Risk Factors and Economic Impact of Dystocia in Dairy Cows: A Systematic Review

Abstract

Reproductive health problems are one of the most important problems that affect the production and productivity of dairy cows. Dystocia is also one of the reproductive health problems that cause considerable economic loss to the dairy industry. The main aims of this manuscript were to review risk factors and economic impact of dystocia in dairy cows. Dystocia is also defined as prolonged or difficult parturition and it is a condition in which the first or, especially the second stage of parturition was markedly prolonged for more than 6 hr and the cow required assistance. There are different causes and risk factors associated with dystocia in dairy cattle which can result from both maternal and foetal factors. Breed parity, weight and condition of cow at calving, sex and birth weight of calf, malpresentation, multiple calving can be a risk factors for dystocia. Foeto-pelvic incompatibility is the major reason leading to difficulty at calving. However, dystocia can result from other causes that interfere with the expulsive forces needed to expel the calf. This includes: lack of uterine contractions (weak labour), incomplete dilation of the cervix and vagina due to stenosis and uterine torsion. Dystocia has negative impacts on the farm, the cow and the calf. It is an undesirable reproductive event resulting in increased risk of calf morbidity and mortality, reduced fertility and milk production, as well as cow survival and consequently reduces farm profitability on dairy farms. Moreover, dystocia may have negative effects on reproductive performance, causing stillbirth, cow death, retained placenta, uterine infections, or increased involuntary culling, which have negative consequences for farm economics as well as for cow welfare. Thus to avoid its adverse effect every dairy should implement a dystocia monitoring program and employ management practices that limit the occurrence and impact of dystocia.

Full text

Journal of Reproduction and Infertility 7 (2): 63-74, 2016
ISSN 2079-2166
© IDOSI Publications, 2016
DOI: 10.5829/idosi.jri.2016.7.2.10457
Corresponding Author: Nejash Abdela, School of Veterinary Medicine, College of Agriculture and Veterinary Medicine,
Jimma University, Jimma, Ethiopia. Cell: +251924124547.
63
Risk Factors and Economic Impact of Dystocia in Dairy Cows: A Systematic Review
Nejash Abdela and Wahid M. Ahmed
12
School of Veterinary Medicine, College of Agriculture and Veterinary Medicine,
1
Jimma University, Jimma, Ethiopia P. O. Box. 307 Jimma, Ethiopia
Department of Animal Reproduction & AI, National Research Centre, Giza, Egypt
2
Absract: Reproductive health problems are one of the most important problems that affect the production and
productivity of dairy cows. Dystocia is also one of the reproductive health problems that cause considerable
economic loss to the dairy industry. The main aims of this manuscript were to review risk factors and economic
impact of dystocia in dairy cows. Dystocia is also defined as prolonged or difficult parturition and it is a
condition in which the first or, especially the second stage of parturition was markedly prolonged for more than
6 hr and the cow required assistance. There are different causes and risk factors associated with dystocia in
dairy cattle which can result from both maternal and foetal factors. Breed parity, weight and condition of cow
at calving, sex and birth weight of calf, malpresentation, multiple calving can be a risk factors for dystocia.
Foeto-pelvic incompatibility is the major reason leading to difficulty at calving. However, dystocia can result
from other causes that interfere with the expulsive forces needed to expel the calf. This includes: lack of uterine
contractions (weak labour), incomplete dilation of the cervix and vagina due to stenosis and uterine torsion.
Dystocia has negative impacts on the farm, the cow and the calf. It is an undesirable reproductive event
resulting in increased risk of calf morbidity and mortality, reduced fertility and milk production, as well as cow
survival and consequently reduces farm profitability on dairy farms. Moreover, dystocia may have negative
effects on reproductive performance, causing stillbirth, cow death, retained placenta, uterine infections, or
increased involuntary culling, which have negative consequences for farm economics as well as for cow
welfare. Thus to avoid its adverse effect every dairy should implement a dystocia monitoring program and
employ management practices that limit the occurrence and impact of dystocia.
