The Complete Guide to Lambing Season in the UK

Lambing season is the busiest and most important time of year on any sheep farm. With most UK flocks lambing between January and April, the weeks of preparation beforehand can make or break your results.

Research shows that 25% of a sheep farm’s annual workload occurs during the lambing period, so getting your preparation right is essential.

This guide brings together everything you need to know, from understanding sheep gestation and pregnancy scanning, to preparing your lambing shed, stocking up on lambing essentials, and using technology like the Herdwatch app to keep on top of records. Whether you’re a seasoned sheep farmer or preparing for lambing for the first time, these practical tips will help you achieve a productive lambing season.

When Is Lambing Season in the UK?

Lambing season in the UK typically runs from January through to April – this is the lamb season when baby lambs arrive on farms across the country. The exact timing depends on your farming system, location, and breeding strategy. Hill flocks tend to lamb later (March–April) to coincide with better weather and grass growth, while lowland flocks often start lambing as early as January or February.

Pedigree flocks using artificial insemination (AI) or embryo transfer (ET) may begin even earlier.
The lambing period is determined by when rams were introduced to the flock. Sheep gestation lasts approximately 147 days (around 5 months), so if rams go in during October, you can expect lambs to arrive from mid-March.

Understanding your lambing calendar is the first step to effective preparation. Knowing when lambing season starts – and when it ends – allows you to plan nutrition, scanning, housing, and staffing well in advance.

Sheep Pregnancy Scanning: When to Scan and Why It Matters

Sheep scanning is one of the most valuable management tools available to any sheep farmer. A trained professional uses an ultrasound scanner (sometimes called a sheep pregnancy scanner) to determine whether each ewe is pregnant, how many lambs she is carrying, and to identify barren ewes that can be separated from the flock.

When to Scan Ewes

The best time to scan ewes is 80–100 days after the rams have been removed from the flock. Scanning ewes earlier or later than this window may give inaccurate results. Getting the timing right when scanning ewes for pregnancy is crucial for reliable records.

Why Scanning Improves Lambing Percentage

Ultrasound scanning helps you improve lamb survival rates by allowing you to draft ewes immediately after scanning into groups based on litter size. Twin-bearing ewes should be further separated into heavy or light body condition groups to ensure they receive the right level of nutrition heading into the final weeks of pregnancy.

Your target scanning percentage should be based on your system:

• Hill flock: 100–120%
• Upland flock: 120–170%
• Lowland flock: 170–200%

Factors such as weather, grass growth, and ewe body condition score can all affect your final lambing percentage. Recording and reviewing scan results year on year helps you make better breeding and culling decisions.

Recording Scan Results with Herdwatch

With the Herdwatch app, you can add pregnancy scan results straight into the app on scanning day. Record the number of lambs due, sire details, and whether a ewe is empty or pregnant. This data feeds into your Due to Lamb list, making it easy to plan feeding groups and monitor ewes as they approach their lambing date.

Pre-Lambing

Ewe Nutrition in Late Pregnancy

Pre-lambing nutrition is critical. Around 70% of lamb growth occurs in the final six weeks of sheep pregnancy, so feeding levels during this period directly affect lamb birth weights, ewe milk production, and overall lamb survival. Underfeeding can lead to higher lamb mortalities, twin lamb disease, and poor colostrum quality.

Introduce concentrates into the ewes’ diet in late pregnancy to compensate for any shortfall in forage quality, particularly during adverse weather. Feed containing high energy and a quality protein source promotes milk production, while vitamin E improves colostrum quality and lamb survival rates.

Body Condition Scoring in Ewes

Assess the body condition score of your ewes well before lambing. Ewes in poor condition are less likely to produce adequate milk and colostrum, and are more susceptible to metabolic diseases. Ideally, ewes should be at a condition score of 3.0–3.5 at lambing time. Thin ewes should be separated and given preferential feeding.

