Conditions of the Reproductive System

This page includes information about conditions of the reproductive system, including strategies to manage or avoid abortion and infertility. Conditions covered here include:

• Non-cycling cows
• Cystic ovaries
• Metritis
• Retained placenta (or RFMs)
• Endometritis
• Abortion/stillbirth
• Freemartins.

Non-cycling cows

What to look for

Cows that are not observed to be cycling either prior to or during the mating period.

Cause

Cows may not be observed to cycle for several reasons. These include:

• True anoestrus (non-functioning ovaries)
• Uterine infections
• Cystic ovaries
• ‘Silent heats’, i.e. where the cow ovulates but heat is not observed
• Poor heat detection
• Pregnancy.

Animals likely to be affected

Cows in low body condition score and first-calved heifers are most likely to be affected by true anoestrus.

In seasonal/split calving herds, late calving cows are also commonly affected by natural post-calving anoestrus.

Silent heats tend to be more common in larger herds and in higher producing cows.

Confirming the diagnosis

True anoestrus can be differentiated from other causes of non-cycling by a veterinarian using either palpation or ultrasound. Cows with anovulatory anoestrus have very small ovaries that lack normal structures (follicles and corpus lutea).

Treatment

There are various hormonal therapies that can be used to re-start the ovaries of cows with true anoestrus. These therapies can also be used effectively in non-cycling cows where the cause is silent heats or cystic ovaries.

For more information see “Non-cycling cows” in Fertility.

Risk factors

• Poor body condition at calving
• Suboptimal nutritional management between calving and start of mating
• Poor transition cow management
• Late-calving cows (split/seasonal) or short voluntary waiting periods (all-year-round)
• Other diseases such as uterine infection, milk fever, lameness, mastitis
• High production (silent heats)
• Larger herds (silent heats).

Prevention

Prevention of true anoestrus can be improved in two ways:

1. Improving nutrition strategies in the transition period and between calving and mating.
2. Eliminating late calving cows, i.e. improving fertility/calving pattern.

For more information on transition cow management and feeding cows well:

Feeding in early lactation page (Feeding & Nutrition Section)

Transition cow management page (Fertility Section)

For more information on managing calving pattern

Calving pattern page (Fertility Section)

Cystic ovaries

What to look for

Cows with cystic ovaries may be either non-cycling (most common) or have abnormally frequent cycling behaviour.

Cause

There are many interacting factors which lead to the development of cystic ovaries. These include nutritional stress, high production, age, genetics and underlying diseases.

Animals likely to be affected

Cystic ovaries are most likely to affect older, higher producing cows that have recently calved (1-2 months post-calving).

Confirming the diagnosis

Cystic ovaries can be diagnosed by a veterinarian using either palpation, ultrasound or laboratory tests. There are four different categories of cystic ovaries that require different treatments.

Treatment

There are various hormonal therapies that can be used depending on the type of cystic ovaries. Many of the treatments for cows with true anoestrus in non-cycling cows are also useful for treatment of cystic ovaries.

Risk factors

• Nutritional or other forms of stress
• High production
• Older cows
• Underlying disease.

Prevention

As there are many contributing factors to cystic ovaries, there are no specific prevention strategies. However, improving nutrition in the transition period and between calving and mating, as per non-cycling cow prevention, can be helpful.

Metritis

What to look for

• Foul smelling uterine discharge
• Reduced milk production
• Reduced appetite and noticeably ill, depressed, dull or lethargic
• High temperature
• In severe cases, cows may go down, be cold to touch and have sunken eyes caused by dehydration.

Cause

Metritis is caused by infection of the uterus and uterine wall with several different types of bacteria.

Animals likely to be affected

Cows of any age can be affected by metritis. Metritis usually occurs in the two weeks post-calving.

Confirming the diagnosis

Diagnosis can be made by considering the history of the cow, for example, recent calving, and observing the symptoms or by conducting a vaginal examination.

Treatment

Treatment of metritis usually requires injectable antibiotics and anti-inflammatories. Severely sick cows may also require IV fluid therapy.

Intra-uterine treatments such as pessaries or ‘wash outs’ are not recommended as they can cause further irritation to uterine tissues.

Risk factors

• Difficult or assisted calving
• Retained placenta (also known as retained foetal membranes or ‘RFM’)
• Damage to or contamination of the uterus during calving
• Other diseases such as going down around calving
• Poor transition cow management
• Twins or stillbirths
• Calving induction.

Prevention

Prevention of metritis is best achieved by addressing the risk factors above.

Good transition cow management will reduce the risk of metabolic diseases and calving difficulties. More information on transition cow management can be found here.

It is also important to calve cows on clean, dry pasture or on a clean, dry calving pad. Pasture or pads for calving must have minimal manure contamination. If more than two pats of manure are present per square metre, it is not clean enough for calving cows.

The calving area should be sheltered and well drained. Avoid pugging and mud. If water is visible on the surface or in gumboot prints, it is not dry enough for calving cows. If possible, heifers should be calved separately from the main herd. Heifers are more likely to be bullied and forced to calve in less suitable areas.

It is also important to practice good hygiene when assisting calving cows.

Retained placenta

Retained placenta may also be known as ‘retained foetal membranes (RFMs)’.

What to look for

Placenta that has not been delivered or come away 12 hours or more after calving.

Cause

Retained placenta is caused by a complex relationship between immune function, hormone production and uterine muscle contraction.

Animals likely to be affected

Cows of any age can be affected by retained placenta after calving.

