Effect of Comprehensive Educational Training to Calving Personnel on the
Incidence of Stillbirth in Holstein Dairy Cows
Visiting Scholar:
Sascha Idema
Veterinary Student
University of Utrecht
Supervisors:
Dr. Gustavo M. Schuenemann
Department of Veterinary Preventive Medicine, College of Veterinary Medicine,
The Ohio State University
Dr. P.L.A.M Vos
Department Farm Animal Health, Faculty Veterinary Medicine,
University of Utrecht
1
Abstract
The objectives of the present observational study were 1) to assess the time from the
appearance of AS or feet to birth (and calving progress) for Holstein cows (primiparous [PRIM]
and multiparous [MULT] with assisted and unassisted births and 2) to assess the effect of
educational training to dairy personnel on stillbirth. A total of 385 Holstein dairy cows were
enrolled in this observational field study. The time from AS appearance to birth (minutes), from
feet appearance outside the vulva to birth (minutes), and calf birth weights (kg) in PRIM and
MULT cows were analyzed using proc MIXED of SAS. The incidence of stillbirths (born dead
or died within 24 hours after birth) and clinical metritis were analyzed using proc GLIMMIX of
SAS. Time from AS or feet appearance, cow behavior during labor stage, calving progress (signs
of imminent births), and stillbirth were recorded from unassisted or assisted cows. For eutocic
births, labor was characterized for transitioning from standing to lying position. For dystocic
births, labor was characterized a restless behavior such as frequent transitioning between
standing and lying positions. The time from amniotic sac (AS) or feet appearance to birth was
54.2 or 48.8 minutes, respectively. Although not statistically significant, the proportion of
stillbirth in cows assisted by trained calving personnel was lower (4.7%) compared to cows
assisted by personnel without training (7%). Recognizing the signs of calving progress and
imminent birth is critical to determine the appropriate time for obstetric intervention and for
positive outcomes (calf and dam). Comprehensive educational training to dairy personnel should
be a top priority to reduce the negative effects of dystocia on calves and dams.
2
Introduction
Maximizing reproductive performance of dairy herds is critical to ensure optimum yearly
milk yield. Several risk factors at the time of calving (e.g., dystocic births, stillbirth),
hypocalcemia, and early post-partum uterine diseases (retained fetal membranes, metritis, and
clinical endometritis) affect reproductive performance of dairy cows. It is well documented that
cows with dystocic births are prone to develop uterine disease; thereby, reducing reproductive
efficiency (e.g., increased calving interval) and decreasing milk yield and profit. Research has
shown that careful monitoring of the calving process and timely obstetric intervention reduced
the incidence of stillbirth under field conditions (Schuenemann et al., 2011). Therefore,
comprehensive calving training to dairy personnel should be a top priority to minimize the
negative effects of dystocia on stillbirth and cow uterine health.
a. Physiology of parturition
Parturition is initiated by production of fetal corticoids and removal of the progesterone
block. During gestation high progesterone concentration inhibits the myometrium contractility
and tone. Initially, progesterone is produced by the corpus luteum (CL) to support pregnancy.
After 6-8 months of gestation, the placenta produces progesterone in order to maintain gestation.
At the end of gestation, the fetus anterior pituitary releases adrenal corticotropin hormone
(ACTH), which stimulates the fetal adrenal cortex to produce corticoids. Elevation of fetal
corticoids causes a cascade of endocrine reactions in the dam, resulting in removal of the
progesterone block and enabling myometrial contractions. Removal of the progesterone block to
myometrial activity occurs because fetal cortisol promotes the synthesis of three enzymes that
convert progesterone to estradiol. The conversion of progesterone to estradiol causes a drop in
progesterone and an elevation of estradiol. Estradiol initiates secretory activity of the
reproductive tract, and the mucus secretions lubricate the birth canal prior to birth. The peak of
estrogen signals the early pre-parturient period. Besides initiating the conversion pathway of
progesterone to estradiol, fetal corticoids also cause the placenta to synthesize PGF2α, which
3
helps to remove the progesterone block and thereby increasing myometrial activity. Also, PGF2α
causes regression of the CL, reducing circulating progesterone and leading to parturition.
Another important hormone involved in successful parturition is relaxin. Relaxin is a
glycoprotein that is produced by the corpus luteum. The synthesis of relaxin is stimulated by
PGF2α. Relaxin causes a softening of the connective tissue in the cervix and promotes elasticity
of the pelvic ligaments in order to prepare the birth canal by loosening the supportive tissues so
that passage of the fetus can occur with relative ease. Also, relaxin allows oxytocin driven
myometrial contractions occur, leading to expulsion of the fetus (Noakes et al., 2009).
