Variables associated with peripartum traits in dairy cows. VIII. Hormonal profiles associated with dystocia

Parental Behavior in Bovines

After approximately 9 months, cows give birth to one calf. They usually try to separate from the herd if kept outdoors, but this depends on the possibilities to hide. When the calf is born, the cow immediately stands up and starts licking the calf, and this is most intense for the first hour. During this time, the cow is very protective of her calf and may attack anyone trying to come close to it, especially if the cow is not so used to human handling. The calf tries to stand up and falls in the beginning, but it usually stands about half an hour later. Once standing, the calf searches for the udder, and after approximately 2 h, the calf is suckling the colostrum from the cow's teats. The calf is born without an immune defense, and it, therefore, needs to suckle enough colostrum from the cow to get protection against infections. If the calf does not succeed in suckling within 4-6 h after birth, the farmer must milk the cow and give the calf at least 2-4 l of colostrum in a teat bottle. If the farmer has frozen colostrum of good quality in the freezer, and it is either difficult to milk the cow or her colostrum is of too low quality, the frozen colostrum can be warmed up and given to the calf. Beef calves are usually allowed to stay with their mother until they are 6-8 months old, when they are separated from the cow and then weaned. Dairy calves are usually separated from their mother immediately or within a few days after birth and raised by artificial milk feeding. In the beginning or during the whole milk period (6-12 weeks), they may be kept individually indoors in crates or outdoors in hutches. After weaning, they are usually group housed.

Vaginal temperature before calving assessed with wireless vaginal temperature sensor in dairy and beef cattle

We evaluated the daily and hourly vaginal temperature changes and the relationships between the dams' breed and parity by using a commercially available vaginal temperature sensor in 72 Holstein (Hol) calvings and 101 Japanese Black (JB) calvings. Vaginal temperature sensors inserted 7-10 days before the expected calving day sounded two alerts: when the temperature fell below the threshold (Alert 1), and when the sensor reached the ambient temperature after falling out of the dam's vagina with the rupture of the allantoic sac (Alert 2). The durations from Alert 1 to Alert 2 (Time 1) and from Alert 2 to delivery (Time 2) were calculated. Only Time 1 in the Hol group tended to be affected by parity and parity × calf body weight. In the JB group, none of the factors examined affected Time 1 or Time 2. The alert detection rates did not differ by parity in either breed or by the temperature threshold in Hol. However, the Hol group's alert detection rate was significantly lower than the JB group's (p < 0.05). The daily average temperature was higher in the Hol group and the primiparous dams than those in the JB and multiparous dams; it increased slightly from Day -7 to -3 (Day 0 = the day of calving) and then dropped dramatically on Days -1 and 0. The hourly vaginal temperature difference from -48 h of calving showed a typical pattern, i.e., a decrease from -30 h of Alert 1 and an increase at -6 h of Alert 1. The decrease and increase might be the regression of the pregnant corpus luteum and the beginning of the contractions, respectively. The temperature differences were significantly affected by parity and calving ease (p < 0.01). The primiparous dams showed wider temperature differences compared to the multiparous dams in both breeds (p < 0.001). No typical temperature difference pattern was observed in assisted calving or dystocia. The alert detection rate, the Time durations, and the vaginal temperature differences were affected by the dams' breed and parity. However, measuring vaginal temperatures proved useful for predicting the calving regardless of the breed and parity. The effect of calving ease remains unclear due to the low number of assisted calvings herein.

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.

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.

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

Plasma concentrations of progesterone, oestradiol-17beta, oestrone, oestrone sulphate and PGFM have been measured daily during the first peri-partum period of 45 Hereford x Friesian heifers bred at 11 months of age. Anatomical measurements of dam and calf were also recorded. Twelve of the calvings were scored easy, 33 difficult. Each of five models (fitted by linear logistic regression) relating difficulty of calving to the hormonal and anatomical measurements, predicts with at least 94% accuracy the calving score (easy or difficult) among the calvings. The models predict that increases of progesterone concentration on the day before calving, of oestrone sulphate concentration on the day after calving and of heifer heart girth decrease the odds of difficult calving, whereas increases of heifer body length and of calf head circumference increase the odds of difficult calving.

Dystocia-related risk factors

Dystocia is one of the leading causes of calf mortality between birth and weaning in beef cattle. An understanding of the effects of parturition and dystocia on perinatal calf viability is paramount for the development of breeding and calving programs that will minimize calf losses. This article discusses the factors affecting birth weight and replacement heifer development and redefines dystocia as any birth that reduces calf viability, causes maternal injury, or reduces maternal reproduction.

Factors associated with edema of the mammary gland in primigravid dairy heifers

The severity and anatomical extent of mammary edema (edema) of 73 primigravid Holstein heifers was scored, and certain hormones in peripheral blood plasma were quantified. The objective was to obtain by least-squares analysis of covariance independent estimates of the association of each hormone and other factors with edema scores around first calving. Mammary edema prepartum increased with age of heifer and gestation length, decreased as calf birthweight increased, but was unrelated to seasonal fluctuations in temperature and photoperiod. The increase in edema during the last week of pregnancy was accounted for by associations with prepartum concentrations of hormones in plasma. The independent estimates of hormonal relationships to edema score prepartum were positive for plasma estrone and estradiol-17 alpha and were negative for plasma estradiol-17 beta and progesterone. Plasma prolactin was not related to edema score. After parturition, estradiol-17 beta was the only independent variable associated (negatively) with edema. The results indicate a complicated interaction among the sex steroids of late pregnancy wherein some steroids may promote edema and other steroids may inhibit edema in heifers.