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Top tips in advance of breeding season 2021

As the calving season on many farms nears an end the thought of the breeding season is just around the corner. Calving season 2022 depends on when breeding season 2021 starts. Now is the time, in advance of the breeding season, to plan out calving season 2022, advises Catherine Egan, Beef Specialist

What date do you want calves born from? When do you want the calving season to end?

Both answers will depend on when calving season this year ends and what date your breeding season starts. Based on 283 calving gestation you can see in Table 1, a farms breeding season will need to commence April 25th 2021 to start calving February 1st 2022. If there is a 12 week calving spread on the farm the last cows will have calved on this same week. Hence some farmers aim to calve all cows in an 8-10 week period to leave a break between calving and the start of the breeding season. In order to maintain a 12 week calving season in 2022, the bull will have to be removed by July 15th 2021 to avoid calves being born in May 2022.

Table 1: Date of service and calf due based on 283 day gestation



Stock Bull

With four out of every five calves born on beef farms sired by a stock bull, a stock bull’s fertility is vitally important. The stock bull on your farm is key to maintaining a compact calving period, maximising the genetic potential and value of the calf crop, and overall herd profitability. Here are 10 tips to assess your bull in advance of breeding season


  1. Bull fertility check- A bull’s fertility status can change, from year to year. Therefore, it is good practice to have a fertility test carried out on the stock bull, prior to start of breeding season. It is estimated that twenty five percent of stock bulls are sub-fertile. The cost of the test is very low if you compare it to carrying empty cows for the summer and results are available to you before the technician leaves the yard.
  2. Body Condition score- A bull must be able to maintain body condition score (ideally BCS 3), repeatedly mount and serve cows for 12 weeks and have a long working life in the herd. If you have bought a bull, find out from the seller what diet and current concentrates he is being fed and vaccinations he has received.
  3. Health- A blood test might be useful to check for BVD, IBR, Johnes Disease and Leptospirosis. If vaccinating or treating for parasite these should be administered at least six to eight weeks in advance of the breeding season as they could lead to reduced fertility. Consult your vet for advice on the health of the bull. Remember a young bull in his first season should serve no more than 20 cows.
  4. Nutrition- It is important to avoid sudden changes and not to over feed the bull as this can reduce fertility and lead to feet problems. He needs to be fit but not over-fat.
  5. Visual check- In advance of the breeding season check feet and legs well and take remedial action if required.
  6. Observe- Watch the bull working to check he is serving cows correctly.
  7. Rotate- If possible rotate bulls or scan cows early so that an infertile bull or sub fertile bull can be identified early.
  8. Records- Record when you see a cow being mated and watch for signs of cows coming on heat repeatedly.
  9. Issues- If a large number of your cows are repeating, you need to take action to find out what is wrong. You must be prepared to start using AI or if you have a second bull with another group of cows, he may be utilised to serve more cows.
  10. Pregnancy scanning - When it is at least 35 days since the last cow in the herd could have been served then you should consider scanning the cows. It offers many advantages.

Tune into Catherine's latest Beef Edge podcast where she talks to David Argue, Teagasc about buying a new stock bull. Click on the image here below

For more from Teagasc Beef check out the Teagasc Beef home page here