What are the results looking like?

Not too dissimilar to how many New Zealanders are feeling after a lengthy couple of years; the 2022 Spring season was slow.  Although late Winter pastures initially seemed to be stepping up and providing plenty of quantity, the quality of this pasture came under serious scrutiny; limiting cow intakes (and rumination rates for those with collars) and as a result limited production and general cow performance. 

It was still to be seen as to how this would affect mating so we were keeping a close eye on submission rates. Submission rates across the practice (somewhat surprisingly) were on-par with previous years indicating that all was well. It wasn’t until we were well into mating and started receiving reports of low non-return rates that it was evident not all was well. Non-return rates are an indirect measure of conception rate (ie. % of cows conceiving to any given mating event). Low non-return rates were indicating that cows were potentially not holding to their AI matings as well as they should be. 

Aged scanning gives us a very accurate measure of conception rate because we know exactly when cows conceived.  As you can see from the table above herd conception rates fell across all regions of the practice in the order of 4-5% this season.  This may seem like a rather insignificant change however when you apply it across hundreds of farms it does mean that some individual farms dropped in the region of 30%!! 

Collapses in conception rate of this magnitude appear to have had a major impact on overall performance across the practice and given that it wasn’t a submission rate issue even interventions didn’t help!  Referring to the table above you can see that regional empty rates and 6-week in-calf rates have slipped by quite a margin using data from the herds we have scanned to-date.

So what to do about poor conception rates? 

• Feed and monitoring milk production parameters (did cows peak as high, if not then why not), is your milk protein curve tracking well ahead of mating – talk to one of our vets
• Cow condition at calving and loss of condition between then and mating – regular mob Body Condition Scores by an accredited person
• Consider general cow health, disease levels and system stress
• Maximise cycling rates ahead of mating – conception rate improves with every cycle a cow has
• Always work on heat detection – use all tools at your disposal; collars, teaser bulls, scratchE’s
• Well-grown and well-managed first calvers

Now is the time to look into any issues and start making plans for next season as it starts with BCS at calving.  Talk to one of our In-Calf advisors today if you are wanting to know more.

Dr Greg Lindsay, Farm Vet & Regional Manager Kopu

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