Key words: Dairy Cow Dystocia Foeto-Pelvic Incompatibility Reproductive Health Problems Risk
Factors
INTRODUCTION potentially useful cows [5]. Thus, reproductive disorders
Ethiopia is known to have huge number of livestock production and productivity of dairy cows [6].
population [1]. Despite the huge livestock resource, the Dystocia is one of the important reproductive health
contribution for the economic aspect of the country is still problems of dairy cows that is commonly known as
lowest. Low economic returns from these resources are difficult calving and defined as prolonged or difficult
associated with several factors such as diseases, poor parturition [7]. It has been estimated that between 2 and
management and low genetic potential of indigenous 23% of cows in a herd experience difficult calvings that
breeds. Among which, reproductive health problems require farmer or veterinarian assistance [8]. There are a
cause considerable economic loss to the dairy industry variety of risk factors for dystocia such as breed, parity,
[2-4] due to slower uterine involution, prolonged inter weight and condition of cow at calving, sex and birth
conception and calving interval, negative effect on weight of calf, malpresentation, multiple calving and year
fertility, drop in milk production and early depreciation of and season of calving [9]. Foeto-pelvic incompatibility is
are one of the most important problems that affect the

J. Reprod. & Infertility 7 (2): 63-74, 2016
64
the major reason leading to difficulty at calving. However, Dystocia occurs when there is a failure in one or more
dystocia can result from other causes that interfere with
the expulsive forces needed to expel the calf. This
includes: lack of uterine contractions (Weak labour),
incomplete dilation of the cervix and vagina due to
stenosis (Narrowing and stiffening of the tissue) and
uterine torsion [10]. Dystocia is much more common in
primiparous than in multiparous cows [3-7] due to their
smaller stature and the slow maturation of pelvic
dimensions [11] but primary risk factors for dystocia are
different in primiparous and multiparous cows [12].
Dystocia is an economically important and major
problem in the dairy industry [13]. The total economic
costs attributable to a severe case of dystocia have been
estimated at up to _500 per case [14]. It is associated with
approximately 50% of calf mortality cases at birth [8] but
can also have a profound influence on cow performance
[15]. Dystocia is an undesirable reproductive event
resulting in increased risk of calf morbidity and mortality
[12, 16] reduced fertility [17, 18] and milk production
[13, 14, 19, 20] as well as cow survival [16, 21]. Moreover,
dystocia may have negative effects on reproductive
performance, causing stillbirth, cow death, retained
placenta, uterine infections, or increased involuntary
culling [12, 22]. The Other consequences of dystocia
include veterinary fees, extra labor and other management
costs [13]. Dystocia is also a welfare problem of cows and
calves. It causes pain or pain and injury to the cow.
Therefore, it directly leads to poor welfare in cows [23].
The motivation for this paper arises from recognition of
the above situation of dystocia and its serious economic
impact dairy cow. Therefore, the objectives of this
systematic review were to review the risk factors of
involved in dystocia and it economic impacts in dairy
cow. Furthermore, the paper highlights the current Status
of dystocia in Ethiopia.
Definition and General Aspect of Dystociain Dairy Cow:
There is a wide range of definitions for dystocia ranging
from need for assistance to considerable force or surgery
to extract the newborn [8, 10]. The term dystocia is from
the Greek ‘dys’ meaning difficult and ‘tokos’ meaning
birth. Eutocia or normal calving may be defined as a
spontaneous calving of normal duration [24]. Dystocia is
commonly known as difficult calving and defined as
prolonged or difficult parturition is a problem most dairy
producer’s encounter [7]. It is a condition in which the
first or especially the second stage of parturition was
prolonged markedly for more than 6 h and the cow
required assistance [25].
of the three main components of calving; expulsive forces,
birth canal adequacy and foetal size and position. While
all types of dystocia may occur in both heifers and older
cows, the predominant types and risk factors differ
between these parity groups. In heifers the primary types
of dystocia, in descending order of importance, are
oversized calves, abnormal foetal position and failure of
the vulva to dilate. In older cows, the primary types of
dystocia are abnormal foetal position, oversized calves,
multiple foetuses, uterine inertia, uterine torsion and
failure of the cervix to dilate. The dystocia rate can be up
to three times greater in heifers compared to older cows
[26].
