The Irish Cattle Breeding Federation (ICBF) has reported an improvement in the fertility performance of the national dairy herd. This follows the publication of HerdPlus Dairy Calving reports last week.
According to the federation, the average calving interval improved by three days – from 390 days in 2019 – to reach 387 days in 2020.
The average calving interval was 387 days, while the top 10% of herds achieved a calving interval of 364 days, which is surpassing the target of 365 days.
The national average calving interval from 2009 to 2020. Data source: ICBF
The ICBF said it was very positive to see the trend in the graph (above) which highlights the improving fertility of the national herd.
The federation continued by saying: “Given the low heritability of fertility, it is very encouraging to see that the emphasis on fertility in the economic breeding index (EBI) is paying off, with the improving performance in the country.
“The top 10% of herds highlight the potential gains that can be made in fertility despite the low heritability. With the national average sitting at 387 days, there is plenty of scope to continue to make more improvements in fertility.
“The trend over time emphasises that continuing to select high EBI bulls is key to making further progress.”
6-week calving rate
In addition, the six-week calving rate recorded on farms also remained the same as last year at 65%.
Commenting on the six-week calf rate, the ICBF said: “When we look at the six-week calving rate, we also see a similarly positive trend to what we see in the calving interval, with the six-week calving rate going from 53% in 2009 to 65% in 2020.
“For the top 10%, the six-week calving rate is 86%, which is close to the Teagasc target of 90%.”
Fertility traits in the national dairy herd between 1/1/20 to 30/6/20. Data source: ICBF
The ICBF also looked at the percentage of heifers that calved between 22 and 26 months. The average performance recorded for this key performance indicator (KPI) was 71% – up 2% on last year.
According to the ICBF, calving heifers at 22-26 months-of-age is the optimum in terms of maximising profitability of the animals. The survival rate is highest in animals calved at 22-26 months-of-age and, in turn, they achieved an additional 71kg of milk solids over their lifetime.
Looking at the progress over time in some of the other KPI’s, the number of calves/cow/year has gone from 0.84 in 2009 to 0.91 in 2020.
In the top 10% of herds, no cows were being recycled at all. According to the ICBF, recycling cows reduces empty culling rate in the short term, but there are hidden costs to this policy, including: lost milk yield; slippage in calving pattern; and fewer replacement heifers being produced.
This combined with the cost of feeding these recycled cows suggests that avoiding recycling cows is very beneficial.