Advice for dairy farmers: Maintain condition in run-up to  breeding

Check records regularly and give particular attention to animals within 18 to 21 days of their previous heat or service.

Strategic use of tail paint colours or other aids will help to simplify heat detection.

Good observation of cows, early in the morning, at midday and late evening is essential.

Stock bulls can become intermittently infertile during the breeding season, especially if they get lame or suffer any illness.

Not only should you have checked bull fertility at the beginning of the season; keep a close eye on him during the season, to check if cows are repeating.

Vasectomised bulls with chin balls are used for heat detection, especially in large herds. At least two of these are necessary per 100 cows.

Make sure their chin balls are full of paint.

Vasectomised bulls are generally more active and are safer in the first year.

It is better and safer to change these animals every year, as they can become dangerous later in life. All bulls should be tested free of BVD and other contagious diseases.

There are other aids to heat detection on the market, including some computerised systems which give good results.

Difficult calving and twins can reduce fertility as much as 50%, especially if proper veterinary follow-up treatment is not practised. Lame and sick cows will not only fail to show heat, but generally they will not cycle.

Diseases such as ketosis, milk fever, digestive upsets etc will have the same effect. But 93% of cows, which are properly fed and free of problems, should be showing heat within 40 days of calving.

Ensure that your herd has a clean bill of health from your vet regarding the many diseases that might be present.

Ensure all vaccinations are completed. Don’t wait until serious problems arise. If you have any doubt about disease problems, you should get your milk tested through your co-op’s herd health service.

Proper nutrition is vitally important for breeding performance. Plenty good quality grass should be the basis of nutrition, plus supplementary feeding as necessary.

One of the main findings in Teagasc Moorepark fertility trials has been that cows which lose less than a quarter of a condition score between calving and breeding are 50% more likely to be in-calf after six weeks of breeding, than cows which lost over half a condition score.

Therefore, do everything possible to avoid loss of condition in the run-up to and during the breeding season.

Batch breeding heifers

You can satisfactorily breed heifers as soon as they reach the 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.

For convenience reasons, many farmers let them run with an Aberdeeen Angus bull. But this is a wasted opportunity to speed up herd EBI improvement.

Prostaglandin synchronisation regimes work extremely well with cycling heifers. 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 times AI at 72 and 96 hours after the second injection.

All heifers are observed for repeat heats, and a bull is introduced five weeks after the start of the breeding season. This system typically results in 60% to 70% conception to first service, at Teagasc Moorepark.