New Zealand agricultural history. No 16. Importing exotic sheep breeds

 

Importation of exotic sheep breeds

Second MAF importation

Quarantine station at Hopuhopu

Veterinary inspection

MAFQual veterinarian Peter Hoyle

 Dr Clive Dalton

Hopuhopu quarantine station

Hamilton MAFQual veterinarian Peter Hoyle’s  memories

 I was new boy on the block and had some experience in quarantine while working in the UK as a state veterinarian. So I got the job nobody else wanted, to provide veterinary supervision of the Hopuhopu quarantine station for the sheep imported from Finland and Denmark as embryos. 

With members of the Ruakura Genetics team, we thrashed out some rules of procedure and structural requirements to ensure a credible disease confinement programme. 
Photo: Peter Hoyle, happily retired in Vanuatu 2014 where there is no sheep.  Local dogs cleaned up the last few!

The Hopuhopu property owned by Tainui was known to be infected with Ovine Johne’s Disease (OJD), and we devised a programme to attempt to clear infection ahead of the imported animals arrival, as we needed to import local sheep onto the station to be embryo recipients during the intensive multiplication phase.   So another programme was devised to try to avoid importing OJD with these Romney recipient ewes.

MAFTech technical officer Ian Malthus, rattling the feed bucket 
to move the sheep at Hopuhopu

The imported purebred exotic breed sheep arrived as weaners from Somes Island and had never been out of doors.  They were accustomed to being hand fed so the easiest way to get them to go places was to walk in front and rattle a bucket. They had never seen a dog before, and the first dog they met got a very thorough physical going over by them - much to the dog’s embarrassment and disgust.

Duties

• My duties involved regular visits for the following jobs: 
• For animal health and examination of sick and dead animals.   
•  For veterinary oversight of the embryo transfers done at the multiplication stage in the Hopuhopu woolshed surgery.
• To advise on routine disease control measures.
• To advise on quarantine procedures.
• In the final stages, to supervise the post mortem examination of the entire original imported purebreds at the Ruakura Abattoir.  Here we found that all our efforts to eliminate OJD had failed, but there was no evidence of Scrapie from examination of brain tissue.

 
Peter Hoyle providing post-operative care to sheep after Embryo Transfer.  21 March 1986.  Photo by Jaap Jasperse, NZ Farmer magazine

I remember one incident when I arrived on the station and found a ewe acting very strangely and making me suspect that it could be Scrapie.  To my relief, I found that she had been overdosed with oestrogen, which explained her odd behavior. Finding scrapie at that stage would have been the mother and father of all disasters!

Alan Julian

With another sick sheep, specialist veterinary pathologist Alain Julian then at the Ruakura Animal Health Lab diagnosed a rare genetic kidney disease (Mesangiocapillary Glomerulonephritis) from samples I submitted taken from a Finn lamb. 

Alan sent sections of the kidney to Dr Dick Barlow in Scotland and they confirmed the disease.  The good news was that it was not Scrapie!  
 
We also had problems with Necrotic Laryngitis in the Texels at Hopuhopu. This can be nasty and lead to death by suffocation.  It is also called 'chronic ovine laryngitis' caused by a bacterium with the monika of 'Fusobacterium necrophorum'. 

Other breeds of sheep can get this too.  Feeding too much dry feed can bring it on - and the sheep were fed plenty of that on the station to keep them growing.


Photos from  Hopuhopu  provided by Mike Wolland, Technical Officer at Hopuhopu

One of the many ammunition bunkers on the Hopuhopu army training area.

Truck washing  after sheep arrived from Soames Island maximum quarantine station

 

Hopuhopu quarantine station needed facilities for handling sheep and wool and doing surgery. 

 

MAF Technicians Graham Hasard (left) and Mike Wolland preparing recipient ewes for embryo transfer.  Photo by Jaap Jasperse of NZ Farmer, 21 March, 1986.

 

Operating on embryo recipients in Hophopu woolshed surgery.  Photo by Jaap Jasperse of NZ Farmer, 21 March, 1986.

