Taking the 6 Week Challenge will help you put a focus on your herd's reproductive performance

Improving your 6 week in-calf rate will provide a range of benefits to you and your farm’s profitability.

The industry target is to get 78% of your herd in-calf in the first six weeks of mating. Are you up for the challenge?

We believe, for most dairy farmers, a year-round approach to increasing your 6 week in-calf rate is the best thing you can do to boost your farm’s productivity and profitability - and the 6 Week Challenge can help you do that.

The 6 Week Challenge was developed to support the DairyNZ InCalf programme, after research identified reproductive performance to be one of a farmer’s top concerns, and an area they wanted more help with.

It provides dairy farmers with the tools and information they need, to make their herd’s fertility a focus all year-round and get more cows in-calf quicker at mating time. 

Any advice, tasks or suggestions given on this website (“advice”) are of a general nature only and may not be suitable for your individual herd requirements.  We recommend that you discuss your individual herd requirements with your veterinary and farm advisory professionals.  Any results from the advice given on this website may vary and LIC gives no warranty that the intended outcome will be achieved.

Ready to take the challenge? Sign up now


Your 6-week in-calf rate is the number one measure of your herd's reproductive performance

It’s all about the single most important figure for measuring your herd’s reproductive performance on farm - 6 week in-calf rate

6 week in-calf rate = the percentage of the herd that gets in-calf during the first six weeks of mating

Your herd's 6 week in-calf rate is one of the most powerful indicators of how well your farm is operating.

Much more than a basic measure of fertility, it also delivers:
      •   more days in milk in early lactation
      •   more AB replacements (to keep or sell)
      •   fewer empties (less wastage); AND
      •   more choices to build the herd you want.

The average 6 week in-calf rate on New Zealand dairy farms is currently 65%, below the industry target of 78%, and this gap represents a significant opportunity for many farmers - an estimated $28,000 for a 400-cow dairy farm! See our STATS & FACTS

Closing the gap won’t happen overnight, but now’s a great time to get started – and the 6 Week Challenge can help you do that.

Is this the most important number you can measure?

While the empty rate is a measure of the final outcome for a mating period, the 6 week in-calf rate measures performance during the all-important first two rounds of mating.

Research has found that cows which calve in the first 6 weeks will get back in-calf quicker than cows which calve in the second 6 weeks, so it's all about achieving sustainable herd fertility too.

Ask any farmer with a high 6 week in-calf rate and they’ll tell you how it makes their life easier, their job more enjoyable and the farm more prosperous.

Ready to take the challenge?  Sign up now


 Give your cows the best chance to stay in the race

Getting cows in-calf quickly so they calve down quickly is a foundation principle of seasonal dairy farming.

For cows, it’s like a race against time, with 282 days of the year spent being pregnant, they only have 83 days between calving and mating.

Earlier calving leads to earlier recovery, cycling, and more chances to conceive - which means more cows in-calf earlier.

Race Against Time

Getting cows in-calf early takes a year-round approach

Genetics certainly play a role in cow fertility, but it is the herd management practices all-year round which have the biggest impact. It takes a whole-farm approach to effectively manage your herd’s reproductive performance and increase your 6 week in-calf rate.

Careful management all year-round will set your cows up for success and provide sustainable fertility improvements that will give them the best possible chance of getting in-calf sooner at mating time, year after year.

The 6 Week Challenge will help you to apply a whole-farm, all-year round, approach to managing herd reproductive performance, and focus on the eight key management areas that affect herd reproductive performance:

     1.   Calving pattern
     2.   Heifer management
     3.   Body condition and nutrition
     4.   Heat detection
     5.   Dealing with non-cyclers
     6.   Genetics and artificial breeding practices
     7.   Bull management
     8.   Cow health

Ready to take the challenge?  Sign up now


Challenge your current ways of thinking and working

How it works

Challenge your current ways of thinking and working

If you do what you have always done, chances are that you will get what you have always got!

The first step is to assess your herd’s current performance and identify key areas to work on. You can get a wealth of information from your herd's reproductive reports in MINDA. 

In MINDA Reproduction (www.minda.co.nz, Reproduction tab) you can access your DairyNZ Fertility Focus report, as a start.  MINDA Reproduction has many new useful reproductive reports to help you drill down further and identify areas which may require more focus on your farm.

Don't forget that your herd is made up of different age groups, starting from birth.  These groups in your herd have different management needs.  

MINDA reports help you to focus on the performance of these different age groups to identify the group/s that need the most help.


Make a plan

When it comes to a herd’s reproductive performance, there are four key periods in the farming year – late lactation (autumn), pre-calving (winter), pre-mating/mating (spring), and mid-lactation (summer). As part of the 6 Week Challenge, you will be encouraged to set goals for each quarter, assess what needs to be done and record a plan with your team to look back on later and review to make further improvements the following year.

