Relationships of peri-partum, plasma concentrations of progesterone, oestrogens and 13,14-dihydro-15-ketoprostaglandin F2alpha in heifers and of anatomical measurements of dam and calf with difficulty of calving in early-bred Hereford x Friesian heifers

Association between dam and calf measurements with overall and fetopelvic dystocia in Holstein heifers

We investigated the relationship between dam's pelvic and calf's dimensions with dystocia due to fetopelvic disproportion in the Holstein breed and estimated risk factors and dystocia probability. For this purpose, external pelvic measurements were performed in 402 heifers 15 ± 11 (1-38) days ante-partum and specific conformation measurements were obtained from their calves 1.7 ± 1.2 post-partum. Dystocia was defined as the inability of the heifer to complete parturition spontaneously within 120 min after the appearance of the amnion with normal presentation, position and posture or as having definite obstetrical obstacles within 60 min. Overall and fetopelvic disproportion dystocia incidence was 10.4% and 5.2%, respectively. Heifer measurements mainly influenced overall dystocia, whereas calf conformation was related solely with fetopelvic dystocia. Specifically, heifers with a small pelvis (hip width <49.95 cm, pelvic inlet area <333.2 cm2, pelvic volume <7799.2 cm3) had 2.8 to 3.5 times greater incidence of overall dystocia (19.0-20.8%) compared to heifers with a larger pelvis (incidence of 7.0-7.6%). Regarding calf factors, sex (male calves), body weight, chest circumference and fetlock joint circumference significantly increased the odds of experiencing dystocia due to fetopelvic disproportion compared with female, lighter or smaller calves. In a backward elimination model with independent variables treated as continuous, an area under the ROC curve of 0.66 regarding the prediction of overall dystocia based on heifer pelvic length, and of 0.64 for the prediction of fetopelvic dystocia based on fetlock joint circumference was found. The combination of the two variables in one model improved the ROC area to 0.71 regarding dystocia due to fetopelvic disproportion, reaching acceptable level of discrimination. Our findings indicate that dystocia due to fetopelvic disproportion in heifers is mainly influenced by the fetal side. Additionally, the estimation of pelvic dimensions of the dam before parturition and specific conformation characteristics of the calf during parturition, especially fetlock joint circumference, could aid obstetricians and herdsmen regarding dystocia probability and parturition surveillance.

Methods and on-farm devices to predict calving time in cattle

In livestock farming, accurate prediction of calving time is a key factor for profitability and animal welfare. The most accurate and sensitive methods to date for prediction of calving within 24 h are the measurement of pelvic ligament relaxation and assays for circulating progesterone and oestradiol-17β. Conversely, the absence of calving within the next 12-24 h can be accurately predicted by the measurement of incremental daily decrease in vaginal temperature and by the combination of pelvic ligament relaxation and teat filling estimates. Continuous monitoring systems can detect behavioural changes occurring on the actual day of calving, some of them being accentuated in the last few hours before delivery; standing/lying transitions, tail raising, feeding time, and dry matter and water intakes differ between cows with dystocia and those with eutocia. Use of these behavioural changes has the potential to improve the management of calving. Currently, four types of devices for calving detection are on the market: inclinometers and accelerometers detecting tail raising and overactivity, abdominal belts monitoring uterine contractions, vaginal probes detecting a decrease in vaginal temperature and expulsion of the allantochorion, and devices placed in the vagina or on the vulvar lips that detect calf expulsion. The performance of these devices under field conditions and their capacity to predict dystocia require further investigation.

