Making improvements in fertility performance on any dairy herd has to be a two-pronged approach. Using genetics to improve cow fertility by selecting bulls with high PTAs for fertility is undoubtedly a long-term approach with a minimum of five years needed to reap the benefits.
In the short term, much can be done to make fertility gains, with some of the Dairylink project farmers focusing on issues like heat detection, improving fertility record keeping, and targeting cow condition and optimal heifer weights for breeding, to improve the situation on farm.
Poor conception rates, extended calving intervals, and low in-calf rates are all common fertility problems for dairy farmers. Many of the Dairylink Ireland project farms are no different, with problems ranging from spread calving patterns to poor heat detection. However, the one common problem for all farmers is the cost of infertility to the business, with costs ranging from £3 to £4 per cow per day not in-calf, depending on the milk price and cull cow price use in the calculation.
Genetic improvement within a herd may be slow to register a change in performance, but is still the most effective method to drive performance on farm – not only fertility performance but other traits like milk components and animal health traits can also be improved by simply selecting the correct sire for the system.
Making the correct decisions around bull selection for your herd is critical and should not be taken lightly.
In terms of sire selection, what are project farmers focusing on and is fertility the only issue when it comes to selecting bulls for the herd?
All cows have been tail painted (crayoned) on the farm over the weekend. The breeding season started on 1 May this year, which is 10 days later than last year to tie in better with growth and ground conditions on the farm next spring.
This year, David felt calving started slightly early, with grass demand increasing approximately 10 days too early for the farm given its location and soil type. The plan is to check all cows three weeks into breeding for non-active cows and single out for vet inspection.
Sire selection is 100% based on the EBI index, with David focusing on high milk solids and fertility sires for his herd. David uses the ICBF sire advice facility, which pairs sires to cows in the herd from the team of sires selected at the start of the season in an attempt to deliver maximum genetic gain, and so far he has been pleased with this tool.
Replacement heifers will be brought back to the home farm this weekend to a grazing paddock on the platform. The paddock has been selected strategically close to the crush to allow David to run heifers in to inseminate, keeping it a one-man operation.
The 20 heifers which have been weighed are all within the optimal breeding weight of 350kg-380kg and will be fitted with a Kamar heat detection sticker on the tail head. The heifers will be bred to AI once and then returned to the out-farm with a stock bull.
Sire selection for the heifers was based on high fertility but also calving ease. The bull listed in the table as LWR will be used extensively on the heifers this year. Calving ease is important to David, not only from a labour-saving perspective at calving, but also for limiting the stress and calving difficulty for the heifers.
A synchronising programme will be used on the heifers with a prostaglandin injection given to the heifers and 10 days of AI breeding.
With the Kamars attached, David will monitor and breed heifers for the first five days. A prostaglandin injection (2ml Estrumate) will be given to all heifers not previously bred at the end of day five.
These heifers, which will show signs of heat between two and five days after the injection, will then be bred 12 hours after a standing heat.
A key focus point for David this year will be to develop a more compact calving profile in the herd to allow the maximum utilisation of grazed grass on the farm. With cows performing very well currently in terms of output (see Dairylink weekly data table) cow condition must be maintained now that breeding has started. Cows are now on second rotation grass with 2kg concentrate – this will be held for the first six weeks of breeding, after which concentrate will be removed or reduced. David is targeting a 12-week calving period with calving starting on 1 February each year.
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