Pre Lamb Treatments for Ewes

Pre Lamb Treatments for Ewes

Pre Lamb Treatments for Ewes……..

There are not many times of the year that you can influence the production from your sheep flock. One notable time is pre-tupping through ram/ewe selection, and mineral and vaccine choices designed to maximise the conception rates. The other is pre-lambing.

This critical time when the ewe‟s natural immunity relaxes (Peri-parturiant relaxation) and her ability to cope with a parasite challenge is reduced. Choices you make then can have an influence on lamb weights at weaning and ewe weights prior to the next tupping period.

If we assume your feeding is as good as you can make it, ewe treatments pre -lamb come down to a choice of

1. vaccines

  1. anthelmintic treatments
  2. mineral supplements

Vaccines:

Clostridial Vaccines:

At around 30 cents a dose, clostridial vaccination is an inexpensive
insurance. You will be protecting the ewe during a period of susceptibility and the lamb via the ewes colostrum for around 8 weeks. The loss of only one lamb or ewe pays for a lot of protection at today’s pricing. 5 in 1 vaccine does not cover all clostridial cases so consider ULTRAVAC 6 in 1 for a little more protection. 6 in 1 vaccine includes Clostridium sordellii which caused ‘Sudden Death Syndrome’, more recently recognised in NZ.

Pre Lamb Ewe Treatments .. The options ..

Vaccine Suggestions:

  • Sheep are very susceptible to Clostridial diseases so vaccination to prevent them is an inexpensive, but essential pre-lamb activity.
  • Vaccinating the ewes 3 to 4 weeks prior to lambing will provide a good level of protection to the lamb via the colostrum for about 8 weeks. It will also provide long term (1 yr) protection to the ewe.
  • If ewes have NOT been vaccinated before. they should have a “sensitiser‟ at least a month before their pre-lamb “booster‟, which should be timed for 3 to 4 weeks before lambing.
  • Lambs are most susceptible to Pulpy Kidney especially during periods of feed change. Of the clostridial diseases this is the one that a lesser immunity may be only be achieved. You should therefore consider a booster for the lambs at tailing time or at about 8 weeks of age (PK/Anti-tet, if available or an un-selenised 5 in 1) to provide further protection after 8 weeks through to weaning.
  • The strongest and longest vaccine cover is provided with “Nilvax‟ which also includes the anthelmintic, Levamisole. This can be useful as a ‘primer’ dose prior to administering capsules.

• Change needles frequently. Administer under skin behind ear. Store vaccines at fridge temperature at all times.

Other vaccine options available include 5 in 1 vaccines with either or both B12 and Selenium. (see below)

Anthelmintic Treatments:

Oral liquid treatments are probably of very limited value unless your ewes are suffering from a high worm burden throughout the winter. This is unlikely if they are being well fed and being kept in good condition with no other concurrent disease e.g. Johnnes or liver fluke. If you are going to use an oral drench, then a dual or triple action product (Matrix or Switch) should be used.

No treatments (yarding of ewes) to ewes should be given in the last two weeks of gestation, due to the risk of stress related abortion, so the short action of an oral anthelmintic will miss that period of immune suppression or “pre-parturient rise‟ immediately prior to lambing, making them of no value to the lamb and of little value to the ewe.

Injectable anthelmintics may give a benefit as a pre-lamb ewe treatment but to be clear, they do not compare with drench capsule technology and they may pose a
risk to resistance development through the effect of their “tail‟ of
anthelmintic levels in the ewe below therapeutic levels.

Advertising tries to compare a Moxidectin LA (Exodus or
Cydectin) treatment with capsules and gives the impression that they are equally effective for 100 days. This is only true for one parasite, Ostertagia, which is not generally significant in sheep. More significant is the parasite Trichostrongylus against which Moxidectin is effective for a maximum of 42 days. All the rest, and some are very significant such as Nemotidirus, efficacy is for only 1 day! This is pretty much of no use at all, because the benefit will have passed long before lambing and the period of ewe immunity suppression.

In summary only Moxidectin LA will give some sustained benefit; all other injectables such as Eweguard and abamectin (Genesis) injectable will be of questionable benefit to ewe and lamb and can definitely NOT be compared to capsule technology. The main reason for this is the “constant contact‟ of the anthelmintic in the capsule, minimising the effect of the lowered immune response and energy diversion. What this means is the ewe can utilise every blade of grass into either milk production or body condition.

