2009 September

Worms in Dairy Cattle

The important worms in our region are the small brown stomach worm (Ostertagia ostertagi), stomach hair worm (Trichostrongulus axei), lungworm (Dictyocaulus viviparus) and occasionally the small intestinal worm (Cooperia spp.).  Interactions between age, body condition, nutritional status, pasture and weather conditions determine which animals and how badly, they are affected by worms.

 

Stomach worms

The eggs of the stomach worms are passed onto pasture where they hatch, develop and are ingested by cattle.  The larvae can survive over winter on the pastures, but are susceptible to desiccation in the hot and dry weather over summer.

A peculiarity with the lifecycle of Ostertagia is that over summer some of the larvae can bury themselves into the stomach wall until the weather conditions become more favourable, usually in autumn, when they emerge in large numbers and cause disease.

While reasonable natural immunity develops with age, we still see some clinical problems in adult cattle and the majority of trials have shown a positive production response to treatment of milkers around calving or drying off.

The majority of clinical problems are seen in young stock.

The clinical signs seen with infestation are a scour, weight loss and in severe infections, bottle jaw and death.  Sub clinically, parasitism shows up as poor growth rates.

 

Lungworm

The eggs of the lungworm also can survive the winter conditions on pasture and will cause disease in young stock in spring.  Coughing, and poor growth rates are the usual signs of lungworm infestation.

Good immunity develops to this particular worm, and lungworm is almost exclusively a problem in young stock.

 

Worm egg counts

Faecal egg counting is an effective and underutilised tool in worm control of young dairy cattle.  Monitoring faecal egg counts enables us to measure the effectiveness of drenching and other worm control measures and enables us to determine if another drench is needed.

In many situations, calves are routinely drenched every 4 to 8 weeks.  While this ensures that worms are not causing any production losses it is costly and increases the risk of developing worm resistance to the drenches.

Monitoring is a simple and inexpensive procedure and involves collection of a small sample from the faeces of 10 calves.  It becomes less reliable in calves over 12 months of age.

 

Drench Types

Mectins (macrocyclic lactones) e.g. Vetmec, Ivomec, Cydectin: Very effective against inhibited larvae and have residual effect and are available as an injectable and pour on.  Best drenches for strategic summer drench and usually best if lungworm present.

Benzimadazole (white drenches) e.g.  Panacur.  Variable effect against inhibited larvae. Mostly oral drench.  Suitable for treatment of calves.

Levamisole (clear drenches) e.g. Nilverm.  Not effective against inhibited larvae.  Suitable for calves.

Not all drenches are suitable for use in milking cows and some are not recommended for use in young calves. 

 

Always read the label to ensure that the product is safe and suitable for the animals you are treating.

 

Worm Control

The provision of safe pastures allows calves to grow with minimal production loss and allows some exposure to develop natural immunity.  This is often very difficult in dairy operations where other factors such as Johnes disease control, limit the area available to young stock.

Drenching with a registered anthelmintic will nearly always be required.

The frequency and type of drench required will need to be finetuned for each farm situation however a basic program for June calving cattle is as follows:

Sept/Oct :  Drench calves.

Sept to Jan: May need extra drenches for calves in contaminated situations.

Jan/Feb: Strategic summer drench, all young stock and bulls.

Apr/May: Drench yearlings and bulls, 2-3 weeks after autumn break.

June/July: May need drenches in yearlings in contaminated situation.

 

At drying off or calving: Consider drenching milkers.

 

In heavily contaminated situations extra drenches will be required especially for calves under 12 months of age.

 

Drenching Adult Dairy Cows.

A review of the literature shows that around 75% of trials conducted on drenching adult dairy cows show a positive response.  Most trials involved drenching cows at drying off or at calving.  The response is usually seen as an increase in production especially in the first half of the lactation and occasionally a slight improvement in reproductive performance. 

The milk response is in the order of 0.5-1 litres per day.

 

Summary

  • Worms are still a significant cause of production loss in young stock
  • Production responses to drenching have also been shown in milkers
  • Effective control programs involve pasture management and efficient drench use.
  • Worm control in young stock can be monitored using faecal egg counts.

 

Call in to TVG for advice on the range of Vetmec products. You will be surprised at our competitive pricing.


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Time Management

Improving time management on a dairy farm enables better control over the business in addition to the obvious benefits of improved productivity and reduced waste and frustration.

The People in Dairy program has simple time management tips for dairy farmers.

Program leader, Dr Pauline Brightling, said it’s very easy to become time-pressed by the daily demands of dairy farming.

