Articles

Pre-Lamb Ewe Parasite Control

For those of you that subscribe to the AgLetter - I refer you to the excellent article of the 3^rd July issue.  As usual Chris Garland and his team get the “good noise” on issues and present excellent information to the industry.  This article reviewed the practice of using Long Acting (LA) treatments in ewes pre lamb and my comments are as follows (you will need to read the article first).

• Unquestionably correct in context.
• Principles and recommendations entirely correct, in line with those of Wormwise and absolutely endorsed by Vet Services HB.
• Your individual situation is likely to be far removed from that of “ideal”-this season.
• Your level of acceptable “risk” re introduction or enhancement of drench resistance is your business.We can advise but never dictate.
• Whilst Drench Resistance is a huge issue for your individual farming operation, the NZ Sheep Industry and NZ Inc never forget the ubiquitous issue of subclinical parasitism. Both must be on your radar screen - and to swing toward either pole of whole flock treatment or no treatment at all, unwittingly, could well be disastrous.
• The most cost effective (productive) and sustainable decisions are heavily reliant on background relevant information.

Information includes in order of significance:

• Ewe body condition score (BCS) quantified, accurate, drafted
• Pregnancy status (single/twin/triplet) *
• Age *
• Current Nutrition *
• Feed cover at lambing
• Future Nutrition
• Set stocking rate per Ha*
• Ability to alter any of the above
• Parasite burden (FEC + LC to tell which species present)*

[*denotes quantified accurate information available to you post scanning].

As an overview the 2010 year in CHB has been “different” to previous years.  January/February rains gave a huge nutritional boost to all sheep.  Feed covers rose quickly which negated quite a lot of worm intake via the fact that we asked our sheep to eat only the top of the grass and not graze too far down (decrease L3 parasite intake).  Early scanned ewes therefore tupped very very well (= February, early March).  Ongoing dry conditions decreased nutritional intake by less grass (declining covers) and poorer quality feed.  Subsequently we have seen some “disappointing” i.e. lower than last year - scanning results for late March/early April mated ewes.

Currently (July) we are back in a similar position to the last few years but we've got here a different way.  Nutritional, environmental and physiological (pregnancy/nutritional) status “pressure is on”.

The essence of all of this is that if you have

• BCS < 2.5 multiple bearing ewes
• feed covers < 1100 kg DM/Ha
• set stocking rates that will need to be > 7 twinners/Ha
• lambing in August

or to put it another way

• skinny twinners *
• smack a golf ball and be able to see it
• a farm that's too small for winter stocking rate = not enough paddocks

(* if you haven't shorn you need to feel the backbone/ribs of some)

then you just cannot afford to do nothing pre lamb.

So back to where I began. 

Should you treat all your ewes with Long Acting Products NO! 

Should you treat none of your ewes with Long Acting Products  NO!

Is there a happy/economic/sustainable medium YES!! 

There is a wide range of excellent products that fit most situations.  Now is the time to work out/find out what you need.  There is plenty of help available within our business to help gain information to make the “best” decisions.   All you need to do is ask.  If it is a big job then please give us warning and time to do justice to your request.

It is also timely to consider the management of Drench Resistance - especially when considering “the risk” that pre lamb treatment of ewes poses.

Veterinary Services has (probably) conducted as many Faecal Egg Count Reduction Tests (FECRT's) as any area in New Zealand.  “Generally” - our area results are generally very predictable and follow these lines.

• Benzimidazole (white drench) resistance usually present - Nematodirus, Cooperia
• Ivermectin resistance usually present when we use ½ dose test = very sensitive. Again to Nematodirus and Cooperia but also Ostertagia.
• Benzimidazole/Levamizole (dual combination) resistance sometimes present and usually only Trichostrongylus.
• Very Little/No Abamectin, Moxidectin, Triple drench resistance.
• We are continually informed of significant other relevant New Zealand wide information that gives us perspective.

This means

• 1. Drench resistance exists but is not “rampant” or unmanageable.
• 2. We can manage it on every farm where we know it's present. And we can do this without yet utilizing new actives (Zolvix/Startect)
• 3. Where integrated grazing systems, better nutritional inputs and resilient/resistant animal genetics are used we can manage it even better.
• 4. Where we choose to use new actives we will manage it even better still (albeit costing more) and elongate the effective life of existing drenches.

So all is not lost!!

Don't despair or see this as the paramount limiting factor to decisions you need to make this month!

Do please

• take this advice/comment in context
• find out your own FECRT status - it's like “not” shooting in the dark
• make informed productive decisions re. potentially large future income - this year!
• find out what fits your situation.

Best wishes for a great lambing and a bountiful spring.