April 23, 2014

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.

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