Benefits of a post-calving vet check for herd health

A post-calving vet check not only helps prevent subclinical endometritis, but it also lets the farm vet keep track of a herd’s overall health status.

It is not just at-risk cows that are likely to be affected – every farm has its own specific risk factors affecting reproductive health.

See also: Uterine disease in dairy cows: Symptoms, causes and reducing risk

Endometritis is a low-grade bacterial infection that causes inflammation of the uterine lining.

Although cows with endometritis do not show signs of sickness, the infection still affects their fertility.

Fifteen years ago, vet James Marsden of Shropshire Farm Vets says he would regularly see “dirty” cows on routine fertility visits.

However, progress in finding and treating cases means that vets now focus on prevention, he says.

This involves optimising body condition, managing transition and minimising disease around calving.

Checking cows after calving is now used as an indicator of anything going wrong on-farm.

“A post-calving vet check is a useful diagnostic tool in conjunction with other farm factors, not in isolation,” he explains.

“We look at everything from nutrition to lameness control, or whether there are adequate environmental conditions for cows, such as cubicle space and ventilation.”

Additional risk factors include infectious disease such as Q fever, infectious bovine rhinotracheitis and salmonella.

© MAG/Shirley Macmillan

Timing

The earlier a post-calving check is carried out, the more likely it is that more cows in a herd may show signs of infection, says James: “You find a lot more in week one, and by four weeks post-calving, cows appear to have self-cured.

“Often, the best time to do a check is after two weeks. Timing is about being able to detect and treat infected cows at least four weeks before service to have them clean and cycling for breeding.”

However, he points out that a proportion of cows with endometritis can go on to develop subclinical endometritis.

“According to research, between 15-67% of dairy cows can be affected, depending on different farm risk factors,” he says, adding that it is not possible to tell which cows will self-cure and which may develop a long-term problem.

This is why James recommends discussing all farm-specific risk factors with the vet and working out the best timing for a post-calving check.

Rather than just selecting at-risk cows (those that are thin, older or retain their cleansing, or have ketosis, twins, a difficult calving, abortion or still birth) a whole herd approach is best.

Scoring system

He says some farms, for instance, with good fertility and few risk factors, may be able to wait until four weeks after calving to check if cows are clean.

A spring block-calving herd, on the other hand, where weather and grass growth dictate nutrition intakes (and cows must be fertile and cycling to maintain the calving block), may benefit from a check at two weeks.

By using a Metricheck device (a steel rod with a silicone cup at the end, which is inserted into the vagina) and a scoring system from 0 to 3 (1 to 5 in New Zealand where it was developed) for the discharge, vets can decide which cows will benefit from treatment, says James.

“Then we can track progress with a repeat visit, and re-scoring allows us to fine-tune treatment options.”

His practice has trained its vet tech to use the device. James operates in tandem with the vet tech when they work with a lot of cows, either on a palpation rail, or restrained in head yokes.

The vet tech first examines all cows put forward, marking those scoring higher than zero for James to carry out a full check.

This might involve scanning ovaries and the uterus to establish the severity of infection and deciding the appropriate treatment.

© MAG/Shirley Macmillan

Treatment

“If a farm has a good pregnancy rate – over 30% – and cows are cycling well but have low-grade endometritis two weeks post-calving, then we could check again to see if they have self-cured.

“But if the pregnancy rate is only 15% and you find cows are score one, it is not a risk worth taking to leave them untreated,” he says.

The simplest treatment, James says, is to use prostaglandin to get a cow back in heat if the vet has diagnosed a corpus luteum on the ovary.

This creates a “leaky” uterine wall, which then allows white blood cells in to attack any infection.

By giving two injections, two weeks apart, and allowing a couple of extra heats before the voluntary waiting period is up, infection will clear up naturally.

Where antibiotics are needed, the farm’s vet can prescribe the licensed intrauterine product, which is a single shot (Metricure) with zero milk withdrawal.

Analysing the cost-benefit of a veterinary post-calving check with or without treatment, James says time, effort and drugs must be weighed up against a lift in fertility or the risk of a potential drop in performance.

“It takes seconds to Metricheck and treat a cow in a palpation rail or yoke – I reckon we can do 50 cows an hour.”

He thinks a ballpark figure would be £100 extra profit for every 5% lift in pregnancy rate in an all-year-round calving herd.

For a block-calving herd, every 1% increase in the six-week in-calf rate is worth £1,000 for every 100 cows.