Extraction methods in bovine obstetrics: comparison of the demanded energy and importance of calf and traction method in the variance of force and energy

In a previous study we could demonstrate that in terms of the required forces alternate traction is preferable to simultaneous traction for the obstetrical delivery of calves. The aims of this study were to examine the required energies for delivery of calves and to compare the effects of the factors of calf and traction method on the forces and energies required for the delivery. In a biomechanical in vitro model 12 stillborn Holstein-Friesian calves were pulled through the pelvic specimen of a cow at a controlled speed using two electric motors. Traction was applied simultaneously (ST) to both legs or alternately (AT) to one leg at a time to advance it 10 cm (AT 10) or 5 cm (AT5). Energies on each limb were measured digitally using load cells. The lowest energy for the entrance of the elbows in the pelvis was necessary using AT10 (19.9 ± 7.2 kJ, P < 0.05). In contrast, for the entrance of the chest, AT10 (104.9 ± 24.7 kJ) demanded 9% (P < 0.01) and 16% (P < 0.001) more energy than AT5 (96.7 ± 21.0 kJ) and ST (90.5 ± 24.9 kJ), respectively. Simultaneous traction tended to be better than AT5 (P = 0.09). Variance component estimates revealed that the factor calf contributed the main effect to the emerging forces and required energy. The traction method was responsible for up to 13% of the variance in most of the cases, but it accounted for 42% of the variance regarding the forces on the lower limb as the chest entered the pelvis. Based on these findings, the decision of the clinician whether or not to perform a manual traction should depend mainly on the calf. However, when such a decision has been made, alternate limb traction, 10 cm at a time, should be used until both elbows have entered the pelvis and a simultaneous traction should then be applied to complete extraction of the chest.

Clinical signs and hormonal changes in dairy heifers after induction of parturition with prostaglandin F2 alpha

Parturition was induced in 12 dairy heifers with prostaglandin (PG) F2 alpha about 2 weeks before the expected time of calving. Eight animals gave birth after two injections (group 1), three animals needed more than two injections (group 2) and one animal (cow no. 740) required one injection. All animals in groups 1 and 2 had retained foetal membranes and the time needed to induce parturition was 59 +/- 7 and 149 +/- 10 h, respectively. As cow no. 740 did not have retained foetal membranes and calved 24 h after one PGF2 alpha injection, it was excluded from the results. Udder distension and relaxation of the pelvic ligaments could predict the calving to within 12 h. Furthermore, the pre-calving drop of body temperature could predict the time of parturition to within 16 h. The total white blood cells and polymorphonuclear cells were at their highest values on the day preceding parturition whereas mononuclear cells had a tendency to increase 3 days after calving. Increased levels of haemoglobin were found at the time of parturition, whereas, plasma-calcium levels significantly decreased after parturition (P < 0.001). Progesterone levels markedly decreased after the first PGF2 alpha injection and reached 2 nmol/l at the time of parturition. Plasma levels of oestradiol-17 beta reached the peak at the time of parturition, whereas, the highest levels of the PGF2 alpha metabolite and cortisol were recorded 16 h after calving.

Relationship of maternal plasma progesterone and estrone sulfate to dystocia in Holstein-Friesian heifers and cows

Thirteen primiparous and 41 multiparous Holstein-Friesian cattle were used to study the relationship between maternal plasma progesterone (P4) and estrone sulfate (E1S) concentrations and the prevalence of dystocia. The calvings in 4 heifers and 30 cows were normal (eutocia), while the calvings in 9 heifers and 11 cows were difficult (dystocia). Neither the concentrations of P4 nor E1S were different between the groups with eutocia and dystocia from days 90 to 270 of pregnancy. However, a few days prior to parturition, eutocial cows and heifers showed a sharp decline of plasma P4, while dystocial cattle did not show such a remarkable decline of P4 concentration. Plasma P4 levels in dystocial cows a few days antepartum were significantly higher than in eutocial animals (P<0.05 or P<0.01). Prepartum E1S concentrations were significantly lower (P<0.05) in dystocial than eutocial cattle during the prepartum period from days 6 to 1 in heifers and from days 3 to 1 in cows. These results suggest that insufficient production of E1S and delayed regression of the corpora lutea are possible causes of dystocia in cattle.