b. Signs of imminent calving
Parturition is a natural process consisting of three stages and each stage progresses gradually
from one stage to the next. Enlargement of the udder, relaxation of the pelvic ligaments (i.e.,
swelling of the vulva), and discharge of vaginal fluids are common signs of imminent births in
primiparous and multiparous cows. Eutocia is defined as a normal birth without assistance,
whereas dystocia has been defined as a difficult birth resulting in prolonged calving or severe
assisted extraction of the calf at birth. Assisted calving has been defined as a birth in which
assistance is required (e.g., correction of malposition), but this may not necessarily result in
dystocia. The amount of assistance that is provided during parturition determines the degree of
dystocia (Mee, 2004). Prolonged parturition can result in serious complications to both the fetus
and the dam. Stage 1 is characterized by initiation of myometrial contractions by removing of the
progesterone block and cervical dilation (i.e., ligaments and joint of the pelvic bone) and it ends
with a fully dilated cervix. The increased levels of estradiol and PGF2α result in increased
myometrial contractions, starting to push the fetus toward the cervix, applying pressure to the
cervix. As the fetus progress through the birth canal, stimulating terminal sensory neurons of the
cervix and releasing oxytocine from the posterior pituitary. Oxytocine stimulates contraction of
the myometrium, forcing the fetus to progress through the cervix, which again increases the
oxytocine secretion and more uterine contractions. The first stage of parturition causes dilation of
the cervix and entry of the fetus into the birth canal. Stage 1 last for about 2 to 6 hours and
although variation in behavioral signs exist between cows and first-calving heifers, stage 1 is
characterized by olfactory ground checks, nest-building-like behavior, licking their own bodies
4
(e.g., hind back and limbs), vocalization, discharge of feces, restlessness (i.e., walking, standing
up, and lying down), and tail raising (Wehrend et al., 2006; Miedema et al., 2011). Some of these
behavioral signs such as tail raising, restlessness, and vocalization extend into stage 2 of labor.
Stage 2 is characterized by the appearance of the amionitc sac (AS) outside the vulva and the
expulsion of the fetus by strong myometrial and abdominal contractions and takes 30 to 60
minutes. The sign of the onset of the second stage is the appearance of abdominal contractions
and cows usually lie down as the calf enters the birth canal. As myometrial contraction continue
to increase, the feet and head of the fetus put pressure on the fetal membranes. Rupture of the
fetal membranes and subsequent loss of amniotic and allantoic fluid lubricates the birth canal. As
the fetus enters the birth canal, it becomes hypoxic which promotes fetal movement that in turn
promotes further myometrial contractions. The uterine contractions are accompanied by
abdominal muscle contractions that further aid in expulsion of the fetus (Senger 2003). Cow
behavior, as a qualitative judgment, can be used to recognise when cows may be about to calve.
Behaviors such as eating, ruminating and grooming decrease in duration over a number of days
before calving. At the time of calving restlessness is characterized by an increase in the number
of transitions between standing and lying and also by an increase in time spent walking.
Miedema et al. (2011) found that cows increased the number of lying bouts and frequency of tail
raises during the final 6 hours prior to birth in unassisted cows. During the expulsion phase,
multiparous cows are characterized by lying down at the onset of the abdominal contractions and
remaining recumbent until birth. The AS appears about 10 min after the first abdominal
contractions and calving progress is every 15 min and a set of intense abdominal contractions
complete the birth (Schuenemann et al. 2011).Important differences exist between primiparous
and multiparous cows in their pre-calving behavior. Primiparous dairy cows usually give birth at
around 2 years of age. Primiparous cows are more restless, characterized by increased frequency
of lying-standing positions at the beginning of labor stage and the second stage of parturition is
longer. Extended duration of parturition is often associated with calving difficulties. Proudfoot et
al. (2009) found that cows with dystocia had more standing bouts and spent less time eating
during the 18 hours before calving. Also more cows with dystocia were found to rub against
walls, discharge urine and scrape the floor (Wehrend et al. 2006).
Stage 3 is characterized by fetal membrane expulsion. Generally, it takes about 6 to 12 hours
after calf delivery and requires dislodging of the chorionic villi from the crypts of the maternal
5
side of the placenta. This release is caused by powerful vasoconstriction of arteries in the villi.
Vasoconstriction reduces pressure and thus allows the villi to be released from the crypts.
Monitoring of dairy cows around the time of calving is critical to identify cows in need of
calving assistance and to minimize the effects of dystocia (e.g., stillbirth, uterine diseases).
c. Risk factors for dystocia
Difficulties in parturition usually occur in the second stage (expulsion of the fetus). Causes of
dystocia (difficult birth) are an excessive size of the fetus, failure of proper fetal rotation, uterine
torsion, and twins (Senger 2003). Fetal size is controlled by both the dam and the sire. Therefore,
primiparous dams are at greater risk that fetal size will exceed the ability of the female to give
birth successfully. Feto-pelvic incompatibility may be the most important factor for early calf
mortality in heifers and has a less pronounced effect in older cows (Berger et al., 1992).
