Farmer Focus: Disappointing in-calf heifer rate forces rethink
© Steffan Hill And just like that, autumn has blown in. It feels like yesterday we were starting breeding and watching as grazing was taking off.
With the fertiliser ban quickly approaching, before we know it, we’ll be closing up fields for the winter.
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Up until a week ago, we had experienced about three weeks of minimal rain, resulting in a severe drop in growth (to just 33kg dry matter/ha a day), stemming of swards and decreased rotation lengths.
Thankfully, we can fill this deficit with surpluses of high-quality baled forage we made back in early summer.
Ensuring we protect and build our average farm cover as we move into autumn is vital so we can graze as long as possible this season, when every extra day at grass is worth £1.56 a cow.
Cycling replacement heifers for breeding is proving a challenge.
After pregnancy diagnosing this year’s batch of heifers, all we could achieve was a measly 42% in-calf to sexed semen, where we should be hitting at least 50%.
For 15 years, our R2 heifers have been reared off the milking platform.
We have used a controlled internal drug release synchronisation programme to manage time efficiently while using hormones to ensure all animals are presented before artificial insemination (AI) – in theory – at a cost of £50-£60 an animal.
All effort was taken to ensure every animal was at least 60% of mature weight, grazing high-quality grass and receiving every vaccine and wormer needed.
Even when we look at bull and AI technician data, there is little to no correlation. With this level of inconsistency, risk and cost must be challenged.
One path we can take is to cut out breeding replacements from heifers.
With genomic testing in crossbred herds in its infancy, how many R2s are actually above herd average once calved? How many will underperform in the first lactation? Is this really the fastest way of achieving genetic potential?
Our data suggest that breeding more replacements from milking cows with better conception rates (55%) each year is cheaper, more reliable (using individual milk records), and should increase the first service conception rate in heifers using stock bulls.