Before considering the causes
and treatments for various calving problems, the adverse affects of
all forms of "assistance" must not be overlooked as they can prove
very costly in terms of delay to subsequent re-breeding. There is
no point in delivering a huge Charolais bull calf which looks great
at sale time if the cow is barren for next season. The impact of
level of assistance and subsequent breeding performance is
illustrated in the table quoted below. This exercise could produce
some sobering results in many herds. It is not unusual for a farmer
to change to an easy-calving bull and comment that they have not
only never touched a cow at calving time but that there is much
less scour and other health problems in the calves.
Fig 1: An easy-calving bull has major health
and welfare benefits on beef farms.
Fig 2: No assistance and exemplary hygiene
Number of cows
Assisted by vet
After Caldow and others (2005)
There are three key factors to bear
in mind before assisting a cow to give birth:
1. Patience: Much
damage can be caused by interfering too soon in the birth process.
Disturbing the cow during first stage of labour can delay dilation
of the cervix. A cow can be safely left alone for an hour after the
water bag has ruptured and in the case of a heifer this period can
be extended to three or four hours.
Fig 3: Disturbing the cow during the first
stage of labour can delay progress of the birth
2. Hygiene: Not
only must the maternity accommodation be clean and well bedded, the
equipment to be used should also be clean and well maintained.
Lastly, it is important that the farmer has clean hands or wears
Fig 4: Exemplary hygiene in the calving
Adequate lubrication is necessary to help in the delivery of the
calf. Pure soap flakes (without detergent) or any of the
commercially available obstetrical lubricants aid the passage of
the calf through the birth canal.
Pregnancy in the cow is around 285
days but is influenced by single or twin calves, and the sire.
Gestation length and calf birth weight are calculated for many
sires used in artificial insemination programmes. These estimated
breeding values (EBVs) are a very important method to reducing
calving difficulties and can be incorporated into beef herd
programmes using artificial insemination.
Imminent parturition is indicated
by separation from other cows in the group for up to 24 hours
before calving, udder development, accumulation of colostrum, and
slackening of the sacro-iliac ligaments.
Fig 5: Imminent parturition is indicated by separation
from other cows in the group for up to 24 hours before calving and
slackening of the sacro-iliac ligaments
The birth process
The birth process is divided into
1. First stage
First stage labour is represented
by dilation of the cervix (neck of the womb) which may take 3 - 6
The cow typically will continue to
separate herself from herd-mates into a corner of the field or
barn, with alternate lying/standing behaviour. A thick string of
mucus is often observed hanging from the vulva. Bouts of abdominal
straining occur more frequently, usually every 2-3 minutes, towards
the end of first stage labour. In a case of uncomplicated anterior
parturition, this increased activity coincides with extension of
the calf's forelimbs.
Fig 6: A thick string of mucus is often observed
hanging from the vulva.
2. Second stage
Second stage labour is represented
by expulsion of calf (calves), and takes from 5 minutes to several
hours. There is rupture of allanto-chorion (water bag) with a
sudden rush of fluid. The amniotic sac appears at the vulva and
ruptures at this stage. Powerful reflex and voluntary contractions
of abdominal muscle and diaphragm ("straining") serve to expel the
calf. Occasionally, the amniotic sac may not rupture and results in
death of the calf due to asphyxiation. This scenario is not
uncommon in twin births.
Fig 7: Rupture of allanto-chorion (water bag)
with a sudden rush of fluid.
Fig 8: Appearance of hooves in amniotic
Fig 9: Amniotic sac ruptures, feet exteriorised
and appearance of muzzle at vulva
Figs 10 (above) & 11 (below) Powerful
reflex and voluntary contractions of abdominal muscle and diaphragm
("straining") serve to expel the calf
3. Third stage labour
Third stage labour is completed by
expulsion of foetal membranes (afterbirth or cleansing) which
usually occurs within 2-3 hours after birth of the calf.
The safety of everyone present is
very important with excitable and potentially aggressive beef cows,
and some heifers. Many farmers routinely calve all cows in cattle
stocks which is not ideal for several reasons but may be the best
compromise with an aggressive cow and limited staff.
Advantages of calving cows in
calving cows in stocks
Cow unable to lie down and
strain, to help expel the calf
Cow may become cast and be unable
Cow may fall down during delivery
of the calf causing injury to the calf
After correction of the calf's
malposture and fixing the calving ropes when the cow is secured in
the cattle stocks it is preferable, where safe, to halter the cow
and release her into a clean calving pen. The free end of the
halter should be tied low down to a substantial post allowing
approximately 1.5 m of lead rope because delivery of the calf is
easier when the cow is able to lie in her side and strain using all
her abdominal muscles.
Alternatively, the cow can be
restrained behind a gate hinged 75 cm from the corner of the
calving pen and the halter applied before progressing. Such a
system works best for dairy cattle and quiet beef cows.
Fig 12: The cow can be restrained behind a gate hinged
75 cm from the corner of the calving pen and the halter applied
Several factors conspire to result
in conflicting advice regarding calving accommodation.