Normally, as the pressure inside the uterus continues to increase, the fetus rotates so that the
front feet and head are positioned to the posterior of the dam to insure a proper delivery. The
fetus is usually delivered in anterior presentation, dorsal position and extended posture, although
a small proportion of normal deliveries may occur in posterior presentation, dorsal position and
extended posture (Noakes et al. 2009). Failure of proper fetal rotation leading to an abnormal
position of the fetus results in difficult births and sometimes impossible presentations that
require caesarean section (Senger 2003). Abnormal fetal position is most influenced by the
number of fetuses, parity,sire, and breed (Mee, 2008). Uterine torsion has been associated with
increased calf size or reduced rumen volume before parturition, which result in increased
abdominal space for the gravid uterus to rotate (Laven et al., 2005). The intermediate risk factors
for uterine torsion are excessive fetal movement during stage 1 of calving as the fetus adopts the
birth posture, increased uterine instability at term and possibly a deeper abdomen in some dairy
breeds (Mee, 2008). Twins generally cause dystocia because both twins may be presented
simultaneously or the first fetus is positioned abnormally and therefore blocks the second fetus or
the uterus becomes fatigued due to increased time in labor (uterine and abdominal contractions).
When compared with other types of dystocia, multiparous cows are at greater risk for uterine
torsion than primiparous cows, while animals suffering from fetopelvic disproportion or carrying
twins are at a lesser risk (Aubry et al., 2008). Additionally, dystocia has several environmental
6
and genetic causes such as age and parity of the dam, sex of the calf, season of calving and
nutritional level of the periparturient cows during gestation. Calf birth weight may be the most
common cause of stillbirth associated with dystocia. The incidence of calf mortality, even up to 1
month after birth, is much higher when parturition has been difficult. Berger et al. (1992) showed
that perinatal mortality was generally lowest at intermediate calf birth weights of 26 to 35 kg and
highest at calf birth weights above 35 kg. However Linden et al. (2009) found that neither calf
birth weight, nor the cow calf index (calf weight/cow height at parturition) were associated with
stillbirth incidence, calf mortality past 12 hours of life, cow reproduction or cow survival.
Additionally, calf birth weight, and especially the ratio of calf birth weight to dam size, can be
associated with some downstream health effects such as obstetrical assistance, lameness events
and milk production (Linden et al., 2009).
d. Risk factors for uterine diseases
Immediately after parturition, the dam enters a period of reproductive repair called the
puerperium. Parturition occurs in a non-sterile environment and bacterial contamination from the
vagina enters into the uterus. Under normal conditions, expulsion of lochia and debris are
expected during the process of uterine involution and postpartum cows will resume cyclicity
shortly after parturition. However, several risk factors such as delivery of twins, retained fetal
membranes, and dystocic births prone postpartum cows to uterine diseases (e.g., metritis; Dubuc
et al., 2011). Risk factors for metritis include increased nonesterified fatty acid prepartum
(NEFA ≥0,6 mmol/L, associated with negative energy balance in early postpartum), dystocia,
delivery of twins, retained placenta, stillbirth, abortion, prolaps uterus and increased haptoglobin
in serum in the first week postpartum (≥0,8 G/l). Risk factors for purulent vaginal discharge
include twins, dystocia, metritis, retained placenta and increased Hapto in the first week
postpartum (≥0,8 G/l, caused by increased inflammation from the uterus in the early postpartum
period, which maintains endometrial, cervical or vaginal inflammation). Risk factors for
cytological endometritis include low body condition score at parturition (≤2.75), parity, season,
hyperketonemia (≥1,100 µmol/L) and increased Hapto in the first week postpartum (≥0,8 G/l).
Energy balance indicators (as increased NEFA, reduced feed intake prepartum and increased
7
BHBA early postpartum) and metabolic disorders (as abomasal displacement, hypocalcemia and
ketosis) have been associated with an increased risk of cytological endometritis.
Dairy cows experiencing difficult births (dystocia) are prone to develop uterine diseases.
Therefore, focusing on proactive management of dystocia should be a top priority to control
metritis. Being able to recognize the signs of imminent birth and determine the appropriate time
for obstetric intervention are critical to minimize the negative effects of dystocia (e.g., stillbirth).
The objectives of the present observational study were 1) to assess the time from the appearance
of AS or feet to birth (and calving progress) for Holstein cows (primiparous [PRIM] and
multiparous [MULT] with assisted and unassisted births and 2) to assess the effect of educational
training to dairy personnel on stillbirth.
Materials and Methods
a. Animal and Facilities
A total of 385 Holstein cows from 2 commercial dairy operations were used in this
observational study. Periparturient Holstein dairy cows were housed in free-stall barns bedded
with sand. Cows were fed twice daily, in the morning and afternoon, with a TMR formulated to
meet or exceed dietary nutritional requirements for dry dairy cows (NRC, 2001). Pregnant cows
were located in the prepartum pen, which was located right next to the maternity pen. Cows at
labor were placed in an individual maternity pen (approximately 20 m2) padded with wheat
straw bedding and constantly monitored until birth. This study was conducted in August and
September, 2011.
b. Assessment of Calving Signs and Progress for Assisted and Unassisted Births
A subset of Holstein cows (n=29) were used to assess the time from AS appearance to
birth, timing from feet appearance to birth, calving progress, and stillbirths (born dead or died
within 24 h after birth) between assisted and unassisted births (Figure 1). Slight protrusion of
the AS outside of the vulva was defined as the onset of AS appearance. Approximately every 0.5
hour, calving personnel walked through the prepartum pen looking for cows with signs of
8
imminent calving (presence of mucus-blood around the perineum or at the onset of AS
appearance outside the vulva). Cows showing signs of imminent calving were immediately
moved to an individual maternity pen and constantly monitored until birth by one person
positioned outside of the maternity pen. Any cows with advanced AS appearance (hanging
outside of the vulva) or showing feet did not meet the criteria and were not enrolled in the study.
