Pregnancy scanning – a key management tool for suckler herds
While there is a cost involved, pregnancy scanning should be viewed as an investment rather than an expense, as the information gained can improve herd fertility, reduce winter feeding costs and support better management decisions, Joe Mahon, B&T Drystock Advisor, Teagasc Naas, tells us more.
The objective of every suckler herd is to produce one live calf from every cow every 365 days. Empty cows and extended calving intervals reduce herd profitability by increasing feed and maintenance costs while reducing lifetime calf output. Pregnancy scanning helps identify these issues early, allowing farmers to make informed decisions before winter housing.
Scan at the right time
For the most accurate results, cows should be scanned approximately 30–40 days after the last possible service or after the stock bull has been removed. At this stage, ultrasound scanning can accurately confirm pregnancy, estimate the expected calving date and identify twin pregnancies.
Scanning later in pregnancy reduces the accuracy of ageing the foetus and makes twin detection more difficult, while very early pregnancies may also be harder to identify.
Identify empty cows
The greatest benefit of pregnancy scanning is identifying cows that are not in calf. Empty cows can be removed from the breeding herd before winter, reducing feed, labour and housing costs. Their calves can be weaned earlier, while the cows can be finished and sold through the mart or factory where cull cow prices are strong in recent times.
Removing barren cows also reduces stocking pressure and, on highly stocked farms, can help lower the farm’s organic nitrogen loading. Separating these cows from the main herd also reduces disruption caused by cows returning to heat and decreases the risk of young bull calves being injured through mounting activity.
Plan for calving
Pregnancy scanning provides an accurate estimate of gestation stage, allowing farmers to predict calving dates, particularly where stock bulls are used and individual service dates are unknown.
Knowing when cows are due to calve allows them to be grouped according to nutritional requirements. Late-calving cows can be managed on moderate-quality forage to prevent over-conditioning, while thinner cows, first-calving heifers and cows carrying twins can receive better-quality silage or additional concentrate supplementation where required.
Grouping cows by expected calving date also simplifies vaccination programmes, housing management and labour planning during the busy spring calving season.
Detect twin pregnancies and monitor fertility
Twin pregnancies are most accurately detected before 12–14 weeks of gestation. These cows require closer attention during late pregnancy as they have higher nutritional demands and are at greater risk of calving difficulty and retained placenta.
Pregnancy scanning also provides an opportunity to assess overall herd fertility. The target is that less than 5% of cows should be barren after the breeding season. A higher barren rate may indicate issues such as poor bull fertility, inadequate nutrition, mineral deficiencies or reproductive disease. Early identification allows these problems to be addressed before the following breeding season.
Scanning results can also identify cows that conceived late. These animals can be considered for culling after weaning, helping to shorten the calving spread and improve long-term herd performance.
Better winter feeding and management
One of the greatest advantages of pregnancy scanning is the ability to match winter feeding to the needs of individual cows. By grouping cows according to expected calving date and body condition score, farmers can make better use of available silage and concentrates while avoiding problems at calving from cows becoming over conditioned (BCS >3.25) and the unnecessary extra feed costs involved.
Close-up cows can be monitored more frequently, calving facilities prepared in advance and veterinary assistance organised if required. Ultrasound scanning may also identify reproductive abnormalities, including uterine infections, ovarian cysts and non-viable pregnancies, allowing treatment or culling decisions to be made at an early stage.
A small cost with big benefits
Pregnancy scanning typically costs €3–€5 per cow, plus a modest call-out fee, and usually takes only one to two minutes per animal. The information gathered can influence culling decisions, winter feeding, housing, labour planning and herd fertility for the following year.
Conclusion
Pregnancy scanning is much more than confirming whether a cow is in calf. It is a practical management tool that helps improve reproductive performance, optimise winter feeding, reduce unnecessary costs and support more informed culling decisions. By identifying empty cows early, predicting calving dates and allowing cows to be managed according to their nutritional requirements, pregnancy scanning contributes to a more productive, profitable and efficient suckler enterprise.
Joe Mahon is a B&T Drystock Advisor based in the Teagasc Laois/Kildare/Offaly advisory region.