Ideally, the calving pen should be
cleaned and disinfected between every occupant to prevent disease
transmission. The diseases most readily spread from dam to
offspring, and subsequent pen occupants are:
Good hygiene in the calving pen
will also reduce navel infections, joint ill and subsequent
episodes of calf scour. Mastitis and metritis (womb infections) in
the cow may also be reduced.
The disadvantages of such
meticulous hygiene standards are:
Cost of bedding materials
Number of calving pens required
during busy calving period
Loss of grip for cows recovering
from milk fever, and after periods of recumbency.
A compromise is to add large
amounts of clean dry straw between cows with the pen mucked out and
disinfected after 3-5 calvings - but note that this regimen is not
recommended for herds with Johne's disease (paratuberculosis) or
An ideal calving pen would be
fitted with a light and power source, a water bowl and facilities
to milk the cow in the pen in case she is not in a fit condition to
move out after having given birth. An outwardly opening gate is
also an advantage.
Fig 12: Cattle crush for safe restraint of beef cows
during investigation of potential calving
Fig 13: Individual calving boxes adjacent to the
cattle stocks on this beef farm.
Most vets and farmers use calving
ropes rather than chains to apply traction to the legs; calving
chains are much more readily disinfected. Two short ropes,
preferably different colours, can be used for the legs, and a
longer rope as a snare to correct head malposture.
Almost without exception, calving
ropes are not adequately cleaned and disinfected between calvings.
Typically, they are left hanging on a hook in the bulk tank room or
over the calving aid next to the cattle stocks. Calving ropes must
be cleaned of all gross debris after use and left in a veterinary
disinfectant for 10-15 minutes, dried, then stored in a clean
polythene bag until next use.
Fig 14: Almost without exception, calving ropes are
not adequately cleaned and disinfected between
With the calf presented in anterior
presentation (coming forwards), reasonable traction will deliver-
the calf when two people pulling can extend both front legs such
that the fetlock joints protrude one hand's breadth beyond the
vulva within 10 minutes' traction. Such movement of the calf's
forelegs represents extension of both elbow joints into the cow's
pelvis. Veterinary attention is necessary if greater traction is
applied without obvious progress and the elbows are not extended
With the calf presented in
posterior presentation (coming backwards) two strong people pulling
on calving ropes should be able to extend both hocks more than one
hand's breadth beyond the cow's vulva (calf's hindquarters now
fully within the pelvic inlet) within 10 minutes. Further traction
will deliver the calf safely.
There are two commonly used calving
aids. The more simple 'T' shaped aid (Fig 14), which is more
suitable for dairy breeds, has the advantage of applying traction
to the calf's legs alternately. The newer design aid (Fig 15) fits
over the pelvis of the cow and, because of the more rounded rear
end of the beef breeds is more suitable for use in these breeds.
Both generate traction forces in excess of four strong men. Calving
aids must be used with great care as nerve paralysis and hip lock
are common consequences of their mis-use.
Fig 15: Another design of calving
Calving machines must not be used
as levers when traction is applied. Such forces greatly exceed
those which are reasonable and have the potential to cause serious
damage to both cow and calf.
Calving aids must be regularly
cleaned and disinfected because they come into direct contact with
the cow's perineum and have the potential to introduce infection
into the uterus either directly or indirectly.
Some common obstetrical definitions
Presentation signifies the relation
between the long axis of the calf and the maternal birth canal. It
includes anterior or posterior longitudinal presentation, ventral
or dorsal transverse presentation.
indicates the surface of the maternal birth canal to which the
calf's vertebral column is applied. It includes dorsal, ventral and
right or left lateral position.
refers to the disposition of the moveable appendages of the calf
and involves flexion or extension of the cervical and limb joints,
e.g. bilateral hock flexion posture.
The calf's front legs must protrude
hand's breadth beyond the fetlocks after a maximum period of 10
minutes' traction (two people) to safely proceed; reconsider option
if greater traction necessary.
Two strong people pulling on
calving ropes should be able to extend the hocks more than one
hand's breadth beyond the cow's vulva (calf's hindquarters now
fully within the pelvic inlet) within 10 minutes.
Other guidelines include whether a
hand can be passed between the calf's head and the maternal pelvis
when both feet and the head are engaged within the pelvis,
conversely if a hand can be passed between the calf's tail head and
the maternal pelvis in posterior presentation.
Comparisons of the calf's
metacarpal/metatarsal bone diameter relative to external maternal
pelvis dimensions have little practical use.
Sire breed selection is important
but it is generally stated that there is as much within breed
variation in dystocia incidence of sired females than between
breeds. However, general, native breeds such as the Aberdeen Angus
have fewer calving problems than Charolais. Estimated Breeding
Values (EBVs) allow bulls to be selected with lower calf birth
weight and shorter gestation periods reducing dystocia risk. EBVs
with high accuracy are available for many AI sires and should be
considered in artificial breeding programmes.
Further practical information can
be found at a number of websites including: