Benchmark against best when tackling deficient herd fertility
Aim for calving interval and spread targets
THE BASIC conditions required for good herd fertility are healthy cows in good body condition and a fertile bull or, where AI is used, top-rate heat detection. To know the fertility performance of your herd you need to know what are the achievable targets and to record the reproductive performance of your herd for comparison.
The key fertility targets have received a lot of attention but achievement is still well below what is possible or satisfactory on many suckler farms. Targets being achieved by top performing herds are as follows:
- An average calving interval of 365 days;
- 0.95 calves born per cow put to the bull;
- 60pc of cows calved in the first month of the calving season;
- All cows calve within 12 weeks;
- Calf mortality of 2pc at birth to 3pc at 28 days.
These are exacting targets and achieving them depends on a high level of herd management. Hitting the targets on calving interval and calving spread will go most of the way in rectifying deficiencies in herd fertility.
Data from the Irish Cattle Breeding Federation (ICBF) shows that, for the beef herds on their database (which are most likely to be above average in performance), the top 15pc have a calving interval of 364 days, whereas for the bottom 15pc it is 434 days. The national average is 399 days.
It is estimated that the average number of calves born per cow per year is about 0.83 or 83 calves per 100 cows bred. Again, the best performing herds are achieving 0.95 calves per cow per year from a combination of short calving interval (365 days), tight calving spread (four months or less) and low calf mortality (4pc or less).
The table (see below) shows an estimate of the improvement in output per cow in going from average performance to the top 15pc for cow productivity.
An increase of €65 in output per cow can be obtained by improving calving interval and reducing mortality.