“It’s not hard to turn that around by taking a little time to think ahead about what needs to be done, who is going to do it and when it needs to be done by,” she said.

“Planning ahead helps you prioritise the more important tasks so that they get done first and time isn’t wasted on unimportant tasks.
Having confidence that the important tasks will get done in time reduces stress and creates a calmer, more controlled environment for everyone involved.

The People in Dairy website has a series of practical tips from farmers who manage their time well. Their ideas include preparing seasonal calendars, using a wall planner, using technology such as mobile phones, SMS messages for reminders and identifying tasks that could be done by someone else, for example time-consuming jobs that prevent other jobs getting done.


For more information contact The People in Dairy visit www.thepeopleindairy.org.au <http://www.thepeopleindairy.org.au/>  or phone ph (03) 9620 7283.
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Piliguard - Start planning for pinkeye now

This exciting vaccine has greatly assisted farmers to cope with the annoying problem that is pinkeye. It increases an animal’s natural immunity to Morexella bovis; the bacteria that cause pink eye. It is designed to reduce the incidence and severity of the disease.

The vaccine comes in a 50-dose pack; it is administered by a single dose 2ml injection. It is recommended to give the injection under the skin in the neck. It can be administered at the same time as 7 in 1 provided they are given on opposite sides of the neck. The vaccine comes with a specific vaccinating gun that replaces air into the non-collapsible container. TVG can provide these guns and if stored correctly they can be used year after year.

The recommendation is to vaccinate all at risk animals greater than one week of age, 3-6 weeks prior to the expected onset of the pinkeye season, ie from October onwards.

It is important to note that we may still see pink eye in vaccinated animals. We should see significantly fewer cases and that the disease would be less severe.

To adequately control pinkeye it is important to address the factors that propagate the disease, these may include:

·         Using fly control such as Arrest Easy Dose

·         Minimising yarding of at risk stock by performing routine procedures (vaccinating and drenching) before the spread period

·         Minimising exposure of at risk animals to dusty environments

Who should use the vaccine?

·         Anyone intending to sell heifers for export

·         Properties that have had a history of pink eye

·         Properties who send heifers out on agistment or to out paddocks where regular checking of heifers is difficult

We would urge you to begin vaccinating ASAP to create immunity before you expect to see pink eye.

For more information or to order vaccine contact TVG. 55586666


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Getting the most from pregnancy testing

Pregnancy testing, like herd testing is an onerous task, however, technology has made the job easier.  From the vet’s point of view, we have the opportunity to ultrasound herds, which is easier on vets and cows.  Ageing pregnancies with the ultrasound can only be done with accuracy on cows less than 15 weeks in calf.  Any cows further in calf or that cannot be detected with the ultrasound are best done manually to get the most accurate diagnosis.

Given the effort that is required to pregnancy test, it is worth making sure that we utilise all our resources to make the most use of the information.  To do this, here are a few tips:

·         Attempt to have all cow numbers readily identifiable at cow side.

·         Match up NLIS tags accurately with other cow ID for herds that use scanners.

·         Update all breeding records that are available and forward them to TVG to produce expected weeks in calf lists for use on the day of pregnancy testing.  If these are recorded at a herd test centre we can down load them.

·         Organise to do the first pregnancy test between 14 and 16 weeks after mating start date. This means that most herds will need to do a second pregnancy test to recheck empty cows 7-8 weeks after bulls are out.

We are prepared to fit in with your routine for pregnancy testing.  Many herds now choose to pregnancy test during AM or PM milkings.  This is easy for rotary herds. Herringbones can use trolleys in the pit rather than planks if there is not an AI race at the exit. We will provide enough vets so that the job is done as efficiently as possible.  We do have some peak times for pregnancy testing where it may be difficult to book in herds and prepare records at short notice.


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Cell Count Control

Key Facts:

Elevated Bulk Milk Cell Count (BMCC) results in reduced milk income. Reducing BMCC involves implementing good practice in many management areas. Many of these practices involve changes in management, which cost little or nothing!

What can we offer?

TVG now offers three programs designed to help control cell count at the three critical points in the lactation cycle.

o  DRYING OFF. Is not just about which dry cow product to use.  A well planned drying off strategy will set cows up for the next lactation.

o  CALVING.  Smart management of calving cows will make life easier for everyone on the farm and result in reduced cell counts for the entire lactation

o  LACTATION. This is a great time for you and your staff to optimise milking management, including   machine function.

TVG has some vets with considerable experience dealing with mastitis.  We are extremely confident that each of these programs will be well worth your investment.

 

“If your BMCC spends any time out of premium, you can’t afford not to give this a go!”


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