Don't forget each different age group when making your plan for the year.


Do something different

As we said earlier, if you always do what you’ve always done, you’ll always get what you’ve always got. We encourage all 6 Week Challenge farmers to seek input from a rural advisor for ongoing support and one-on-one advice, much like a sports player would from a coach- to help you stay focused on your goals and achieve success.


What you'll get

Information resources for members include:

  • Resource booklet, a simple downloadable guide to the reproductive management year on-farm, split into the four key periods with objectives, targets, strategies and tips for each
  • Editable planning worksheets to record those plans for the team, set goals for the season ahead and review how things went afterwards
  • Planning tools like the annual planner, Ahead of the Herd tool, and other tools to help you schedule key tasks on your farm that can impact reproductive performance
  • Regular emails with timely tips (6 Tips for Success), reminders and news that relates to herd reproductive performance
  • Access to more information on this website, including news and the latest research


Next steps

 After you sign up for the Challenge, remember to:

  • Make you plan
  • Communicate it to all of your staff
  • Find a coach/other farmers to keep you motivated and accountable
  • Check in to our website What's New page regularly for the latest events and news updates
  • Keep in touch with us - read your 6 Tips for Success emails and send us your questions and feedback to info@6weeks.co.nz


Ready to take the challenge? Sign up now

Farmer Stories

 These farmers are taking the challenge and here are their stories

Paula Walker & Steven England - Taranaki

"We want to get to 78% 6-week in-calf rate eventually, but this season we’re aiming for 68%. Last year we improved 4%, and this year we want to go up another 5%.”


Snippet from their final update:

"On closer examination of CIDR cows we found that because of a slower calving spread in our heifers, due to different factors, it was actually our 2 years olds that received most of the intervention. This is something that we will focus on this season and we are confident if we get this right then our intervention levels will be lower again..." 

Take the 6 Week Challenge or sign in to read more of Paula and Steven's story

Dan & Michelle Brice - Otorohanga

"Our 6-week in-calf rate tells us how many AB calves we're gonna get - and we need as many as possible to grow our herd with high quality replacements.”


Farm information

50/50 Sharemilker
600 cows


Snippet from final update:

"I just got rid of 20 cows today. I’m a bit worried about the summer being too dry and I haven’t  seen quite enough surplus so that has taken me down to 605 in-milk cows. I hadn’t planned to do any herd testing but once I got over the ’let’s cut all cost’ mentality I thought better of it. For me, as a sharemilker, the value is on building the genetic merit of the herd and I can’t do it well without herd testing..."


Take the 6 Week Challenge or sign in to read more of their story

Ben McKercher - Canterbury

"We need a tight and steady calving to get more days in milk. Higher production per cow at the same cost - that's the payoff.”


Farm information

Operations manager
Spring calving
425 effective hectares
1574 Holstein friesian and kiwicross cows

Snippet from final update:

"Things are lining up well for mating. Cows are in better condition that last year and there are fewer cows with uterine infections, lameness, and mastitis (SCC is 89,000). Last year 12% of the herd got a CIDR, but this year only 5% needed a CIDR – really happy with this. The cows are bulling so well that my manager rang to say he was struggling to get them out of the paddock because the sexually active group was blocking the gate!"


Take the 6 Week Challenge or sign in to read more of Ben's story.

Kylie McIntyre - Waikato

“We do all AB so it is important that we get things right the whole way through mating. Working with Katrina (from Anexa Animal Health), the 6 Week Challenge helps ensure we have everything covered. We’ve seen real advantages from the effort we’ve put in so far to get the 6 week in-calf rate up - with the tighter calving pattern, increased production, profits and daily management too.”


Farm information

Te Aroha, Waikato
Contract milker
100 hectares
340 cows

Snippet from final update:

"We decided to shorten mating by about 5 days this year to make it a 9 week mating. We will PD about 8 weeks after the end of mating. Because of our short mating we can get away with one scan and get all pregnancies aged and not need any rechecks. It’ll also save us a bit of money only having to do one. My gut feeling is that the cows have got in calf better this year – fingers crossed the PD results confirm it. We do early-aged PD to know which mating they held to (parentage), which calving mob they will go into next spring, and use their expected calving date and BCS to know when they need to be dried off..."


Take the 6 Week Challenge or sign in to read more of Kylie's story

Michelle Adam & Shaun Good - Waikato

"The second person in the shed is watching as the cows come on to the yard, recording numbers, and then we do a comparison between the two lists. It’s a good double check, and it makes for a bit of fun because we turn it into a challenge to see who’s got the best heat detection skills!”