The advantage of injectable anthelmintics is a lower cost per head and ease of application. I addition the likes of Eweguard and Nilvax, they are combined with a 5 in 1 vaccine.

Anthelmintic or Drench Capsules vary in the active ingredient they carry, but all will last for 100 days at therapeutic levels.

If you have parasite resistance issues you need to be aware of your status and select a treatment that you are confident will work. If you are uncertain, then you are safer with a combination product. A premium capsule with combination anthelmintics is BIONIC and this will provide therapeutic levels against all 13 internal sheep parasites for 100 days.

To achieve a production gain (assuming your feeding levels are good) the requirement is to have an anthelmintic in the ewe at lambing time and for a reasonable period after lambing. In the face of a parasite challenge, the ewes energy will not be diverted to the challenge on its immune system, but will be put into maintaining its condition and milk production for lamb growth. The net result is a significant increase in lamb growth (supported by numerous trials) which is the real benefit of using capsules over other treatments and it is what sets them apart from all others.

Capsules provide many benefits:

  1. Increased ewe milk production resulting in better lamb weights at weaning

    (between 4 and 8 kg)

  2. Better ewe weights at weaning (average 5.8kg)
  3. More lambs away at first draft
  4. Increased wool production.
  5. Ewes in better condition at mating (= more fertility)
  6. Less dagging

Yes, they do cost more per head, but numerous trials over the years have shown that with good available feed, production gains as mentioned above will produce an economic return on the cost of the capsule.

In the interests of ‘refugia’ and on the basis of return on outlay, you might consider just treating the more susceptible ewe groups. This would include twins and triplets, hoggets (if mated) and 2-tooths.

In Summary:

  • Drench Capsules are the only product that has been proven to be an “Investment” i.e. “you get a return on your money spent”. (Numerous trials show heavier lambs and most important, heavier ewes going back to the ram after weaning. Often your weaning weights become your tupping weights … this then effects next years lamb crop). In fact all things being equal e.g. feed supply, capsule ewes “stand out‟ in their body condition, milk production, lamb growth and post weaning ewe weights !
  • Other treatments (injection and oral) may be cheaper but; they are only a treatment for the ewe with comparatively minimal long term financial benefit.
  • You need to know your farms resistance status.
  • Trich sp worms are the main worm of concern in Tasman. NOTE: Be careful

    of adverts that say injections last for 100 days. They do, but for only one

    relatively insignificant parasite in ewes !

  • If stock are light, use pre-lamb treatments earlier (4 to 6 weeks pre-lamb)

    compared to ewes in good condition (2 to 3 weeks out).

  • Use a primer drench with Extender SeCo Capsules at the time of capsule

    dosing. (suggest Nilvax or Levimisole Oral or Matrix)

Minerals.

  • Vaccinations give you the opportunity to provide selenium and cobalt (B12) which will raise levels for 4 to 6 weeks.
  • Oral anthelmintics will only provide very short term mineral supplementation, and injectable anthelmintics may contain selenium and cobalt (B12), also lasting 4 to 6 weeks.
  • Drench capsules (BIONIC, EXTENDER SeCo) provide cobalt and selenium by slow release for 100 days.

Additional minerals can be of benefit for lamb survival and there is research to support this. Of note is LSD, originally developed by Vet, Pete Anderson of Blenheim.

Mineral Supplement Suggestions:

  • Most common minerals required by ewes and lambs include: Selenium, Vitamin E, Iodine, Cobalt, Zinc, Chromium and in some cases copper.
  • You tend to pay for what you get. If it is cheap, it will either have very low levels of some elements or they will be a largely unavailable form.
  • LSD is the “Gold Standard‟ and has been well researched. Others with fewer ingredients may be sufficient.
  • Avoid giving two Selenium products at one time due to potential toxicity. Repeated fertiliser applications of Selenium may negate the need to give further supplements. (Exception: LSD can be used with one other form).
  • It always pays to run biannual optigrows of stock classes to know your farm levels of key minerals. (Selenium, Copper and Cobalt).

The Vet Centre, Richmond & Motueka.

Gladstone Road, P.O.Box 3509, Richmond, Nelson.

Phone: 03 5445566 Fax: 03 5445561

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