Thursday, 14 May 2015 16:41

Aim for tight BCS spread at calving

Written by 
The cows at greatest risk of poor reproductive performance are the first and second calvers. The cows at greatest risk of poor reproductive performance are the first and second calvers.

Range in body condition score (BCS) is as important as average BCS at calving, says DairyNZ.

The ideal BCS of 5.0 for mixed age cows and 5.5 for first and second calvers is a target for each individual animal, as well as a herd target.

The cows at greatest risk of poor reproductive performance are the first and second calvers. 

“We all know that within a herd there is always going to be a range of BCS, as each animal will have a slightly different metabolism, intake, milk production, etc,” it says.

The challenge is to get the spread in BCS at calving as small as possible around the targets. Aim for at least 90% of mixed age cows being BCS 4.5-5.5 at calving.

There are various strategies managers can use to get every cow close to her ideal BCS at calving within a herd, such as:

Drying-off low producing, fat cows early
These cows put fat on their back instead of milk in your vat. When feed is short, herd milk production commonly increases by drying-off the low producing fat cows as the other more productive cows are fed better. And there is often an area of low quality feed on a farm where these cows can be put to maintain themselves, such as steep sidelings or gullies.

Ensure heifers are on track for weight and BCS
Check every four-six weeks that replacements are gaining enough weight and remedy any shortcomings. Aim to have these at BCS 5.5 when they return from grazing, as they will put on little weight (and often lose weight) while they adapt to being in the herd. Well grown heifers introduced to the mixed age cows during the dry period will compete well as milkers.

Give the first calvers more time dry than older cows
Young cows are still growing to reach their mature weight and often have lower intakes. Therefore, they are only able to put weight on slowly, and require more time to get to target condition.

Split dry herds on BCS and time until calving
If you dry-off all at once then it is necessary to split the dry cows into herds based on condition and expected calving date. This allows for preferential feeding to get all cows to target BCS. Even if not enough feed is available to put on extra condition, creating herds is still a good idea, as it protects the younger cows from competition from the older more dominant cows. If supplement is going to be fed then feed it to the herd you want to gain the most condition or that needs to put it on fastest.

Staggered dry-off based on BCS and time to calving
The principle here is that every dry cow can be fed the same, but the difference is how long she is dry for. In low input systems, the dry-off decision rules work well. In higher input systems, where dry cows are well fed on a mixture of pasture and supplement, cows at BCS 4.5 or better only require 50-60 days dry; cows at BCS 4.0 or worse need 80-90 days dry.

Part season once-a-day (OAD) milking for all or part of the herd
Cows that are milked OAD are less likely to milk off their back than cows milked twice-a-day, and when well fed will put more weight on during lactation. Groups of cows particularly vulnerable to not reaching BCS targets, such as first calvers and early calving cows, are ideal candidates for part-season OAD milking.

The key is to go on OAD early enough to have an impact on BCS, as milking OAD for a couple of weeks or a month before drying-off has little impact. The reduction in daily milksolids production can largely be made up by milking on for longer, as cows do not have to be dried off as early due to BCS. OAD milking is unwise where the herd already has a high SCC, as it will increase when starting OAD.

More like this

Musical chairs

OPINION: DairyNZ's director elections has seen scientist Jacqueline Rowarth re-elected for another three-year term.

DairyNZ levy to increase?

Retiring chair Jim van der Poel has used his final AGM to announce the intention to increase the DairyNZ farmer levy for the first time in the industry-good body's 17-year history.

Tributes to retiring 'Jim the farmer'

Doing what is right, not what is easy, has been the hallmark of Jim van der Poel's leadership of, and advocacy for, the dairy industry, attendees at the DairyNZ annual general meeting heard last week.

Featured

New ag degrees at Massey

Changing skill demands and new job opportunities in the primary sector have prompted Massey University to create a new degree course and add a significant major into another in 2025.

The show is on!

It was bringing in a new Canterbury A&P Association (CAPA) show board, more in tune with the CAPA general committee, that has ensured that Christchurch will have a show this year, says CAPA general committee president Bryce Murray.

National

'Quite a journey'

Former Synlait chief executive Grant Watson says the past two years have been quite the journey.

DairyNZ levy to increase?

Retiring chair Jim van der Poel has used his final AGM to announce the intention to increase the DairyNZ farmer…

Former Fonterra CEO dies

Former Fonterra chief executive Theo Spierings passed away in the Netherlands over the weekend.

Machinery & Products

Milk Sustainability Centre launched

The recently announced Milk Sustainability Centre – a collaboration between global giant John Deere and milking and feed specialists De…

Data connection made easier

New Holland and Case IH are introducing new advancements in their precision technology stack to make farming easier and more…

» Latest Print Issues Online

Milking It

Feed from farmers

OPINION: The country's dairy farmers will now also have a hand in providing free lunch for schools.

Brighter future

OPINION: The abrupt departure of Synlait chief executive Grant Watson could be a sign that Chinese company Bright Dairy, the…

» Connect with Dairy News

» eNewsletter

Subscribe to our weekly newsletter