There are several ways to assess difficulty at
parturition (Also referred to as calving ease in cattle).
Categorical scoring scales that allow for different degrees
of difficulty are commonly used across species with
ordinal scales with 3 to 5 rating points being popular in
cattle [8]. Lower scores are usually given to the easiest
births (Also called eutocial) and highest scores to the
most difficult ones. For example, in the Iran, dystocia
evaluations in the Holstein Friesian breed are currently
performed using the following 5 point scale: 1 =
unassisted, score 2 = slight assistance, score 3 =
considerable assistance, score 4 = considerable force
needed and score 5 = caesarian [27]. On the other hand, in
the UK, genetic evaluations in the Holstein Friesian breed
are currently performed using the following 4 point scale:
“1 = easy; 2 = assisted; 3 = difficult; 4 = vet assisted” [28].
The evaluation of costs associated with dystocia scores
enables dairy producers to predict the average future
economic loss when an incident of dystocia is reported in
the herd, allowing the producer to evaluate the relative
importance of dystocia in individual herds [10].
Causes and Risk Factors of Dystocia: There are different
causes and risk factors associated with dystocia in dairy
cattle which can result from both maternal and foetal
factors [29]. The maternal causes of dystocia are
considered to be arising either because of the
constriction/obstruction of the birth canal or due to a
deficiency of the maternal expulsive force [29, 30]. The
constriction/obstruction of the birth canal can result in
maternal dystocia and can be due to pelvic abnormalities,
vulvar or vaginal stenosis, neoplasms of the vagina and
vulva, vaginal cystocoele, incomplete cervical dilation,
uterine torsion and ventral dis- placement of the uterus.
An uncommon cause of constriction of birth canal is
carcinoma of urinary bladder. Pelvic abnormalities of the
mother that can result in dystocia include small size of the

J. Reprod. & Infertility 7 (2): 63-74, 2016
65
pelvis pelvic deformities or exostoses, osteomalacia and 13% per additional kg of the calf’s birth weight and
hypoplasia of vagina and vulva [29]. Moreover, the cows decreased by 11% for an increase of 1 dm of the pelvic
with milk fever are developing dystocia 6 times more than size of the dam. Male calves, who are generally heavier at
that of normal cows. This is because of a reduced ability birth, are at higher risk of dystocia. Calves having high
of smooth and skeletal muscle contraction causes for birth weights above 42kg and dams with a small pelvic
cow’s long period in labour, which predisposes to size are particularly at risk of dystocia [39].
dystocia [31]. Foeto-pelvic incompatibility is largely influenced by
Fetal Causes of Dystocia Include: Abnormal fetal pelvic area available at birth is affected by the size of
presentation or position, fetal monsters, persomus pelvis but also by fatness of the dam which might partially
elumbus and fetal oversize. An abnormal fetal position is obstruct the birth canal. The calf ’s physical factors
described as any position that is not in the “cranial contributing to a size mismatch between the calf and the
longitudinal presentation and in dorsosacral position, dam may include a calf of a big size or malpresentation.
with the head, neck and fore limbs extended [32]. Even These morphological factors are themselves dependent
thouth Foeto-pelvic incompatibility (FPI) is the major upon different variables including the age, breed and
reason leading to difficulty at calving, dystocia can result parity of the dam, twinning, the sex and weight of the calf,
from other causes that interfere with the expulsive forces the sire and breed of the calf as well as the nutrition of the
needed to expel the calf. This includes: lack of uterine dam during gestation [8, 9, 13]. In order to avoid cases of
contractions (Weak labour), incomplete dilation of the FPI, it is particularly important for the animal caretaker to
cervix and vagina due to stenosis (Narrowing and mate primiparous animals with bulls that are not expected
stiffening of the tissue) and uterine torsion. Risk factors to sire very large calves. This can be achieved by making
for weak labor include hormonal imbalances such as an informed choice on their genetic potential for their
reduction in plasmatic oestradiol concentration, high expected ease of calving [13].
levels of oestradiol-17ß at parturition [33] or high ratios of
corti- sol to progesterone. These imbalances can decrease Foetal Malposition: foetal malposition occurs at a low
expression of oxytocin receptors in the uterus as well as prevalence (<5%), but It is the most common cause of
changing the preparation of the soft tissues, causing dystocia in older cows accounting for 20 to 40% of cases
weak uterine contractions and weak dilatation of soft [38]. Abnormal foetal position most commonly presents as
tissues [10, 33]. Twin calves are a risk factor due to the posterior malpresentation, foreleg malposture, breech
increased possibility of malpresentation. In addition over- malpresentation or cranial malposture. Malpresented
and under-condition of the dam are also risk factors [8]. calves have a two-times higher risk of dystocia and a five-
Regardless of breed, twins, bull calves and heavier calves time higher risk of stillbirth [40].
have an increased risk of experiencing dystocia [34, 35].
Furthermore, Genetic, environmental and management Failure of the Expulsive Forces: Failure of expulsive
factors have varying degrees of influence on dystocia forces could result because of the failure of abdominal or
[8, 33, 36]. The most common risk factor for dystocia will uterine expulsive forces. The condition where the uterine
be discussed as follows. expulsive forces fail to deliver a fetus is known as uterine
Foeto-Pelvic Incompatibility: Most commonly dystocia fetus out of the birth canal does not follow because of
results from a physical incompatibility between the pelvic lack of contractions in the uterus [29, 41]. Uterine inertia,
size of the mother and the size of the calf at birth, also where the cervix is fully dilated but uterine contractions
called foeto-pelvic incompatibility (Or FPI) [8]. Because of are too weak to expel the foetus, is associated with
this, a high calf birth weight is known to be an important approximately 10% of all dairy cattle dystocia, primarily in
risk factor for dystocia, as well as the choice of sire, breed older cows [42]. Uterine inertia is classified conventionally
and length of gestation. It also follows that male calves into primary and secondary uterine inertia [29].
are also more likely to experience a dystocial birth because In primary uterine inertia cervical dilation occurs and
of their higher birth weight [37]. Calf birth weight and the fetus is in normal presentation, position and posture
maternal pelvic size account for 50 and 5-10% of the but it is not delivered due to lack of uterine contractions.
phenotypic variance in dystocia, respectively [38]. In a The process of birth begins but do not continue into
study on Holstein cattle, Johanson and Berger [34] second sage labor. The most common cause of primary
indicated that that the incidence of dystocia increased by uterine inertia in dairy cows is considered to be
2
the weight and morphology of the dam and the calf. The
inertia. The uterus quietens and the progression of the

J. Reprod. & Infertility 7 (2): 63-74, 2016
66
hypocalcaemia [43] with the animal showing signs of milk twisting of the uterus on its longitudinal axis. The exact
fever as calving is about to begin. Over distension of the etiology of uterine torsion is poorly under stood. It
uterus because of dropsical fetal conditions, general appears that instability of the uterus during a single horn
debility and environmental disturbances are other causes. pregnancy and inordinate fetal or dam movements
A few of the less common causes described by Biggs and probably are the basic reasons for rotation of the uterus
Osborne [44] include inherited weakness of uterine on its own axis [51]. The gravid uterus rotates about its
muscle, toxic infections, myometrial degeneration, senility long axis, with the point of torsion being the anterior
and nervousness. vagina just caudal to the cervix (Post cervical torsion). It
According to Arthur et al. [41], Secondary uterine is probable that pregnancies occurring in the left horn
inertia occurs due to exhaustion as a result of dystocia. may be rotating towards the left side, especially when
When the uterine musculature becomes exhausted rumen is partially filled. The degree of torsion is generally
subsequent to failure of delivery of a maldisposed or 90 to 180 although it can occur up to 360 or even
oversized fetus or due to obstruction in the birth canal, more. Torsions up to 540 [52] or 760 [53] have been
then the condition is known as secondary uterine inertia. recorded. Because of the rapidity of fetal death that
The contractions in the uterus then stop or become weak ensues following torsion and the uterine adhesions with
and transient. The animal shows no progress in visceral organs that develop, uterine torsion must be
parturition after the second stage of labor. The fetal considered an emergency. Less commonly the point of