 

Mike Wolland and Texel ram at Hopuhopu quarantine station

 Farmer reactions to the Texels

But my most telling memory was the reaction of  visiting sheep farmers, in particular the Perendale breeders when the saw the Texels for the first time. In no time they were queuing up to put their names down to purchase some when quarantine was finalised. They probably recognised the Cheviot in the Texel which was also part of the Perendale too, so thought there would be good ‘nicking’ among the genes of the two breeds.

Quality Texel rams that every farmer wanted, especially Perendale breeders.

New Zealand agricultural history. No 20. Importing exotic sheep breeds

Facial Eczema at Hopuhopu

Quarantine at Hopuhopu

Implications for sales 

By Dr Clive Dalton

Facial Eczema at Hopuhopu

The mixed breeds of hoggets at Hopuhopu quarantine station. 
The Texels were most prone to Facial Eczema

When the time got near to release the sheep from quarantine in 1990, news had spread that the Texels at Hopuhopu had been badly affected by Facial Eczema, and there was considerable internal debate about what to do about this.   First, there was the concern of shareholders accepting affected sheep, and secondly concern over them having to sell liver-damaged sheep to their clients. It was all about 'marketing ethics', and many MAF technical staff at Hopuhopu who had to work and treat the sheep were very concerned.

However looking back, and trying to get the full story now,  it seems as if the marketing gurus were happy to leave things in a state of  ‘buyer beware’. There could have been some nasty legal implications of course, but if there were, nobody can remember now.

The Waikato has always been a 'hot spot' for FE and it has a devastating effect on sheep, both externally (see photo), but more so in liver damage preventing the fungal toxin from being excreted. 
 
Photo shows some badly affected Perendale ram hoggets with FE showing skin lesions on face and ears. These sheep did not survive, even after treatment, as their livers were too badly damaged.

The breed was clearly too valuable for the Company to be over concerned about the effects that FE may have had on individual rams.  This lack of declaring the presence of FE in some sale rams really bothered the professional ethics of some MAF staff, and apparently some nasty internal memos floated around.

John Dobbie

John Dobbie of the Ruakura Genetics section told me of his concern after finding clear FE signs on the Texels when wool sampling at Hopuhopu, and putting it in a report to Ruakura Research Station Director Ken Jury, who called him to his office at 5pm one day for what John described as a real bollocking. 

John, being John, would not accept Ken’s reprimand and told him straight, as the facts were the facts.   Staff member Ian Malthus says he was ‘moved on’ to another MAF research job as a result of his ethical concerns, about offering rams for sale that were known to have had FE.  He openly voiced his concerns and he got the clear impression that he was speaking out of turn and the marketers didn't like it.

All the purebred Texel rams and ewes were sold from Hopuhopu and Robin Hilson remembers that Mount Linton took over the 180 unsold Texel crosses.  Robin says that as they had not been well managed, he had to hang on to them till the autumn as they were unsalable in the spring. He bought at least 150 younger Texel crossbreds and sold them on eventually.

In my view, the most likely reason for the poor Texel performance at Mount Linton was that they would all have had sub-clinical FE, and have compromised livers which would have taken a very long time to recover.  It’s now well accepted that affected livers never fully recover.

Peter Hoyle

MAF veterinarian Peter Hoyle who was responsible for regular visits and supervision of animal health at Hopuhopu remembers the FE outbreak well, and how the old ammunition bunkers on the property (which had been a WWII firing range) came into their own to keep sheep out of the sun during the day,  allowing them to feed at night. So there was plenty of evidence of clinical FE in the Texels.

FE and Finns
Everyone was surprised, and no doubt relieved, that the Finns didn't go down with FE like the Texels, and there was a fair bit of conjecture as to why.  Some came up with the theory that they must have genetically developed high immunity to pasture toxins over generations, although there was no FE disease in Finland. 

The Finn FE tolerance grew with the telling, and became a big marketing feature for farmers in FE prone areas.  Coopworth breeder Edward Dinger who has selected for FE resistance on the MAF Ramguard programme for 30 years, where rams are dosed with the FE toxin (sproridesmin), and who was in a small group that purchased 45 pure Finn rams at $1000 each, says that the Finn has 'useful but low FE tolerance to a level of 0.3mg sporidesmin/kg of liveweight'.

Dinger Coopworths and other Waikato breeders are dosing rams at 0.6 mg sporedesmin/kg live weight now, and have eliminated the effects of the disease, even in the most severe outbreaks.