Is it time to do away with days to calving EBVs?

Days to calving EBV data not feeding through to Breedplan


Beef
File photo of Limousin females.

File photo of Limousin females.

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The figures for Limousin submissions shocked producers.

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ONLY 77 Limousin submissions for the days to calving estimated breeding value have been supplied to Breedplan in the past five years, with many producers unaware of shortfalls in their applications.

The lack of data has resulted in the trait being turned off for the Limousin breed, despite being one of the primary Breedplan fertility assessment tools.

Speaking at the Limousin Society's two-day conference in Armidale last week, Southern Beef Technology Services technical officer Boyd Gudex said submissions for the trait were low across the industry after changes were made in 2012 around the way it was recorded using fate codes.

In order for days to calving to be analysed producers must submit the joining details of naturally mated females, information on females removed from the herd and all birth dates of their calves.

When producers register their calves with their society they submit their birth dates and joining dates but many were surprised to learn that information was wasted.

Mr Gudex said Breedplan had different fate/disposal code information to breed societies which was used to differentiate between penalising females who were culled for infertility and those that were culled for other reasons like structure.

Southern Beef Technology Services technical officer Boyd Gudex speaks at the Capitalise on Carcase conference.

Southern Beef Technology Services technical officer Boyd Gudex speaks at the Capitalise on Carcase conference.

"Up north they were reporting about 13 per cent of all registered animals had their dams recorded for days to calving," Mr Gudex said.

"When they made that change they dropped from three to four per cent, the same thing happened in southern Australia. The difference was after about three years the north figured it out and have gone back up to where they were.

"We are still cruising only three to four per cent recording days to calving. We have identified it's a priority, we need to get telling people what's going on."

Limousin performance recording trends.

Limousin performance recording trends.

Australian Limousin Breeders Society president Mick O'Sullivan had been recording Breedplan data for a long time and said it was the first he had heard of the changes.

"Shouldn't we be working with ABRI (Agricultural Business Research Institute) and Breedplan to get permission for the data you want?" he said.

"You are always going to have trouble if you are wanting producers to submit the same information twice."

Is it time for a new fertility EBV?

Dr Doug Fowler of the Australian Livestock Scanning Services Group believes it's time to replace the days to calving trait with a more accurate form of measuring fertility.

Dr Doug Fowler of the Australian Livestock Scanning Services Group.

Dr Doug Fowler of the Australian Livestock Scanning Services Group.

Days to conception would instead measure the period from when the bull was in until mating occurred and had been successfully measured during a trial at Arthur Cox's Speriby North property.

Dr Fowler pregnancy tested and foetal aged a herd of Angus heifers and was able to predict the days to conception with a high degree of accuracy.

He said the current days to calving EBV was easily influenced by factors not related specifically to fertility.

"Cows don't always wait 21 days for the next cycle," he said.

"Variation in gestational length have nothing to do with cows getting pregnant and they detract from the days to calving EBV as a fertility index.

"Progress for any trait through selection is more effective when it is direct rather than indirect so the question is why is there not an EBV for days to conception?"

"Days to conception can be estimated with a high degree of accuracy, it can be done at commercial rates of throughput. We have scanned up to 400 head a day and it can be done at pregnancy scanning time with comparison to days to calving which requires observation of a calving herd."

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