Breeding will get underway on many suckler farms during May. Therefore, farmers need to think about sorting cows into different breeding groups if more than one bull is used, or if the herd uses a combination of AI and stock bull.
Outlined are five options for sorting breeding groups in spring calving suckler herds.
The most straightforward option is to operate a single breeding group with cows mated to a stock bull or AI.
In smaller herds of 15 to 20 cows, it may be more cost-effective and labour-efficient to purchase in-calf replacements every year, rather than keeping two to three heifers annually as a separate group.
Running one breeding group is more time-efficient, especially when using AI as heat detection and handling cows is easier to carry out. This will help increase conception rates.
For larger herds with two or more stock bulls, or using AI and stock bulls, it may be an option to run a maternal group of cows and a second group of animals to a terminal sire.
The maternal cows should include the most productive animals in the herd. Crossed to a maternal bull, these animals are ideally suited to producing herd replacements.
There are plenty of sires that combine milk and carcase traits, so male progeny will not be affected in terms of growth rates or conformation.
Cows that are less suited to producing replacements are then run with a more terminally bred sire, removing temptation to keep any heifers from these cows as replacements.
If there are two or more breeding groups, it may be worthwhile mixing cows to get a more even spread of early and mid-season calving cows.
This should help spread cows coming back into heat over the breeding season, easing the pressure on stock bulls to get cows served.
Every herd will have a few cows that run late every year and, usually, it only applies to four or five animals.
If these cows will be retained, and there is a breeding group of replacement heifers running with a bull, it may be worthwhile running the late-calving cows in this group also.
Chances are the bull running with replacement heifers will be an easy-calving animal with a short gestation period.
This could help pull these cows forward for next year. Also, the handful of calves born to late-calving cows are out of sync with dosing and other routine tasks in the main breeding group.
Having these animals running with the heifers will make it easier to target worm and clostridial treatments for late-born calves compared to mixing them in with the main herd.
On farms with one stock bull, it may be an option to run a few cows in a smaller, separate group for AI, taking the pressure of the stock bull.
It will all depend on the availability of grazing ground, handling facilities and the ability to spend time watching for heats and bringing in cows for insemination.
Choose the more productive cows for such a group as they are likely to be more fertile. Cows that are quiet are also better suited to AI for handling purposes.
Just giving these cows one service to AI, then run any repeats with the stock bull can help to take the pressure off the herd sire during the peak breeding period.
In smaller herds retaining heifers for breeding, this may be a more cost-effective option that running a second stock bull.