Immediately following calving, cows were moved to the fresh pen.
c. Educational Training to Dairy Personnel and Stillbirth
The effect of calving training to dairy personnel on stillbirths was assessed (Figure 1).
Prior to the start of this observational study, a comprehensive calving management training that
included the signs of calving, dystocia management, frequency of observations, and hygiene
practices) was provided to calving personnel. As part of the training, calving personnel provided
assistance to cows without calving progress at approximately 70 min after the onset of AS
appearance (Schuenemann et al., 2011) or earlier if only one foot had been exteriorized outside
the vulva. The calving ease (CE) of cows (assistance provided at birth) was recorded using a 1-4
scale (1 = no assistance provided; 2 = light assistance by one person without the use of
mechanical traction; 3 = mechanical extraction of the calf with an obstetric calf-puller; and 4 =
severe dystocia, surgery or fetotomy needed). Additionally the proportion of stillbirths (born
dead or died within 24 h after birth) was recorded. Calf birth weights were recorded using a
mechanical hanging scale (Pelouze® Rubbermaid, Winchester, VA) immediately after birth. All
cows had their body condition scores (BCS; scale 1-5; Ferguson et al., 1994) recorded
immediately after calving.
d. Statistical Analysis
The time from AS appearance to birth (minutes), from feet appearance outside the vulva
to birth (minutes), and calf birth weights (kg) in PRIM and MULT cows were analyzed using
proc MIXED of SAS (SAS, 2009). The incidence of stillbirths (born dead or died within 24 h
after birth) and clinical metritis were analyzed using proc GLIMMIX of SAS (SAS, 2009). The
times from AS or feet of the calf appearance to birth were reported as least square means (LSM
9
SEM), mean ± 2 SD (Wenz et al., 2011), and Upper-Lower 95% CI (Smit et al., 2003) for
unassisted (eutocia) and assisted births (dystocia). Differences in individual least squares means
were adjusted by using Tukey-Kramer method. A P < 0.05 was considered statistically
significant.
10
Results
Periparturient Holstein cows (n=385) were exposed to calving personnel that received
training or no training. In a subset of cows (n=29), calving signs (i.e., cow behavior), and calving
progress were recorded. The proportion of stillbirths, retained fetal membranes (RFM), hygiene
scores of the perineum and BCS were recorded
a. Assessment of Calving Signs for Assisted and Unassisted Births
The distribution of 29 Holstein dairy cows (assisted or unassisted births) with respect to
parity (primiparous or multiparous), BCS at calving, sex of the calf (%), retained fetal
membranes (%), and mean time to expel fetal membranes after births, is provided in Table 1.
Cows unassisted at birth had a mean parity of 1.5 and cows assisted at birth a mean parity of 1.9.
The mean BCS immediately after birth was 3.4 for both groups of cows. In the unassisted group
the amount of female and male calfs was similar (50%), the assisted group contained 31.5%
female calfs and 61.5% male calfs . None of the unassisted cows retained their fetal membranes
(failure to expel fetal membranes within 24 hours), whereas 23% of the assisted cows had
retained fetal membranes. The mean time to expel fetal membranes was 15.2 hours for the
unassisted group versus 14.6 hours for the assisted group (Table 1).
The estimated calf body weight at birth (kg), the proportion of stillbirth (%) and time
(min) from amniotic sac (AS) or feet of the calf appearance to birth was assessed during the
labor stage of 29 Holstein dairy cows with assisted (n=12) and unassisted births (n=17) (Table
2). The proportion of stillborn calf was 25% for the assisted births, whereas unassisted cows
showed no stillbirth. A significant interaction was found between duration of stage 2 of
parturition and assistance. The mean time from AS appearance to birth in minutes was 42.8 ±
11.4 for unassisted cows, whereas for assisted cows 89.7 ± 45. The mean time from feet
appearance to birth was 29.2 ± 19.6 for unassisted cows compared to 61.7 ± 50 for assisted cows.
Calf birth weight was higher in the assisted group than in the unassisted group (41.0 kg versus
38.2kg, respectively (Table 2).
11
Periparturient cows were placed in an individual maternity pen and constantly monitored
until birth. Cow behavior (lying down or standing up), frequency and duration (seconds) of
abdominal contractions and calving progress were recorded during the labor stage of an
unassisted birth (eutocia) from a primiparous Holstein dairy cow (figure 2) and a multiparous
Holstein dairy cow (figure 3) and an assisted birth (dystocia)from a multiparous Holstein dairy
cow (figure 4).