membranes are ruptured and the cervix dilated. If dystocia torsion is cranial to the cervix (Pre-cervical torsion),
is prolonged without fetal delivery, the fetal fluids are Uterine torsion during pregnancy, at parturition, or post-
expelled out and the uterus contracts tightly around the partum is one of the complicated cause of maternal
fetus. It is necessary to correct the primary cause of dystocia both in cows and buffaloes culminating in
dystocia and deliver the fetus. Doses of oxytocin must be death of both the fetus and the dam if not treated
given after fetal delivery to regain uterine contractility. early [29]. The intermediate risk factors for torsion of
Secondary uterine inertia invariably results in retention of uterus are excessive foetal movement during stage one
the placenta [29]. of calving as the foetus adopts the birth posture,
Failure of the Cervix to Dilate: The incidence of cervical abdomen in some dairy breeds. Ultimate risk factors
dystocia was seen to be from 11.1 to 16.7 percent in cows. include foetal oversize and gender, debility and
Animals with delivery problems associated with the cervix insufficient exercise [49].
are those that had already delivered many calves [45]. The
dilation of the cervix at the time of delivery of fetus is Economic Impacts of Dystocia in Dairy Cow:
essential for the easy passage of the fetus. A wide variety Several studies have demonstrated the adverse effect
of changes in the hormonal milieu [46]. Enzymatic dystocia has on the survival, health and production of
loosening of fibrous strands by elevated collagenase and calves and dams [12, 18, 39]. Dystocia is an undesirable
the physical forces of the uterine contractions and fetal reproductive event resulting in increased risk of calf
mass are considered to be responsible to effect sufficient morbidity and mortality [12, 16,] reduced fertility [17, 18]
dilatation of the cervix during parturition in the cow [47]. and milk production [13, 14, 19,] as well as cow survival
An increase in inflammatory cytokines during parturition [16]. The total economic costs attributable to a severe
is known to effect dilation [48]. Cervical non-dilation can case of dystocia have recently been estimated at up to
occur because of the failure of any of the mechanisms _500 per case [14]. In order of descending ?nancial
responsible for dilation described above or spasm of the importance, dystocia impacts production (41% of costs),
cervical muscles or some other poorly understood fertility (34%) and cow and calf morbidity and mortality
mechanisms and results in dystocia [29]. (25%), excluding costs associated with increased culling,
Uterine Torsion: Uterine Torsionis relatively uncommon According to De Maturana et al. [55], calvings needing
(Approximately 5% of dystocia, primarily in older cows) assistance or surgery increase culling risk by 18% when
but appears to be increasing in prevalence (10%) in compared to unassisted calvings. Cows with easy
veterinary assisted dystocia [49]. Furthermore, its calvings experience 2.5 more productive life months
incidence is considered to be higher in buffaloes than cows having difficult calvings ($54 opportunity
compared to cows [29, 50]. Torsion of uterus usually cost). Thus, a difficult birth can negatively impact the
occurs in a pregnant uterine horn and is defined as the health, performance and survival of dairy calves, so
increased uterine instability at term and possibly a deeper
veterinary costs and other management costs [54].

J. Reprod. & Infertility 7 (2): 63-74, 2016
67
reducing overall levels and severity of dystocia is although some authors seem to find a deleterious effect
important to animal welfare as well as to the economics of on the overall lactation of cows [10, 54] some studies have
the farm [37]. suggested that these effects disappear beyond 14 days in
Poor Survival in the Lactation: Dystocia can lead to the Furthermore, the degree of difficulty from which milk
death of the cow in the most severe cases usually losses are reported ranges from slight degrees of difficulty
occurring within 48 hr [56]. Even beyond those 48 hr, [54] up to only in severe cases when surgery is needed
cows that have experienced dystocia are more likely to die [18]. Moreover, the magnitude of losses has been
or be culled in early lactation and over the lactating period suggested to be greater with increasing degrees of
[18, 54, 57]. Moreover, the fear that the animal might difficulty [54]. However, the pattern with which milk
experience difficulty at her next parturition may increase losses vary is not always obvious and other factors such
weight to the farmer’s decision to cull a dystocial cow as the overall yield or parity of the cow [61] might
[39]. influence it. As well, it is common for studies looking at
Lengthened Labour, Uterine Health and Fertility: their datasets to animals with full lactations or that have
Gaafar et al. [20] indicated that high incidence of survived until a certain lactation stage.
