Batch breeding heifers can be successful as soon as they reach target weight, irrespective of age.
Heifers should be bred to easy calving AI dairy bulls.
As heat detection can be difficult with maiden heifers, which are usually grazed some distance from the farmyard, a batch breeding system may be the best way to ensure that heifers are bred early in the season.
Too many farmers let them run with an AA bull, for convenience reasons.
But this is a wasted opportunity to speed up herd EBI — and dairy heifers will be scarce and valuable in the future.
Prostaglandin synchronisation regimes work extremely well with cycling heifers in Moorepark. The protocol involves tail painting all heifers and inseminating all heifers showing heat in the first nine days of the breeding season.
Heifers not inseminated get a prostaglandin injection and are inseminated when they show heat in the next three to five days.
Heifers that fail to show heat get a second injection of prostaglandin 10 days later.
These heifers are inseminated at standing heat or receive fixed-time AI at 72 and 96 hours after the second injection.
All heifers are observed for repeat heats, and a bull is introduced five to six weeks after the start of the breeding season.
This system typically results in about 65% to 70% conception to first service in Moorepark.
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