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Mid-season breeding decisions to improve farm profitability

Mid-season breeding decisions to improve farm profitability

Effectively at half time, Michael Donoghue, B&T Dairy Advisor, Teagasc Galway/Clare, writes on the decisions farmers need to make in the second half of the 2024 breeding season to ensure it’s a success.

Most spring-calving dairy herds are now entering the fifth week of the breeding season. All cows that have been selected for breeding for the 2024 season should be served at this stage. Any problem cows should have been scanned with remedial action taken as required. Breeding for replacements, if not already, should be finished, as these late heifers will always be on the back foot and require a lot of time and cost to catch up with the ‘early’ heifer.

When selecting beef AI or stock bulls, use only easy calving and high Dairy Beef Index (DBI) for the remainder of the breeding season.

Length of breeding season

Over the last decade or so through the introduction of the EBI, the quality of dairy breeding has improved dramatically. This is seen especially in the fertility improvement in dairy herds. Herds are now calving more compactly at the start of the grass growing season. To take advantage of this better breeding, farmers need to question: When do I want to finish calving in 2025?

Table 1: Guideline expected calving dates based on serve date and gestation length of 283 days

AI serve date Calving date
June 1 March 11
June 15 March 25
July 1 April 10
July 15 April 24
August 1 May 11

While there is no one case fits all, most dairy farmers should aim to finish their breeding season between July 1 and July 15. This will positively impact your farm profitability in 2025 by removing late calvers, thus cows get more days in milk - especially if the herd dries off over the winter. Additionally, calf value will be increased as the late calves tend to be lower value and have the most health problems. And finally, even the late calvers in 2025 will have ~ four weeks before breeding commences to recover from calving, thus giving them a far better chance of going in calf in 2025.

Cow activity

During the first round of breeding, there is always lots of cows in heat together, resulting in lots of activity/mounting and, as a result, identifying cows in heat should be relatively straight forward.

However, as the breeding season moves into the second and third round, there is a big drop of in activity/mounts. On average, during the first round, we can get 40 to 50 mounts for a cow in heat. This, however, can drop to 10-15 during the second round, making identifying cows in heat a lot harder. There is no single solution to this, but some options to help with identifying cows in heat might include: using teasers bulls; keeping tails paint topped up; using bulls but continue to AI; or heat detection systems/collars.

Bull power

A question often asked is how many bulls do I need? Below gives a guide to how many cows a bull can put in calve for a relatively compact spring calving herd:

  • One mature bull per 20-25 cows;
  • One young bull per 10-15 cows.

The second part in determining how many bulls are required is deciding when the bulls are being introduced to the herd and getting a handle on the fertility status of your herd.

Table 2: Example of number of mature bulls required for a herd size of 100 cows at various stages throughout the breeding season

  Breeding cows Submission rate Conception rate Cows in calf Cows not in calf Mature bulls required
Week 0 100       100 5
Week 4 100 90 55 50 50 3
Week 7 100 90 50 73 27 2
Week 10 100 90 50 85 15 1

In the example above, if AI is just being used for the first round of breeding, submission rates are very good and conceptions are good, then three bulls should be enough. If there are individual days with a lot of activity, cows on heat, then cows should be artificially inseminated rather than relying on the bulls. It is also important to give bulls a ‘day off’. This will not only give the bulls a rest, but will also help to keep them keen when they are with the cows.

Bull safety

Bull safety is always an issue, but extra caution is required as we enter the last few weeks of the breeding season. Bulls can become more agitated and farmers can get lax around a bull as he has been with the cows a while. Make sure bulls are ringed, have a rope or chain on the ring, and have warning signs up. Ideally when breeding season is finished, have somewhere safe to keep the bulls or bring to beef.