Frequency and duration (seconds) of abdominal contractions during the labor stage of
unassisted birth (eutocia) from a primiparous Holstein dairy cow shows a more varying graph
compared to a multiparous cow. Frequency and duration (seconds) of abdominal contractions
increases gradually in multiparous cows until birth, whereas primiparous cows show an
alternating pattern in frequency of abdominal contractions. During the first part of the labor stage
of an assisted birth (dystocia) from a multiparous Holstein dairy cow, the frequency and duration
of abdominal contractions increase gradually like eutocia in a multiparous cow, but after 45
minutes an irregular pattern like in primiparous cows was recorded and eventually abdominal
contractions were omitted, making intervention necessary.
Primiparous cows and multiparous cows with dystocia show an increase in the number of
transitions between standing and lying, possibly indicating restlessness, whereas multiparous
cows with an unassisted birth (eutocia) showed less transitions between standing and lying and
more laying bouts.
Calving progress in eutocic primiparous cows is comparable with multiparous cows.
Amniotic sac appearance and showing feet is within 10-15minutes and showing nose, head and
birth is another 30 minutes later. Stage 2 takes a little longer in primiparous cows (birth after 51
min.) compared to multiparous cows (birth after 42 min.). However, the multiparous dystocic
cow showed amniotic sac appearance at 6 min. and feet just after 21 min, but after 71 min.
intervention was required due to lack of birth progress. Intervention involves pulling the calf out
by hand, usually with the aid of ropes/chains wrapped around the calf’s fore feet, or using a
calving jack in more serious cases.
12
b. Educational Training to Dairy Personnel and Stillbirth
The effect of educational training on stillbirths was assessed on 385 periparturient Holstein
dairy cows under field conditions. The proportion of stillbirth was assessed in cows (n=216) that
were assisted by trained calving personnel or cows (n=169) assisted by dairy personnel without
training. Dairy personnel that received training resulted in fewer stillbirths (4.7±2%) compared
to non-training personnel (7±2%; Figure 1).
DISCUSSION
The primary findings of the present observational study were 1) the time from AS or feet
appearance to birth was 54.2 or 48.8 minutes, respectively, 2) calving progress was evident every
15-20 minutes during the labor stage, and 3) although non-significant dairy personnel reduced
the proportion of stillbirth by 2.3 percentage points (from 7% to 4.7%) after receiving a
comprehensive calving management training. These findings have important implications for
calving dairy personnel under field conditions.
A recent study showed that the estimated reference times from AS appearance to birth
were 69.7 min and from feet appearance to birth were 64.6 min for eutocic births (Schuenemann
et al., 2011). Cows with dystocic births have a longer time from AS or feet appearance to birth
and increased incidence of stillbirth compared with cows with eutocic calvings. Therefore, it is
important that calving personnel assess the time that a cow is in labor to determine whether
intervention is required. The observation of calving signs as AS or feet appearance outside the
vulva can be used as reference times for obstetric intervention in Holstein cows that need
assistance during difficult births (dystocia).
Calving progress (AS appearance, showing feet, nose, head, shoulder of the calf outside
the vulva until birth) is evident every 15 min for eutocic births (Schuenemann et al., 2011). It is
important to note when a malposition (e.g., appearance of one leg outside the vulva) is evident
immediately after AS appearance, early obstetric intervention is required to correct the
malposition. For uterine torsion, where calving personnel are unable to assess the appearance of
13
AS or showing feet outside the vulva, appropriate obstetric knowledge is important to determine
the time for intervention.
The time spent in labor combined with the time from the appearance of the AS or feet to
birth, and the assessment of calving progress should be used as guidelines for obstetric
intervention during difficult births. Calving personnel should start assisting cows 70 min after
AS appearance or 65 min after feet appearance outside the vulva (Schuenemann et al. 2011).
These reference times should be interpreted in combination with appropriate obstetrical
knowledge and examination. Comprehensive calving management training should provide clear
guidelines on the signs of imminent birth, obstetric strategies (e.g. how to correct malpositions or
presentations), hygiene practices, frequency of observations, record keeping, and the appropriate
time for intervention, in order to reduce the incidence of stillbirth and reduce the negative effects
of dystocia on calves and dams.
CONCLUSIONS
Being able to recognize the signs of imminent birth and calving progress is critical to
determine the time of obstetric intervention under field conditions. The time from AS or feet
appearance outside the vulva to birth and the description of calving progress (for eutocic birth)
provide useful information to determine the appropriate time for obstetric intervention. Early
intervention has the potential to reduce the incidence of stillbirth, but also has the potential for
dam injury. Dairy personnel should use the information described for eutocic births to determine
the appropriate time for intervention. Future research should focus on predictors of dystocic
births as early warning signals to intervene in time if necessary.
Acknowledgements
The author thanks the collaborating dairy farms and their staff for providing the animals
used in this study. In addition, the authors gratefully acknowledge the University of Utrecht and
The Ohio State University for this internship opportunity and experience. Also appreciation is
extended to Santiago Bas for helping with data collection. I want to thank my advisor Dr.
Gustavo M. Schuenemann for his tremendous help and support in development of this project.
14
References
Aubry, P. L.D. Warnick, L.DesCôteaux, É. Bouchard. 2008. A study of 55 field cases of uterine
torsion in dairy cattle. Can.Vet J. 49:366–372.