Confirming the diagnosis

Diagnosis is usually made by observation of retained placenta. Many cows will also display signs of metritis.

Treatment

Removal of retained placenta should not be attempted until at least 3–4 days after calving.

If the placenta cannot be removed by very gentle pressure, it should be cut off at the level of the vulva to prevent 'wicking’ of bacteria into the uterus. Never pull on membranes to remove as this is likely to cause tearing and damage to the uterus.

Cows usually do not require any other treatment unless they are showing signs of illness, as antibiotics may interfere with the natural break-down process. Cows showing signs of illness should be treated as for metritis.

Risk factors

• Abortion
• Milk fever and other metabolic diseases
• Poor transition cow management
• Twin births
• Calving difficulties.

Prevention

As for metritis.

Endometritis

What to look for

• Pus-like discharge from the uterus
• Many cows will not show visible signs
• Unlike metritis, cows with endometritis are not usually sick.

Cause

Endometritis is caused by an infection of the inside of the uterus that does not penetrate the uterine wall, usually by bacteria called Arcanobacterium pyogenes.

Animals likely to be affected

Cows of any age can be affected by endometritis after calving.

Confirming the diagnosis

Diagnosis may be made in some cows when pus-like discharge from the uterus is observed.

Many cows will show no visible signs of endometritis, so routine-premating checks of the whole herd or at least at-risk cows is recommended. This can be done by examination with a vaginal speculum or Metricheck® device, which collects a small sample of vaginal discharge for examination.

Treatment

Treatment of endometritis may involve the use of intra-uterine antibiotics (Metricure®) and/or the use of hormonal therapies. Mild cases of endometritis will self-cure.

Risk factors

As for metritis.

Prevention

As for metritis.

Abortion and stillbirths

Occasional abortions occur in normal herds. However, when abortions and stillbirths are affecting more than 1% of late-pregnant cattle, they should be investigated by your veterinarian.

What to look for

• Observed abortion or abortion material, e.g. foetus
• Retained placenta in cows not due to calve
• Cows that were confirmed pregnant that do not calve
• Cows that were confirmed pregnant resuming cycling.

Cause

There are several possible causes of abortion in dairy herds including:

• Bacterial, e.g. salmonella, leptospirosis and vibrosis
• Viral, e.g. BVDV and IBR
• Parasitic, e.g. neospora or theileria
• Fungal
• Non-infectious, e.g. heat stress, nitrate toxicity or ingestion of foliage from Macrocarpa (cypress) or pine trees

Animals likely to be affected

The likelihood of abortions will depend on various animal factors such as age and immune status, as well as environmental factors such as exposure to Macrocarpa trees.

Confirming the diagnosis

Diagnosis of the cause of abortion usually requires laboratory examination of:

• Blood samples usually from several cows/heifers in the affected group
• Aborted calves
• Placenta.

Therefore, if abortions are observed, it is important to collect these materials and refrigerate as soon as possible to give the best chance of diagnosis. Most state agriculture departments have subsidies available for abortion investigations.

It is important to note that it can be difficult to pinpoint the exact cause of abortion in many cases, particularly if the appropriate samples are not available.

Treatment

Treatment requirements will depend on the cause of abortion. Cows that have aborted will be at higher risk of retained placenta.

Risk factors

• Failure to vaccinate or inadequate vaccination of heifers, cows and bulls
• Exposure to Macrocarpa (cypress) or pine trees especially in late pregnancy
• Dogs and/or poultry having access to paddocks (Neospora parasite)
• BVDV in the herd
• Suboptimal biosecurity practices.

Prevention

Appropriate preventative strategies will depend on the cause. Some general prevention strategies may include:

• Maintaining a closed herd (including bulls) wherever possible
• Vaccination for leptospirosis, salmonella, vibriosis, BVDV and IBR
• Restricting dogs and poultry from accessing pasture
• Avoiding paddocks which contain Macrocarpa (cypress) or pine trees in late gestation
• Careful management of forages to avoid nitrate toxicity
• Using artificial breeding (AI) only.

More information on the prevention of BVDV can be found here.

More information about dairy herd biosecurity can be found here.

Freemartins

Between 90% and 95% of heifers that are born a co-twin to a bull calf are freemartins. Freemartins are heifers with congenital abnormalities of their reproductive system and are infertile.

What to look for

Heifer calves born to twin pregnancies where one calf is male and one is female.

Vulva may appear abnormal with masculine characteristics such as coarse prepuce-like hair.

In some freemartins, external genitalia appear normal.

Cause

Freemartins occur when a heifer and bull twin share the uterus and blood supply. Male cells and hormones from the male twin cause abnormal development of the female twin’s reproductive organs. Male twins are unaffected.

Animals likely to be affected

Heifers that are born as a co-twin to a bull calf.

Confirming the diagnosis

In most cases, diagnosis can be made by a veterinarian by the presence of an abnormally short or absent vagina.

Freemartins do not possess normal reproductive organs and do not cycle so may not be detected until mating or pregnancy testing.

A blood test is also available that may be used to confirm the diagnosis in high genetic merit calves that have normal appearing external genitalia.

Treatment

There is no treatment for freemartins.

Early diagnosis is important to avoid too much investment in their rearing costs.

There are no problems associated with rearing freemartins for beef production.

Risk factors

Heifers that are born a co-twin to a bull calf.

Prevention

There is no specific prevention for freemartins. However, the likelihood of a cow conceiving twins is influenced by genetics, so selection for single pregnancies may be considered in herds with high numbers of twin births.

BVDV

For more information on BVDV visit the page.

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