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The breeding period is the most important aspect of herd management for suckler farmers. If cows do not go back in-calf, then there will be fewer calves produced for sale and a higher culling rate of breeding animals.
In addition, cows that slip in calving date every year due to poor fertility, or using herd sires with inferior genetics, will also negatively affect animal performance and, ultimately, the profitability of the suckler herd.
All of these factors are within the farmer’s control.
Outlined are a series of steps aimed at improving herd management during the breeding season.
1 Give priority to thin cows and heifers: First-calving heifers, cows that calve down in a thin body condition, cows with twin calves and cows that encountered significant calving difficulty should be treated as high-priority animals after calving. They will require some additional feeding to cope with the demands of producing milk and trying to maintain body conditions.
More often than not, heifers, thin cows and those suckling twins will require supplementation with concentrates to increase energy intakes in the days and first few weeks after calving.
Running these animals as a separate group from the main cow herd makes it much simpler to manage higher-priority cows and offer supplementary concentrates to help boost fertility during the breeding season.
Concentrates can be removed from the diet once body condition score has improved in thinner cows, or once animals are turned out to good-quality grass.
Cows with twins may need supplementary concentrates during the breeding season, especially first-or second-cross dairy animals with higher milk production.
2 High-quality grass: Turning cows out to good-quality grass as early as possible after calving will give breeding animals an energy boost, helping to increase cow fertility and bring animals back into heat much faster.
Cows need to be on a rising plane of nutrition prior to breeding. The reason is that cows have an increasing energy requirement during the breeding season, as breeding usually coincides with the period of peak lactation in spring-calving herds.
Therefore, it is important to graze cows on high-quality ryegrass swards during May, June and July as this will help to increase dry matter energy intake.
Grazing swards of high-quality ryegrass will also help to improve body condition in thinner cows, reducing the need for purchased concentrate feed.
3 Breeding groups: There is a limit to the number of cows that should run with a bull, especially for a young bull in his first or second breeding season.
As a rule of thumb, a young bull in his first season should get one cow for every month of age, ie an 18-month-old stock bull should run with no more than 18 cows.
With mature cows and a seasoned stock bull, breeding groups should be around 30 to 35 cows where the aim is to maintain a compact calving pattern. Bigger group numbers will put a bull under severe pressure to cover all animals in a set period.
For herds that calve replacements at 24 months of age, first-calved heifers should ideally be managed as a separate group. Separating heifers can help to increase the number of animals that go back in-calf again, which is often the main problem area when calving at 24 months of age.
4 Managing stock bulls: For stock bulls that will join cows for breeding in May and June, now is a good time to take a semen sample to make sure the animal is fruitful.
While there is still a risk that a stock bull could become sub-fertile later in the season, testing the animal now will give a good indication if there is likely to be a fertility problem during the breeding season. This gives the herd owner time to replace a stock bull if necessary.
Bulls that were used to serve autumn cows should be removed from these animals and allowed to rest before serving spring cows.
Supplement the bull with 3kg to 4kg/day of concentrates to improve body condition prior to joining cows.
Where a new stock bull was purchased earlier this year, gradually wean the animal off concentrates to avoid excessive loss of condition.
5 Mix early and late-calving cows: Where herds calve in a compact block, grouping all the early calving cows together will put the stock bull under pressure to serve them all.
Grouping them means there will be days when multiple animals are in heat at the same time.
Mixing early and later-calving cows takes the pressure off the stock bull and makes it easier to maintain a tight calving period.
6 Keep stress to a minimum for AI: If AI is the preferred breeding method, then the less stress cows come under the better. Good, secure handling facilities mean cows can be easily separated, restrained, inseminated and returned to their breeding group without stressing the animal.
Reducing stress will help to increase conception rates in cows. Always move a cow at the animal’s pace. Rushing the cow will only rouse the animal, which is not ideal prior to insemination.
Rather than trying to isolate a single cow for insemination, it is easier to bring in a small group of cows every time an animal has to be inseminated.
Feeding cows a small quantity of concentrates during the breeding period will familiarise cows with handling. This means cows can be brought in for insemination with ease.
7 Heat detection: Where cows are being served to AI, heat detection is crucial. There are various aids available, from tail painting to electronic heat aids that alert herd owners through their phone.
When monitoring cows for heat activity, check cows at least four times a day, with each period lasting 20 to 30 minutes.
Early morning and late evening are usually the best periods to notice mounting activity. Where time is limited, using a teaser bull is one of the best ways to identify animals in heat.
For herds using stock bulls for breeding, it is still worthwhile spending some time watching for cows in heat and ensure that bulls are working effectively.
8 Record service dates and watch for repeats: Record the date and tag number of cows seen in heat and being served. This way, you will have accurate information to watch for repeat breeding activity.
There will always be a few animals that repeat every cycle. But if you notice multiple animals coming back in heat again three weeks after service date, then there may well be an issue with the stock bull and you can take action early.
A sub-fertile bull is worse than an infertile bull. An infertile bull will be detected fairly quickly. A sub-fertile bull will positively serve some cows, but leave other cows empty, making this type of animal harder to detect.
If left undetected, a sub-fertile bull will result in the calving period dragging on into the summer. In herds with two or more stock bulls, rotating herd sires after the first six weeks of breeding activity helps to reduce the risk of a sub-fertile bull leaving cows empty.
9 Mineral supplementation: Mineral supplementation is crucial for a positive breeding period. Make sure cows are properly covered for key minerals such as iodine, selenium and copper as a deficiency will affect cow fertility.
Giving cows a bolus will provide a slow release of minerals during the breeding season. Mineral buckets are also effective, but need to be replaced regularly. As a rule of thumb, use one bucket for every 10 cows in a breeding group.
10 Identify repeat offenders: Cows with poor fertility will always calve at the end of the calving period every year. Most of these animals will be slipping in calving date, getting later and later year on year.
It usually only applies to a small cohort. Given the small margins in suckler cows, farmers should seriously question the merits of holding these animals for another year.
Check through the herd records for the last few years and identify those cows that have repeatedly calved late.
This is the year to pull these cows out and either fatten after weaning in autumn, or sell now as a cow and calf unit.
If sold now, there is no temptation to give a poor-performing cow another chance at breeding again as poor fertility performance will not change.
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