Friday, 13 April 2018 09:55

PW evolution will make things simpler

Written by 
Wayne Reynolds. Wayne Reynolds.

Picking easy-care cows is about to get a whole lot easier with the first change to the calculation of production worth in 22 years.

The 1996 introduction of an index for dairy cows that monitored performance via breeding worth (BW) and production worth (PW) was ground-breaking and played a key part in dramatically changing the breed composition of that national dairy herd, says LIC shareholder councillor Wayne Reynolds.

But as the industry continues to evolve, it’s crucial the key index measures remain relevant; that’s why Reynolds is endorsing the first change in 22 years to the way production worth (PW) is calculated.

From February 17, somatic cell score (SCS) became the fifth trait in the PW calculation (protein, milk fat, milk volume, and liveweight are the four original traits).

“There’s no doubt more change is on the way for the industry,” Reynolds said.

“With cow numbers peaking we’re going to have to find ways of doing more with the same resource; and with farm ownership structures evolving, we all need to be prepared for that. So the index needs to remain a strong management tool. 

“I’m pleased to see PW evolving at last, because the industry dynamics have changed but until now PW hasn’t.

“With the inclusion of somatic cell count (SCC) in PW, it’ll allow farmers to pick our easy-care cows with more accuracy. Over the long term and across the national herd, I’m sure we’ll see overall profit margins of farmers increase as a result.”

LIC shareholder council members had lobbied for years for a change to the PW equation, said Reynolds, and high on the agenda had been the inclusion of a fertility production value which, along with body condition score, is being researched further.

“I understand the reasons for the delay in the introduction of fertility and body condition score. I feel fertility is of greater economic impact than SCC, but it’s important to get the data and the science right, and it’s clear more time is needed for that so I look forward to seeing where things are at this time next year.”

Reynolds is part of a farmer advisory panel that provides practical genetics advice to New Zealand Animal Evaluation, the DairyNZ subsidiary that oversees BW.

Time to re-calculate

Wayne Reynolds had seen a prototype calculation of the new PW calculation on his herd, meaning he could compare “the old PW to the new PW”.

“I looked at a few cows I knew had higher cell counts to see what effect the change would have. I know one cow in particular that I was putting in my cull list because of repeated high cell counts, and she’s dropped by 40 PW points.

“It’s what I would have expected, and I have to say the bulk of my herd is unaffected. You don’t expect much movement from them (healthy cows); it’s the cows that have persistently high cell counts that will drop and so they should. My overall herd PW is very much the same; it’s just the within-herd rankings that have seen some shuffling around.”

PW was purely used by Reynolds for culling and selling purposes, but it was not necessarily gospel, he said.

“At the moment you pick your low-PW cows, which are essentially your less efficient production cows, and you make some rather crude selection decisions based on cell count, calving date, fertility or when you have to dry them off in autumn.”

“Now that PW incorporates somatic cell, it’s getting closer to being the one measure to cull on; but there will always be things that make cows unsound that PW isn’t aware of, like feet.

“The new PW equation means there’s certainly one less thing to think about, so it’ll make things simpler.”

• Article provided by LIC

More like this

LIC ready for challenges ahead

Herd improvement company LIC says it's well-positioned for the challenges ahead and remains focused on its core purpose - delivering value for farmer shareholders.

Breeding heat-tolerant cows for Africa

LIC is embarking on a ground-breaking project aimed at breeding heat tolerant and disease resistant dairy cows for Sub-Saharan Africa, in collaboration with the global leader in precision breeding, Acceligen, and the Bill & Melinda Gates Foundation.

Scheme to pick high potential 'underdog' bulls

Holstein Friesian NZ, and herd improvement co-operative LIC have launched a joint sire proving scheme that aims to select and prove Holstein Friesian bulls for New Zealand dairy farmers.

Featured

Massey Research Field Day attracts huge interest

More than 200 people turned out on Thursday, November 21 to see what progress has been made on one of NZ's biggest and most comprehensive agriculture research programmes on regenerative agriculture.

Expo set to wow again

Stellar speakers, top-notch trade sites, innovation, technology and connections are all on offer at the 2025 East Coast Farming Expo being once again hosted in Wairoa in February.

A year of global challenges

As a guest of the Italian Trade Association, Rural News Group Machinery Editor Mark Daniel took the opportunity to make an early November dash to Bologna to the 46th EIMA exhibition.

Boost for hort exports

The horticulture sector is a big winner from recent free trade deals sealed with the Gulf states, says Associate Agriculture Minister Nicola Grigg.

National

OSPRI's costly software upgrade

Animal disease management agency OSPRI has announced sweeping governance changes as it seeks to recover from the expensive failure of…

Machinery & Products

BA Pumps expand

Cambridge based BA Pumps & Sprayers, specialists in New Zealand-made spraying equipment, has acquired Tokoroa Engineering’s product range, including the…

Entries open for innovation award

Fieldays and its renowned Innovation Awards are celebrating their 57th year, marking a longstanding tradition in the agricultural calendar, with…

» Latest Print Issues Online

Milking It

Chinese strategy

OPINION: Fonterra may have sold its dairy farms in China but the appetite for collaboration with the country remains strong.

Not fair

OPINION: The Listener's latest piece on winter grazing among Southland dairy farmers leaves much to be desired.

» Connect with Dairy News

» eNewsletter

Subscribe to our weekly newsletter