf mortality cause significant economic losses in dairy cattle industry. Despite advanced ultrasound examination procedures, there is no reliable method to estimate the birth weight of calves and a possible dystocia ante partum.

A total of 128 late term pregnant Holstein-Friesian dairy cows have been examined in our study at the Bóly Ltd. dairy farm. In 104 cases, fetal ultrasound measurements could have been performed. During the measurements, the bone-diameter if the fetal metacarpus/metatarsus was measured. We collected further data (insemination/pregnancy data of heifers and cows, the distances between tuber coxae and tuber ischiadicum, maternal weight, calving ease and level of difficulty, birth weight and vitality of the calves).

Excluding twin deliveries (n = 7), 97 fetal metacarpus/metatarsus bone diameter have been analysed in relation to the other parameters. The average Mc/Mt bone diameters were as follows: 2.54 cm ± 0.365 cm (mean ± SD); the calf birth weight was 42.52 ± 4.88 kg (mean ± SD), respectively. A positive and significant (p < 0.00001) association could be detected between the measures of metatcarpus/-tarsus of calves and the birth weight. Establishing a new index number (Mc index = maternal weight (kg) / fetal bone diameter) we could conclude, that the preterm measurement of fetal Mc/Mt bone diameters can have a clinical significance in the estimation of dystocia in cattle.