Berger, P. J., A. C. Cubas, K. J. Koehler and M. H. Healey. 1992. Factors affecting dystocia
and early calf mortality in Angus cows and heifers. J. Anim. Sci. 70:1775-1786.
Correa, M. T., H. Erb, and J. Scarlett. 1993. Path analysis for seven postpartum disorders of
Holstein cows. J Dairy Sci 76:1305-1312.
Dematawewa C.M.B., and P. J. Berger. 1997. Effect of dystocia on yield, fertility, and cow
losses and an economic evaluation of dystocia scores for Holsteins. J Dairy Sci 80:754–761.
Doornbos, D.E., R.A. Bellows, P.J. Burfening, and B.W. Knapp. 1984. Effects of dam age,
prepartum nutrition and duration of labor on productivity and postpartum reproduction in
beef females. J. Anim. Sci. 59: 1-10.
Dubuc, J., T.F. Duffield, K.E. Leslie, J.S. Walton, and S.J. LeBlanc. 2010a. Definitions and
diagnosis of postpartum endometritis in dairy cows. J. Dairy Sci. 93:5225–5233.
Dubuc, J., T.F. Duffield, K.E. Leslie, J.S. Walton, and S.J. LeBlanc. 2010b. Risk factors for
postpartum uterine diseases in dairy cows. J. Dairy Sci. 93:5764–5771.
Dubuc, J., T.F. Duffield, K.E. Leslie, J.S. Walton, and S.J. LeBlanc. 2011a. Randomized clinical
trial of antibiotic and prostaglandin treatments for uterine health and reproductive
performance in dairy cows. J. Dairy Sci. 94:1325–1338.
Dubuc, J., T.F. Duffield, K. E. Leslie, J. S. Walton, and S. J. LeBlanc. 2011b. Effects of
postpartum uterine diseases on milk production and culling in dairy cows. J. Dairy Sci.
94:1339–1346.
15
Ferguson, J.D., D.T. Galligan, and N. Thomsen. 1994. Principal descriptors of body condition in
Holstein dairy cattle. J. Dairy Sci. 77:2695-2703.
Frazer, G.S., N.R.Perkins, and P.D.Constable. 1996. Bovine uterine torsion: 164 hospital referral
cases. Theriogenology 46:739-758.
Gaafar, H. M. A., Sh. M. Shamiah, M. A. Abu El-Hamd, A. A. Shitta & M. A. Tag El-Din.
2010. Dystocia in Friesian cows and its effects on postpartum reproductive performance and
milk production. Trop. Anim. Health Prod. 43:229–234.
Heringstad, B., Y. M. Chang, M. Svendsen, and D. Gianola. 2007. Genetic analysis of calving
difficulty and stillbirth in Norwegian Red Cows. J. Dairy Sci. 90:3500–3507.
Johanson, J. M., and P. J. Berger. 2003. Birth weight as a predictor of calving ease and perinatal
mortality in Holstein cattle. J. Dairy Sci. 86:3745–3755.
Laven, R., Howe, M. 2005. Uterine torsion in cattle in the UK. Veterinary Record 157:96
Linden, T. C., R. C. Bicalho, and D. V. Nydam. 2009. Calf birth weight and its association with
calf and cow survivability, disease incidence, reproductive performance, and milk
production. J. Dairy Sci. 92:2580–2588.
Lombard, J. E., F. B. Garry, S. M. Tomlinson, and L. P. Garber. 2007. Impacts of dystocia on
health and survival of dairy calves. J. Dairy Sci. 90:1751–1760.
Mangurkar, B. R., J. F. Hayes, and J. E. Moxley. 1984. Effects of calving ease-calf survival on
production and reproduction in Holsteins. J Dairy Sci 67:1496-1509.
Mee, John F. 2004. Managing the dairy cow at calving time. Vet Clin Food Anim 20: 521–546.
Mee, J.F. 2008. Prevalence and risk factors for dystocia in dairy cattle: A review. The Veterinary
Journal 176:93–101.
16
Miedema, Hanna M., M.S. Cockram, C. M. Dwyer, A.I. Macrae. 2011. Changes in the behaviour
of dairy cows during the 24 h before normal calving compared with behaviour during late
pregnancy. Appl. Anim. Behav. Sci. 131:8–14
Miedema, H.M., M.S. Cockram, C.M. Dwyer, A.I. Macrae. 2011. Behavioural predictors of the
start of normal and dystocic calving in dairy cows and heifers. Appl. Anim. Behav. Sci.
132:14–19.
Meijering, A. 1984. Dystocia and stillbirth in cattle – A review of causes, relations and
implications. Livest. Prod. Sci. 11: 143-177.
NRC. 2001, Nutrient Requirements of Dairy Cattle. 7th rev. ed. National Academy Press,
Washington, DC.
Proudfoot, K. L., J. M. Huzzey, and M. A. G. von Keyserlingk. 2009. The effect of dystocia on
the dry matter intake and behavior of Holstein cows. J. Dairy Sci. 92:4937–4944.