dystocia can adversely effect the reproductive
performance of dairy Friesian cows. The first estrus, Feed Intake and Metabolic Dysfunction: Cows that
first service, service period, days open and calving experience dystocia alter their feeding behavior beginning
interval were significantly longer in cows that exhibited 3 d before calving and standing behavior beginning 12 hr
dystocia as compared to normal cows. Furthermore, before calving compared to cows that calve without
their results have indicated that dystocia led to assistance [63]. Thus, an improved understanding of how
increasing the service interval, service period, days dystocia impacts cow behavior will aid in the development
open and calving interval. Cows experiencing difficulty of housing practices that accommodate cows at-risk for
at birth are more likely to suffer from postpartum experiencing difficult calving. During the lactating period,
diseases such as metritis, retained placenta and milk dry matter intake was shown to decrease in cows that had
fever [58]. This could be explained by the possibility experienced dystocia in the months postpartum [64] as
of microbial contamination during assistance [59] compared to cows that calved normally, but this was not
combined with a depressed immune status during the seen in the first two days postpartum [63]. This could
peripartum period. This highlights the importance of relate to lower milk production observed in dystocial
good hygiene when intervention at calving is required. animals but also to the greater losses in weight and body
Immunodeficiency is probably enhanced in dystocial condition score found in dystocial cows during their
cows as a consequence of the increased duration of subsequent lactation [19]. This may be related to changes
labour and the subsequent higher cortisol levels [60]. An in the metabolic function and lower immunocompetency
increase in the number of days open, the number of in these animals [39].
services to conception and a delay to first service has The experience of dystocia in Holstein dairy cows is
been shown after dystocia [17]. This impaired fertility after also associated with haematological changes at delivery
dystocia is thought to contribute to 30% of the cow relating to hepatic function. For example, dystocial
related costs of dystocia [54]. Gaafar et al. [20] indicated Holstein heifers had higher cortisol, cholesterol, glucose,
that the incidence of dystocia resulted in a significant high density lipoprotein (HDL), triglycerides, creatinine
reduction in conception rate, where the conception rate at and vitamin A levels than eutocial animals, which might
90, 120 and 150 days and the entire lactation for cows that reflect higher calving stress in these animals [60]. It is
exhibited dystocia reduced by 10.7, 11.5, 12.02 and 12.5% possible that such stress but also exhaustion, pain and
as compared with normal cows, respectively. In general human intervention during delivery may contribute to
and poorer fertility is one economic impact of dystocia reduced or delayed maternal care of the calves in the first
in dairy cow [55]. hours postpartum, as observed in ewes [65, 66].
Poor Milk Production: Several studies have implicated Effects of Dystocia in the Dairy Calf: In addition to being
dystocia as a contributing factor to reduced milk yield [13, a difficult experience for the cow, hard calvings are
14, 19, 20, 54, 55]. It is not clear however, how long the traumatic for the calf. Immediate physiological effects of
adverse effect on milk production lasts for. In fact, dystocia can include: Stillbirth, Hypoxia (Deprived of
milk (DIM) [61] 90 DIM [62] or six monthpostpartum [18].
milk production losses after a difficult calving to restrain

J. Reprod. & Infertility 7 (2): 63-74, 2016
68
adequate oxygen supply), acidosis, potential trauma, Prevention and Management of Dystocia in Dairy Cow:
impaired temperature regulation and reduced absorption
of IgG from colostrum [67]. Dystocial calves may not
thermoregulate properly and achieve lower passive
immunity. This may relate to higher morbidity [12] and
possibly altered growth [68]. Dystocia results in a more
severe acidosis than a normal, unassisted birth due to the
increased time of hypoxia and anoxia during parturition.
