The breeding season is one of the most critical periods in the farming calendar, setting the foundation for herd performance and milk output next year. The breeding season is now well underway on most farms and many future replacement heifers will already have been conceived BUT the breeding season is far from over. One of the main objectives at this stage is to maximise the number of cows in calf by the end of the breeding season and this requires a proactive approach.

 

Breeding Season Targets:
Submission rate:
Aim for a submission rate of 90% in the first three weeks of the breeding season. This means that three weeks after the mating start date, 90% of eligible cows (cows calved greater than 35 days at the start of the breeding season) should have been bred. Achieving a high three-week submission rate is a critical driver of fertility performance in a seasonal calving system. If this target is not being met it is important to understand why:

• Heat detection efficiency and accuracy: Missing too many heats will lead to poor submission rates. The use of heat detection aids such as tail paint, scratch cards or crayons can significantly improve heat detection performance and should be implemented where not already in use.
• BCS and nutrition: Fertility is closely linked to energy balance. Ensuring cows maintain an adequate BCS is vital.
• Once the first three weeks of breeding are complete, the level of mounting activity in the herd will decrease as the number of animals in heat decreases. This makes heat detection more challenging:
  •    Increase the intensity of heat detection.
  •    Monitor records closely to identify those cows due back in heat. This will improve your heat detection performance.

 

Non-return rate:
The target is that at least 60% of cows which have been bred in the first three weeks will not be presented for breeding again (non-return rate). It is important to remember that non-return rate is not the same as conception rate, as pregnancy has not been confirmed in these cows, however, the non-return rate can be an early indicator of low conception rates. 

 

Breeding Season Pitfalls to Avoid:
•    Failure to identify non-bullers:
Cows that are calved greater than 35 days but have not been seen in heat need attention. By identifying these cows and treating them early you give them the best chance of going back in calf and being retained in the herd.
•    Synchronisation repeats: 
All repeats from a synchronisation program will happen between 18 and 24 days. Depending on the number of animals in the synchronisation program, this can put stock bulls under too much pressure. If 2 or more repeats are expected per stock bull per day it is best to remove the bulls a couple of days in advance, apply heat detection aids and AI these repeats.
•    A lull in calving after insemination finishes:
 Bulls need time to settle into a routine once they are left off with the cows. If a stock bull is being introduced during the breeding season it is important to allow for this settling-in period by continuing to inseminate for the first 10 to 14 days following the introduction of the bull.
•    Bull power: 
A common pitfall is underestimating the number of bulls needed for the number of empty cows. One young bull is needed for every 10 empty females and one mature bull for 20-30 empty females. Also, if more than two cows are in heat per mature bull on one day, then these should be inseminated.
•    Underperforming Bulls: 
A bull that underperforms can have a detrimental effect on your calving pattern next spring. Throughout the breeding season, bulls should be closely monitored for signs of lameness, injury, illness or loss of BCS. Again, recording heats and ensuring a non-return rate of at least 60% is crucial to monitor the performance of stock bulls. 

 

FarmOps:
FarmOps is Munster Bovine’s herd management app. The Breeding and Fertility section in FarmOps allows heats and serves to be recorded. All this information is then used to supply herdowners with some vital breeding metrics:
•    Cows calved > 35 days but not seen in heat.
•    Cows that are 18-24 days since their last serve and are due back in heat.
•    Number of stock bulls required – calculates the number of potentially empty cows in the herd and tells you how many stock bulls are required.

 

Breeding quality beef calves
Beef calves have been an important source of income on dairy farms this year, with strong demand driving excellent prices for dairy-beef calves. To maximise this opportunity, it is essential to use a team of beef bulls with a high Beef Sub-Index and match each bull to the appropriate group of females—heifers, second calvers, cows and mature cows.
Matching bulls to specific cow types within the herd helps maximise calf quality while minimising calving risk. Easier-calving bulls should be used on maidens and second calvers, while slightly stronger bulls can be used on mature cows that have the capacity to calve larger calves without difficulty. Within the Munster Bovine catalogue, bulls are clearly identified for each cow category to support this decision-making.
Calf quality is now a major driver of value. Calves from higher beef merit sires are attracting premium prices in marts and helping to secure repeat customers on farm. As discussed in the recent webinar, breeding with your end buyer in mind is essential. For example, if your customer prefers Angus calves, using a team of high Beef Sub-Index Angus bulls across your herd will help ensure a consistent supply and maintain repeat customer. Table 1 outlines an example of an Angus bull team that could be used to cover different females. These bulls combine high beef merit with calving ease, delivering strong-performing calves while providing peace of mind.

Table 1 Example Angus bull team for a dairy herd

 

Using a wider team of bulls also helps to spread risk, reducing the impact of any individual bull underperforming and supporting improved fertility performance across the herd.
For the second half of the breeding season, greater emphasis should be placed on gestation length when selecting beef bulls, as this can help tighten the subsequent calving season. Bulls with lower (more negative) gestation values will produce calves with shorter gestation lengths. The number 1 Angus for gestation currently available in AI is AA9607 VENGABUS.

 

Munster Bovine’s most recent webinar featured Teagasc Dairy Specialist Stuart Childs who spoke all about his own farm and how he manages his breeding season. Stuart’s farming journey is fascinating, and he provided many valuable insights into how he has progressed his herd. He was joined by Tom Baker, Commercial Manager with Munster Bovine and Munster Bovine AI technician Mike Kenneally who provided tips on how to maximise conception rates through AI and what herdowners can do to ensure their breeding season runs smoothly. All of this was expertly facilitated by Munster Bovine Vet Dennis Howard. To watch this webinar back scan the QR code below. This webinar is also available to listen to as a podcast on Spotify.