Farm information

Michelle Adam and Shaun Good - 50:50 Sharemilkers
Te Awamutu
128 hectares
400 cows


Snippet from final update:

"With the low payout we’ve reviewed our whole farm system and while we’ll be using Turnips, Chicory and Millet again, we have dropped Maize out of our system. With reduced inputs we’re also planning to go OAD this month. Our next herd test is 10 December and the heifers will go OAD from here, with the cows following later in December/January as the weather dictates. We hope if things get dry that this will help keep condition on the cows... "


Take the 6 Week Challenge or sign in to read more of their story

Dan and Abbie Hinton - Waikato

"We are sharemilkers on two farms in the Waikato, and we’re working to increase the 6-week in-calf rates of both herds to reduce the number of empties. That will give me more scope to cull on quality and increase my herd size with minimum wastage.”


Farm information

Eureka and Puketaha, Waikato
150ha and 125ha
475 cows and 375 cows


Snippett from final update:

"Now because we are doing higher milk solids at the end of lactation, we are still doing expected production with 30% fewer cows. We’re keeping pasture quality by dropping out paddocks and making silage as we go, ready for use in the autumn. They crashed production-wise for a few days at balance date despite the maths saying they were getting enough - it was the fibre missing in the grass. "


Take the 6 Week Challenge or sign in to read more of their story

Enda & Sarah Hawe - Canterbury

"Breeding is very important to us. We spend a lot of time planning and choosing bulls so we need to get the most return on that investment. A high 6 week in-calf rate gives us the selection pressure we need so we can keep the animals we want – it's the benchmark figure that will drive our business forward.”


Farm information

Spring Calving
255 effective hectares
1071 friesian and kiwicross cows


Snippet from final update:

"We have about 70 cows that will be culled hence we are not mating them – a lot of them are 2007-borns. They don’t seem to do as well as the other cows on this farm. We have noticed they come down with milk fever worse and even if they fall into the irrigator ruts – it really knocks them – when most cows just get up and carry on..."


Take the 6 Week Challenge or sign in to read more of their story

Ian & Sonette Alberts - Southland

"A high 6 week in-calf rate means we’ll get milk in the vat earlier, more milking days out of the cows - and our quality cows will calve in that first six weeks which gives them plenty of time to recover and start cycling again before mating."


Farm information

Contract milkers and shareholders
Culverden, Canterbury
1050 cows


Snippet from final update:

"This is the first update since we have moved to Southland. The move has been a big challenge, a good challenge but a big one. Along with everything the new farm has thrown at us, we have had to content with the weather.  The climate is so different from Canterbury and we just cannot predict it.  We’ve been caught out with the rain a few times and there are times when the rain hits, the cows don’t want to get out of the shed (we don’t as well)..."


Take the 6 Week Challenge or sign in to read more of Ian and Sonette's story


What could improving your herd's reproductive performance do for you?

Dairy farming is a numbers game - and whichever way you work it, we believe an improvement to your 6 week in-calf rate is the best way to improve the productivity and profitability of every cow in your herd.

Here’s what it could be worth for you and your farm:

Fewer Empties More days in milk More AB replacements Tighter calving periods
Industry Target 2011 NZ top 25% 2011 NZ average
78% 6 Week ICR 75% 6 Week ICR 65% 6 Week ICR
6% Empty Rate 10% Empty Rate 13% Empty Rate
90% 3 Week Submission Rate 86% 3 Week Submission Rate 79% 3 Week Submission Rate
60% Conception rate 60% Conception rate 52% Conception rate
2011 GAP worth on a 400 cow farm
  • 40 more cows with more days in milk
  • More AB replacement calves
$12,000 Fewer empties
Giving an estimated gain of $28,000 per annum more profit
  • More management choices
  • Better herd/milk quality
  • Greater sustainability
  • More rapid genetic gain
Higher 6 week In Calf = more options
  • $28k+
    Extra Profit

    Estimated scope for increasing operating profit for a 400 cow farm from a 10% lift in 6WICR.

  • 17
    More AB calves

    40 more cows in calf to AB. Expect 17 more AB replacement calves if 6 weeks AB

  • 12
    More voluntary culls

    Improve herd and milk quality through selective culling, giving a higher performing herd, tighter calving and less animal health costs.

  • 2.5 Fewer Service Bulls

    With 6 weeks AB each 10% lift in 6 week in-calf rate means you will require s.5 fewer service bulls - saving an estimated $1,250 bull lease cost.

  • 12 Fewer Empties

    An increase in your 6 week in-calf rate by 10% could result in 12 fewer empty cows.

  • 40 More cows calving earlier

    Opportunity to reduce total mating length, finishing calving before mating starts.