Fetal metacarpal/metatarsal bone thickness as possible predictor of dystocia in Holstein cows

Abstract

Dystocia and perinatal calf mortality cause significant economic losses in the dairy cattle industry. Despite advanced ultrasound examination procedures, there is no reliable method to estimate the birth weight of calves in order to predict, prepartum, the risk of dystocia. The aim of this study was to predict calf birth weight and dystocia based on transrectal ultrasonographic (TRUS) examinations in late-term Holstein heifers and cows. Therefore, TRUS examination was performed on 128 animals that were between 265 and 282 d of gestation to measure the bone thickness of the fetal metacarpus (MC) or metatarsus (MT). Fetal TRUS measurements were successful in 104 cases. Excluding twin deliveries, 97 fetal MC/MT bone thicknesses were measured and the mean (±SD) MC/MT thickness was 2.54 ± 0.37 cm. A novel index, the metacarpal/metatarsal index [MCTI = maternal body weight (kg)/fetal MC or MT thickness (cm)], was also calculated to study its association with calving ease. The average MCTI was 257.3 kg/cm in the studied population. A lower MCTI was associated with the risk of dystocia with an odds ratio of 2.074 that was not significantly different from 1 (95% confidence interval: 0.002-11.104). Fetal presentation, fetal age, fetal sex, body condition score of the dam, age of dam, and intercoxal and interischiadic distances were not related to dystocia. A fair phenotypic correlation (0.226) was found between MC/MT thickness and calf birth weight. The genetic correlation between MC/MT thickness and calf birth weight was 0.235. Our results indicate that late-term measurement of the fetal MC/MT bone thickness by means of TRUS examination augmented with the MCTI may have clinical significance in the prediction of dystocia in Holstein cattle. Because the odds ratio for dystocia based on MCTI determination was not significant, the applied technique should be improved based on further studies on prepartum TRUS examinations combined with dam pelvic measurements.

Effect of different parities on reproductive performance, birth intervals, and tail behavior in sows

“…It is well recognize that in the sow most stillbirths occur intrapartum as a result of dystocia and the delayed expulsion of the litter [28]. There are substantial data on stillbirth rates in sows [29,30]. The results of this experiment suggest that the number of stillborn is less than 1 in most parities and it is difficult to regard them as dystocia.…”

Perinatal rib fractures in 18 calves delivered from Holstein dams

“…Since four out of six calves were male and half of their dams were primiparous, it may be due to feto-pelvic disproportion ( Mee, 2008 ). Dystocia scoring used in this study was developed to evaluate the difficulty or ease of deliveries from the viewpoint of farm workers ( Mee, 2008 ; Vincze et al., 2018 ). Dystocia scoring may not necessarily indicate pressure in the birth canal on neonates at delivery.…”

“…Farmers were interviewed retrospectively regarding presentation at birth, degree of calving difficulty, and sale price (yen) at the Chiba livestock market of the rib fractured calves that were sold after the diagnosis of rib fractures. The conditions of calving were graded by the first author on a 4-point scale ( Vincze et al., 2018 ) as follows: eutocia (unobserved and unassisted calving), light dystocia, mild dystocia, and severe dystocia. Some farmers used a pocket block and tackle in dystocia.…”

Managing bovine dystocia – an age‐old problem

“…enable the development of clear SOPs, rather than the vague 'if you think the calf is too big, call the vet' advice that is often given to farmers. Regrettably, measurements of calf leg diameter and maternal pelvis, 4,5 while attractive in theory, have not proved their value for guiding decision making in the field. Feto-maternal disproportion is essentially the interplay between dam genetics, dam environment and sire genetics/selection.…”

“…Estimated breeding values for dystocia should also be routinely used for sire selection.• Routine monitoring of body condition score should be performed before the start of calving to ensure dams are in optimal body condition.enable the development of clear SOPs, rather than the vague 'if you think the calf is too big, call the vet' advice that is often given to farmers. Regrettably, measurements of calf leg diameter and maternal pelvis,4,5 while attractive in theory, have not proved their value for guiding decision making in the field.…”