No silver bullet: stick to the knitting, nail repro targets

In this article, LIC senior reproduction solutions advisor Jair Mandriaza provides commentary on the 2018/2019 national reproduction statistics, and sees good cause for optimism.

Reproductively, it’s been somewhat of a rollercoaster ride during the last six years.

But, nationally at least, there’s been a significant rebound in repro performance over the past two years, and now it’s a matter of building on sound recent gains.

Based on 4207 seasonal calving herds(Fertility Focus Reports, via MINDA), data suggests farms have most recently achieved their highest ‘6 week in-calf’ rates in five seasons.

Of the approximately 2.3 million cows analysed, the average 6 week in-calf rate now sits at 67.5% (the last time it was at this level was in 2012; by 2016 the same figure had dropped to 65.8%). 

Meanwhile, the average not-in-calf rate today sits at 16%.

The real kicker is context. During that same period (2012 to 2019), the average on-farm mating length, and therefore calving spread, has noticeably tightened. 

As LIC’s reproduction advisor, I commonly hear a farmer-held belief that cows are ‘harder and harder to get in-calf’ and that ‘not in-calf rates are higher than ever’. 

My response to that is ‘harder’ and ‘higher’ compared to what?

Data tells us the average mating length is now down to fewer than 11 weeks (several years ago the average mating length stood at 14.5 weeks).

And we know that as we shorten mating lengths by one-week increments, the likely compromise is a further 1-2% more cows failing to get in-calf per week.

The upshot is that excellent progress is being made despite changing farm practices, increased regulations, and challenging payouts.

My message is to keep concentrating on the fundamentals.

That’s because a good 6 week in-calf rate will always be the driver in reducing the not-in-calf rate.

In terms of repro, top-quartile herds achieve an average 6 week in-calf rate of 76.5%, with a not in calf rate of 12%, and they’ll do this with an average 10 week mating.

Numbers also show that in the last 10 years there’s been great improvements in several areas that contribute to reproductive performance, particularly the management of young stock (the very basis of it all).

In nearly every area of repro performance, I’m increasingly seeing two- and three-year-olds outperforming other groups of cows in the herd. There’s been higher emphasis on

drying cows off based on BCS targets at calving, and farmers are generally putting in more targeted efforts in heat detection accuracy and processes.

Meanwhile, farms continue in their quest for an increasingly efficient animal through targeted breeding schemes. 

Of course there are, for most farmers, still a lot of opportunities to capitalise on their gains and improve further.

Remember, there’s no silver bullet when it comes to fertility and repro, so don’t bother seeking one. The key is to know the fundamentals toward repro improvement, and then stick to your knitting.

It could turn out that 2019 is the highest reproductive performance year since we started formally measuring repro via the Fertility Focus Reports (2008/09 season).

I shall look forward to finding out just how it all pans out this season and reporting it back to you.

National reproductive performance figures 2017 - 2018.