Friday, March 29, 2024

Selection the test

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FE Gold represents some breeders who have been tolerance testing for facial eczema (FE) over many years and are now testing at the highest possible dose rate of 0.6mg/kg. This is where the animal is dosed with the toxin and blood tests assessing liver damage measures how tolerant the ram is to the FE-causing toxin.
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Perendale breeder Russell Proffit chairs FE Gold. While his stud has been testing for FE tolerance for 15 years they are not yet testing at a level where they can claim fully-fledged FE Gold status.

Romney and Coopworth breeders have been at the forefront of testing and selection for FE tolerance but any breed can join provided they meet the testing criteria.

One aim of the group is to educate farmers about the disease and get them to ask their breeders the right questions when it comes to selecting rams that are tolerant to the production-limiting disease.

Proffit said farmers need to be aware of the length of time it takes to breed tolerance into the flock. Buying an FE-tolerant ram one year will not mean a FE-tolerant flock the next.

When selecting rams he urges commercial farmers who want to include FE tolerance in their trait selection to ask the breeder how long they have been testing rams, the level they are testing at, the number of rams they test every year and ask to see the RamGuard certificates.

RamGuard is the AgResearch-managed organisation that carries out the FE tolerance testing.

Proffit said farmers serious about breeding for FE tolerance should aim to test four to five offspring by each sire and only use tested rams in their stud.

It can take 20 years to breed to a high degree of FE tolerance. Breeders start at zero, gradually building up to an optimum dose rate of 0.6mg/kg.

Commercial farmers can breed FE tolerance into their flocks much faster by selecting rams from FE Gold flocks.

These rams may command a premium – reflecting the huge amount of time and money invested in breeding for tolerance – but long term will reduce costs and losses related to facial eczema, Proffit said.

He said it is frustrating to hear rams being advertised as having been tested when they are just the progeny of FE-tested rams. 

Simply not having seen FE in a flock does not mean the animals are genetically tolerant to the disease.

FE-tested rams

If in doubt about FE-tested rams, commercial farmers should seek independent advice or go to the SIL website at www.sil.co.nz for the up-to-date RamGuard list. More than 30 ram breeders are registered on the RamGuard list as testing for FE tolerance.

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