SAS Institute Inc. 2009. SAS/STAT 9.2 User’s Guide. 2nd ed. SAS Institute Inc., Cary, NC.
Schuenemann, G.M., S. Bas, E. Gordon, and J. Workman. 2011. Dairy calving management:
Assessment of a comprehensive program for dairy personnel. J. Dairy Sci. (Abstract; ADSA
2011).
Schuenemann GM, Nieto I, Bas S, Galvão KN, Workman J. 2011. Assessment of calving
progress and reference times for obstetric intervention during dystocia in Holstein dairy
cows. J Dairy Sci. 94: 5494-5501.
Sheldon, I. M., G.S. Lewis, S. LeBlanc, R. O. Gilbert. 2006. Defining postpartum uterine disease
in cattle. Theriogenology 65: 1516–1530.
17
Smit, W., P. van Dijk, M.J. Langedijk, N. Schouten, N. van den Berg, D.G. Struijk, and R.T.
Krediet. 2003. Peritoneal function and assessment of reference values using a 3.86% glucose
solution. Perit. Dial. Int. 23:440-449.
USDA/APHIS. 2009. Calving Intervention on U.S. Dairy Operations, 2007.
USDA/APHIS.2010. Dairy 2007 – Heifer Calf Health and Management Practices on U.S. Dairy
Operations, 2007.
De vries, A., J. D. Olson, and P. J. Pinedo. 2010. Reproductive risk factors for culling and
productive life in large dairy herds in the eastern United States between 2001 and 2006. J.
Dairy Sci. 93:613–623.
Wehrend, A., Hofmann, E., Failing, K., Bostedt, H., 2006. Behaviour during the first stage of
labour in cattle: influence of parity and dystocia. Appl. Anim. Behav. Sci. 100:164–170.
Wenz, J.R., D.A. Moore, and R. Kasimanickam. 2011. Factors associated with the rectal
temperature of Holstein dairy cows during the first 10 days in milk. J. Dairy Sci. 94:18641872.
18
List of Tables:
Table 1. Distribution of 29 Holstein dairy cows (assisted or unassisted births) with respect to
parity (primiparous or multiparous), BCS at calving, sex of the calf (%), retained fetal
membranes (%), and mean time to expel fetal membranes after births…………………………….
Table 2. Estimated calf body weight at birth (kg), stillbirths (%), and time (min) from amniotic
sac (AS) or from feet of the calf appearance to birth during the labor stage of Holstein cows with
unassisted (n = 17) or assisted births (n = 12)……………………………………………………...
19
Table 1. Distribution of 29 Holstein dairy cows (assisted or unassisted births) with respect to
parity (primiparous or multiparous), BCS at calving, sex of the calf (%), retained fetal
membranes (%), and mean time to expel fetal membranes after births.
Unassisted Birth
Assisted Births
(n=17)
(n=12)
Parameters
Calving ease scores at birth
17
1 = no assistance provided
2 = light assistance
7
3 = mechanical extraction
5
4 = severe dystocia
0
Parity (n)
1.5
1.9
3.40
3.44
Female
50
31.5
Male
50
61.5
Retained fetal membranes (%)
0
23
15.2
14.6
Mean BCS of cows immediately after
birth
Sex of calf (%)
Mean time to expel fetal membranes (h)
1
Periparturient dairy cows (n = 29) were placed in an individual maternity pen and constantly
monitored for signs of calving during unassisted (eutocia) and assisted births (dystocia).
2
Assistance was provided to cows without calving progress approximately 70 min after the AS
appearance. The amount of assistance (1 = no assistance provided; 2 = light assistance by one
person without the use of mechanical traction; 3 = mechanical extraction of the calf with an
obstetric calf-puller; and 4 = severe dystocia, surgery or fetotomy needed) were recorded at birth.
20
Table 2. Estimated calf body weight at birth (kg), stillbirths (%), and time (min) from amniotic
sac (AS) or from feet of the calf appearance to birth during the labor stage of Holstein cows with
unassisted (n = 17) or assisted births (n = 12)
Unassisted Birth
Assisted Births
(n=17)
(n=12)
P-value
38.2
41.0
0.2
0
25
0.11
LSM ± SEM
42.7 ± 13b
89.1 ± 15a
0.03
Mean ± 2SD
42.8 ± 11.4
89.7 ± 45
95% CI (Lower-Upper)
17.4 – 68.2
55.6 - 122.5
LSM ± SEM
30.3 ± 12
61.7 ± 11
Mean ± 2SD
29.2 ± 19.6
61.7 ± 50
95% CI (Lower-Upper)
3.7 – 56.7
37.6 – 85.7
Parameters
Calf birth weight (Kg)1
Stillbirth (%)2
Time from AS appearance to birth (min)3
Time from feet appearance to birth (min)3
a,b
1
0.08
Values with different superscript letters within a row differ significantly at P < 0.05.
Calf body weight (kg) was recorded immediately after birth. Least square means (±SEM) were
estimated for unassisted and assisted births.
2
The proportion of stillborn calf (%) was recorded for unassisted and assisted births. Stillbirth
was defined as a calf born dead or died within 24 h after birth.