The longer the calves are in the transition between the
uterine and extrauterine environment, the greater the
probability of anoxia, resulting in a more severe acidosis.
Dystocial calves frequently have a depressed central
nervous system, which reduces the stimulation for
respiration. This depression also results in decreased
physical activity and might prevent calves from standing
or taking longer than normal to stand [35].
Animals born from difficult births are more likely to
fail in transition from foetal life to extra-uterine life and
become stillborn or die within the few days of life [26, 34].
Approximately 50% of stillbirths are a direct result of a
difficult calving [67]. Dystocial stillbirths usually result
from internal and external trauma [69, 70]. But also from
prolonged hypoxia (Deprivation of adequate oxygen
supply) [39].
Dystocia calves that make it through the critical first
few days of life are at increased risk for health issues
throughout calfhood. Compared to heifer calves born to
dams having no assistance, calves born to dams having
dystocia experience increased: Treatment of respiratory
disease, Treatment of digestive disease, Overall heifer
mortality before weaning and before first service [71].
Study has identified detrimental side effects for the “hard-
pull calf” that grows up to become a member of the
milking herd. Compared with non-assisted calves, those
delivered with assistance experience a delay in reaching
peak milk yield and Show a loss in milk production as
adult heifers [72]. Reduction in survival rates and milk
production were seen when the calf reach an adult age
[71-73].
The study by Lombard et al. [12] used a three-level
dystocia scoring system with 1 indicating a normal,
unassisted delivery; 2 indicating assistance by one
person not using mechanical means; and 3 indicating that
two or more people were required and mechanical or
surgical assistance was required. In this study, the
percentage of stillbirth calves (More correctly perinatal
mortality, or calves dying at or immediately near
calving) increased as the dystocia score increased. Only
3.2% of unassisted calves (Score of 1) were stillborn
compared with 8.4% of calves with a score of 2 and 37.2%
of calves with a score of 3 and overall, 8.2% of calves
were stillborn.
Dystocia causes a huge loss in dairy cattle herds and
cannot be predicted but can be reduced by superior
management of one’s herd [32]. Its management is easier
if the specific physical traits, environmental or managerial
situations that influence its prevalence are identified.
Steps that can be taken to achieve a specific diagnosis
include weighing replacement heifers at intervals from
weaning to calving as two-year-olds, measuring yearling
heifer pelvic areas, weighing calves at birth, recording calf
birth dates, monitoring and recording pasture quality and
quantity, monitoring and recording daily rainfall figures,
collecting suitable samples to assess trace element
status and recording comments for all assisted calvings.
With this information, prospective and retrospective
assessments can be made [74].
Preventative management strategies includes
ensuring that bulls used for yearling mating are of the
same breed, have low birth weight estimated breeding
values (EBVs) or are known not have a large mature size
[75]. Other recommended strategies are keeping heifers
growing at all times, especially during the first half of
pregnancy and avoiding obesity at calving. Replacement
heifers should be well developed and fed adequately to
reach 65% of their mature weight at breeding. Parturient
cows should be observed no less frequently than every
3 hours and delivery should be assisted if the first or
second stage of labor is prolonged”. [32]. If the amnion
sack is ruptured, indicated by a release of allantoic fluid
and the cow or heifer has not given birth within two hours
of the sack breaking, then assistance will be needed [32].
Furthermore, since genetic selection could improve
calving performance, it is important to include calving
traits, such as dystocia, in genetic evaluations [73].
In general dystocia control measures include
avoiding matings that cause big calves, preventing heifer
obesity at calving and most importantly, keeping heifers
growing at all times, especially during the first half of
pregnancy. Under-nutrition at any stage can retard pelvic
growth. Under-nutrition in early pregnancy may increase
size and efficiency of the placenta, which
disproportionately increases fòetal growth when adequate
nutrition is restored [75].
