Heat Turned Up on Sheep Selection

Mount Linton's new sheep genetics manager is turning up the heat on

selection for animals that can perform under pressure.

Hamish Bielski took on the role of sheep genetics manager at Mount Linton in April this year and is enjoying the challenge involved in continuing the

breeding program at Mount Linton for Texel and Texel x Suffolk (Suftex)

sheep.

Comprising of two properties and 100,000 stock units, Mount Linton is one of the largest privately owned Stations in New Zealand. It's scale and

determination to be a leader in genetics are key advantages. Mount Linton's

main income base is sheep with lamb being a major earner. While Romneys are the main sheep breed farmed by Mount Linton Limited, the company also farms Texels and since the introduction of that breed in 1990, it now has about 26,000 Texel X Romney animals on its books.

Mount Linton has a strong commercial focus and today it is selling its

genetics throughout New Zealand. The company's breeding objective is stated as striving "to maximise returns through increased meat and wool growth without compromising fertility and survival."

Hamish is responsible for running the sheep genetic property operating

adjacent to the station. He believes the strength of the Mount Linton stock

is their ability to grow fast and yield well in a difficult environment.

After experiencing his first Southland winter this year he is aware the

farming environment is often far from perfect. Another factor farmers are

increasingly aware of is the need for selecting stock that perform under

pressure from internal parasites.

"Parasite burdens on pasture can be a huge constraint so we are putting a

lot of selection pressure on both male and female sheep to come out with

both resistant and resilient animals," he says.

For the majority of ewe and ram hoggets on Mount Linton their last drench is in late winter/early spring and some do not even need this. Ewe hoggets

scanned as twins will be drenched if worm counts are high pre-lamb,

otherwise it is just one drench at weaning. No sheep from the age of 15 months will be drenched.

"As a breeder I believe at times we may face production losses, but

it is my duty to the farmer to do the hard work before the rams leave the

gate," Hamish says.

Faecal egg counting plays a major role in the selection of animals because

it identifies what is happening inside an animal. But it doesn't stop there,

Hamish Bielski says the ultimate sheep is one with low faecal egg counts and who excretes marbles or pebbles. That is why a dag score is being added to the FEC program to measure the animals’ ability to create dags. A faecal

consistency score (FCS) of 1 means the animal produces marbles (less dags)

and 5 is very runny. Faecal consistency has a heritability of 25% so is

well worth pursuing. Hamish says these sheep are definitely in our flocks,

it is just a matter of identifying them and with careful selection these

traits can be maximized.

Hamish says that performance recording on SIL measures key production traits like growth rates and fertility, but not constitution or longevity. For

these traits it is up to the farmer and the environment as to how much

pressure is applied. "If they perform here, they can perform anywhere."

He says "We are putting a strong focus on structural soundness and

constitution, which are the foundation of any recorded animals for longevity

and mobility."

According to Hamish, Mount Linton is so confident of the quality of its genetic program that the company is offering a two-year guarantee to farmers for any ram purchased.

Terminal sire genetic improvement in Mount Linton's Texel and Suftex flocks is strengthened by the use of CT scanning in partnership with eye-muscle ultrasound measurements. Mount Linton uses both the Innervision and Innervalue CT to identify potential sires for their breeding program.

Innervalueä identifies sires with the more meat less fat qualities while

Innervalue puts pressure on sires by identifying those that have more meat

in the high value areas such as the loin and leg.

Mount Linton Genetics continues to work closely with Catapult who develop and market DNA tests for specific production traits in sheep. The latest DNA technology to be released is the gene marker for parasite resistance of which Mount Linton has a number of single and double stars in their Texel sires. A high incidence of the MyoMAX gold gene is also present in the flocks.