3
Periparturient dairy cows were placed in an individual maternity pen and the time period (min)
from the AS appearance to birth as well as from the feet of the calf appearance outside the vulva
to birth were recorded. Least square means (±SEM), mean (± 2 SD), and 95% CI were estimated
for unassisted and assisted births.
21
List of Figures
Figure 1. Scheme of the observational study ……………………………………………………23
Figure 2. Description of frequency and duration (seconds) of abdominal contractions during the
labor stage of unassisted birth (eutocia) from a primiparous Holstein dairy cow……………….24
Figure 3. Description of frequency and duration (seconds) of abdominal contractions during the
labor stage of unassisted birth (eutocia) from a multiparous Holstein dairy cow………………25
Figure 4. Description of frequency and duration (seconds) of abdominal contractions during the
labor stage of assisted birth (dystocia) from a multiparous Holstein dairy cow…………………26
Figure 5. Effect of calving management training to dairy personnel on the proportion of
stillbirths…………………………………………………………………………………………27
22
Figure 1. Scheme of the observational field study1.
Calving signs-progress,
and cow behavior
Dry-Off
Calving training
-60 DIM
Stillbirth
-1
Continue Project
0
Observational Study
1
Periparturint Hosltein cows (n=385) were exposed to calving personnel with or without training.
In a subset of cows (n=29), calving signs (i.e., cow behavior), calving progress, and stillbirth
were recorded.
23
Figure 2. Description of frequency and duration (seconds) of abdominal contractions during the
labor stage of unassisted birth (eutocia) from a primiparous Holstein dairy cow.1
LD
SU/LD
SU/LD
SN
SH Birth
1.2
SF
SU
Frequency of Contractions (#)
Frequency
Duration
AS
LD
1
20
0.8
15
0.6
10
0.4
5
0.2
0
Duration of Contractions (seconds)
25
0
3
6
9
12
15
18
21
24
27
30
33
36
39
42
45
48
51
Observational Period (minutes)
1
Periparturient primiparous cows were placed in an individual maternity pen and constantly
monitored until birth. Cow behavior (lying down or standing up), signs and progress of imminent
birth (amniotic sac appearance, showing feet, head, shoulder, and birth), and the onset of
frequency and duration of abdominal contractions were recorded during the labor stage of an
unassisted birth (eutocia; 30 kg male calf). The following signs of calving progress over time
were recorded: LD = Lying down; AS = Amniotic sac appearance; SF = Showing feet; SN =
Showing nose; and Birth = Births.
24
Figure 3. Description of frequency and duration (seconds) of abdominal contractions during the
labor stage of unassisted birth (eutocia) from a multiparous Holstein dairy cow.
SF
SN SH Birth
Frequency
AS
Duration
1.2
Frequency of Contractions (#)
16
1
14
12
0.8
SU/LD
10
0.6
8
6
0.4
4
0.2
2
0
Duration of Contractions (seconds)
LD
18
0
3
6
9
12
15
18
21
24
27
30
33
36
39
42
Observational Period (minutes)
1
Periparturient multiparous cows were placed in an individual maternity pen and constantly
monitored until birth. Cow behavior (lying down or standing up), signs and progress of imminent
birth (amniotic sac appearance, showing feet, head, shoulder, and birth), and the onset of
frequency and duration of abdominal contractions were recorded during the labor stage of an
unassisted birth (eutocia; 40 kg male calf). The following signs of calving progress over time
were recorded: LD = Lying down; AS = Amniotic sac appearance; SF = Showing feet; SN =
Showing nose; and Birth = Births.
25
Figure 4. Description of frequency and duration (seconds) of abdominal contractions during the
labor stage of assisted birth (dystocia) from a multiparous Holstein dairy cow.
LD
AS
SF
SU
SU/LD
Frequency
Duration
INT
1.2
LD
18
Frequency of Contractions (#)
SU/LD
SU/LD
1
16
SU
14
0.8
LD
12
10
0.6
8
0.4
6
4
0.2
2
0
Duration of Contractions (seconds)
20
0
3
6
9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69 71
Observational Period (minutes)
1
Periparturient multiparous cows were placed in an individual maternity pen and constantly
monitored until birth. Cow behavior (lying down or standing up), signs and progress of imminent
birth (amniotic sac appearance, showing feet, head, shoulder, and birth), and the onset of
frequency and duration of abdominal contractions were recorded during the labor stage of an
assisted birth (dystocia; 43 kg female calf). The following signs of calving progress over time
were recorded: LD = Lying down; AS = Amniotic sac appearance; SF = Showing feet; SN =
Showing nose; and INT = Intervention required due to lack of birth progress.
26
Figure 5. Effect of calving management training to dairy personnel on the proportion of
stillbirths.
7
Stillbirth (%)
6
5
4
3
2
(n=169)
(n=216)
Pre-Training
Post-Training
1
0
Calving Training to Dairy Personnel
A total of 385 Holstein dairy cows were enrolled in this field study. The proportion of stillbirths
in post-training cows (4.7±2%) was lower compared to pre-training cows (7±2%; P=0.3).
27