Before you consider finishing with artificial insemination (AI), it is important to determine how many cows may not yet be in-calf.
The recommendation is one mature bull to every 15-20 cows, and to continue to use AI for 10-14 days after the bulls have been introduced.
For a spring-calving herd, there are three groups of cows currently on your farm:
- Those served more than 32 days;
- Those served less than 32 days;
- Those yet to be served.
Once you have identified the number of animals in the different groups, decisions need to be made regarding what may possibly need to be done to the animals yet to be served, or those not yet in-calf.
Scanning
Cows can be scanned from around 28 days after service to determine their pregnancy status.
By carrying out scanning you will be able to tell what is going on, and this will allow you to make management decisions that may need to be made.
These could include the use of a hormonal treatment, a wash-out, or for a late-calver, simply allocating more time.
The sooner a cow that does require treatment is identified and treated the better; this will give the cow a better chance of going back in-calf.
Using beef AI
If you have determined the number of animals not yet in-calf and that you have that correct number of bulls, the continued use of beef AI may still be an option.
The Dairy Beef Index (DBI) ranks beef bulls – for use in the dairy herd – according to their genetic merit, for a range of calving performance and carcass performance traits.
The use of beef AI gives you the security of calving ease, short gestation length and sires with higher confirmation and weight, all of which makes for a more sellable calf.
The use of the DBI can produce more balanced cattle with more favourable economic returns.