According to Jason et al. [35] the prevalence and
effects of dystocia can be reduced in three ways:
Prebreeding management: select sires for calving
ease and dams for Adequate pelvic size (Dam
selection has never been done in the dairy Industry),
breed heifers of recommended height and weight and
provide Optimal nutrition during pregnancy.

J. Reprod. & Infertility 7 (2): 63-74, 2016
69
Calving time: ensure that calving areas are CONCLUSION
comfortable and as stress free as possible and
provide assistance when needed using proper
Techniques and procedures.
Neonatal assistance: providing maternal and
additional care as needed to Stimulate respiration
Maintain body temperature (Thermoregulation) and
Increase blood volume via colostrum
Status of Dystocia in Ethiopia: Reproductive problems of
dairy cow are common in Ethiopia. In the country, diary
cattle are maintained under different production systems
[76]. The differences in management (Production) systems
and environmental conditions under which cattle are
maintained could greatly affect the occurrence of
reproductive health problems. It has been indicated that
reproductive problems result in considerable economic
losses to the dairy industry and are the main causes of
poor productive performance of smallholder dairy farms
[3]. A number of researchers have reported the prevalence
dystocia in dairy cow from different area of Ethiopia and
most of the reported prevalence of in dairy cows ranges
from 2.9% to 11.6%. Tables 1 summarize the prevalence of
dystocia in dairy cow from 1996- 2015. The lowest
prevalence (2.9%) was reported from Central Ethiopia,
Bishoftu by Hadush et al. [77]. Highest prevalence
(11.6%) was reported from Mekelle by Mekonnin et al.
[78]. Micheal [79] also reported 9.7% from Awassa and
Haile et al. [80] reported 5.9% from Hosanna
Table 1: prevalence of dystocia in dairy cow in Ethiopia
Area Prevalence Reference
Hosanna (Southern Ethiopia) 5.9% [80]
Debre Zeit (Central Ethiopia) 2.9% [77]
East Shoa 3.3% [81]
East Wollega 6.7% [82]
Borena Zone 3.4% [5]
Bedelle (South western Ethiopia) 6.6% [83]
Holleta 5.5% [84]
Holleta 7.8 % [85]
Alage 3.1% [86]
Mekelle 3.7% [87]
Awassa 9.7% [79]
Debre Zeit 5.8% [88]
DebreZeit 5.79% [89]
Kombolcha (Northeast Ethiopia) 7.75 % [4]
Mekelle 11.6% [78]
Adama 6.95% [3]
Holleta 7.5% [90]
Holetta 7.8% [91]
Awassa 9.65% [92]
Kombolcha 4.3% [93]
Jimma 3.8% [94]
Dystocia is one of the reproductive health problems
of dairy cows characterized by prolonged or difficult
parturition. It is economically important and major problem
in the dairy industry. Dystocia has negative impacts on
the farm, the cow and the calf. Dystocia is associated with
a reduction in milk yield in the subsequent lactation and
poorer cow fertility and health, which have negative
consequences for farm economics as well as for cow
welfare. With respect to the calf dystocia is associated
with higher mortality in the immediate post-natal period
and it is related with 50% of preweaned calf losses.
However, there has been less attention paid to the effects
of a dystocial birth on the surviving calf. Thus, growth,
survival, health and welfare of the calf may be adversely
affected. Obviously, based on the frequency of
occurrence and the impact, dystocia should be an area of
great concern for the dairy industry. While it is not
possible to eliminate dystocia, adequate management of
heifers during their development (Adequate feeding,
selection of a sire with a negative expected progeny
difference for birth weight) and close observation of cows
and heifers during calving are essential for reducing calf
losses. To avoid dystocia adverse effect, every dairy
should implement a dystocia monitoring program and
employ management practices that limit the occurrence
and impact of dystocia. It is also very important to avoid
birth injuries and infection of the reproductive tract during
assistance, which is more likely to occur in cows with
dystocia. Dystocia significantly decrease lactation
performance, so in any economic evaluation of dystocia,
not only the lost calf, veterinary costs, the reduced
survival and the increased days open should be taken
into account. Finally genetic selection could improve
calving performance thus, it is recommended to include
calving traits, such as dystocia, in genetic evaluations.
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