Wednesday, July 6, 2022

Baffled farmers missing EBV benefit

Many farmers don’t understand estimated breeding values (EBVs) so they are choosing not to use them, Lincoln University animal production lecturer Jon Hickford says.

Hickford was commenting on the preliminary results of a Massey University-Lincoln University survey that revealed only 25% of farmers used EBVs during the past three years.  

He offered his thoughts after Red Oak Angus owner Ric Orr said in The New Zealand Farmers Weekly EBVs did not fairly reflect animal performance in the field and value on the hook (May 13).

Hickford said the use of EBVs was worryingly low, although the figures did explain some of the long tail-end of under-performance that was seen on New Zealand farms.

He said the poor state of affairs needed to be addressed rapidly and was an industry problem, although he didn’t agree entirely with Orr’s assessment.

“EBVs certainly don’t define the perfect cow or sheep. They estimate the genetic potential of that animal for an individual trait.

“They are a tool to assist breeding. They do work, but like any tool they are only as effective as the operator. That is usually where the problem lies.”

Hickford credits the immense improvement in dairy cow production to the use of EBVs. Putting aside recent issues with some single gene faults, there had been a huge increase in per cow milk solid output. That had been worth a lot to NZ dairy farmers and to the economy, he said.

He agreed with Orr’s criticism of “feedlot genetics”. Feedlots were interested only in buying stock with a good genetic potential for growth and at the lowest possible price. They focused on growing that stock to slaughter weight and specification as rapidly as possible.

In comparison he suspected the average hill-country farmers wanted cows that managed pasture effectively and foraged for feed, were fertile, held condition through the winter, calved with ease and weaned their calves at a good weight.

“These are mostly maternal traits and they perhaps don’t receive the prominence they should in breeding. Feedlot genetics also seems to result in larger mature weights and this will increase the maintenance cost of cows at a time that they need to hold condition and sustain a pregnancy,” he said.

He also thinks calf producers need to be better informed about capturing the advantage of hybrid vigour. Pure breeds will be outperformed by crosses of good genetics, so the use of terminal sires for calf production needs to be reinforced.

However, he warned even index-based selection didn’t guarantee perfect genetics. The dairy industry Breeding Worth Index had to be re-engineered to address the declining fertility of dairy cows. 

An index value was merely the sum of a collection of EBVs that had been weighted based on their priority or economic value. 

“Index values do not tell you about individual traits, so any given animal with a high index value may be very poor as regards an important individual production trait.”

Hickford said some breed groups were using genetics well, like the NZ Romney breeders, who run their progeny tests in both islands and have a link sire into the Central Progeny Test (CPT) each year.

“This linkage will improve the genetics and performance of one of our key breeds of sheep.”

Given Orr’s comments about the Angus breed, perhaps breeders should be contemplating a NZ-based progeny test, rather doing their genetic evaluations in Australia, Hickford said.

  • The New Zealand Farmers Weekly invited major breed groups and a prominent Angus marketer to comment on Ric Orr’s assessment. None had gone on record at press time.

Read Jon Hickford’s full comment

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