Vaccinations, Foot Care and Health Checks

Ensure your ewes are up to date with vaccinations and worming treatments before lambing begins. Check for lameness – a lame ewe during gestation is less likely to get up and feed, which can cause loss of condition, twin lamb disease, reduced milk production, and smaller lambs. Ewes that are lame after lambing are likely to rear weaker lambs as they spend more time lying down, preventing their lambs from suckling.

If lambing indoors, ensure there is plenty of fresh bedding and spread powdered lime beneath fresh straw in high footfall areas. If outdoors, check ewes’ feet for dried mud between the claws and treat any conditions promptly.

Lambing Checklist

Being organised and having all your lambing supplies on hand before the season starts takes the pressure off during those long days and nights. Carry out a stock-take well before your lambing start date and make sure you can tick off every item on this lambing equipment list:

Lambing Essentials

• Iodine (7% concentration for disinfecting navels)
• Lubricant (veterinary-approved, non-toxic)
• Lambing gloves and plastic sleeves
• Lambing ropes
• Syringes, needles, and drenches
• Clean towels
• Uterine boluses
• Halters

Feeding Supplies

• Powdered/artificial colostrum
• Ewe milk replacer (lamb milk replacer)
• Feeding bottles and teats
• Stomach tube
• Jug and whisk for mixing
• Drinkers and feeders

Lamb Care & Marking

• Lambing heat lamps and bulbs (or heat box for weaker lambs)
• Castration rings and applicator
• Marker spray
• EID tags or ear markers

Health & Hygiene

• Calcium injection
• Twin lamb supplement
• Lime / disinfectant for lambing pens and high footfall areas
• Medicine cabinet – check all stock is within date
• Technology
• Lambing cameras for remote monitoring
• Herdwatch app – loaded with remedies in your cabinet

If you’re wondering where to buy supplies for lambing season, most agricultural merchants stock everything on this list. Order early to avoid shortages during peak demand.

Setting Up Your Lambing Shed and Lambing Pens

How Many Lambing Pens Do You Need?

Adequate lambing pens – in both size and quantity – are key. Aim for 1 lambing pen for every 10 ewes. For example, a flock of 200 ewes should have a minimum of 20 sheep lambing pens. Each lambing pen should be roughly 1.5m x 1.5m to give the ewe and her lambs enough space to bond before moving to a group pen or outdoors.

Lambing Shed Layout Tips

Think about your lambing shed layout before the season begins. Group ewes according to scanning results (singles, twins, triplets) and have an ‘extra care’ pen available for unexpected events such as triplet lambings. Ensure hay racks, water sources, and meal containers are set up in each pen. Good lighting is essential, especially if you plan to work during the night.

Lambing Pen Hygiene

Good hygiene is critical at lambing time. Clean out every pen between use and disinfect with powdered lime or another suitable disinfectant. Keep bedding clean and dry. Avoid housing sick ewes alongside healthy ones to minimise disease transfer.

Additional hygiene tips:

• Change gloves for every new lambing to avoid mixing lamb scents (which can cause ewes to reject their lambs)
• Disinfect equipment such as ropes between use
• Clean feeding bottles and teats immediately after use in hot water and soap
• Provide clean, fresh water to ewes and lambs at all times
• Keep your own clothing and boots clean – change if soiled after lambing

Colostrum is Liquid Gold for Newborn Lambs

Colostrum is the single most important factor in newborn lamb survival. It provides passive immunity, essential nutrition, and vital antibodies to help prevent disease in the first days of life.

How Much Colostrum Does a Newborn Lamb Need?

Lambs require 50ml per kg of bodyweight per feed, totalling 200ml per kg in the first 24 hours. For example, a 5kg lamb needs approximately 250ml of colostrum every 6 hours. It is vital that every lamb receives colostrum within the first 6 hours of being born, as the lamb’s ability to absorb immunoglobulins into its bloodstream decreases rapidly after this point.

Colostrum Handling and Storage

While artificial or powdered colostrum is available as a backup, aim to use the dam’s own milk where possible. The next best option is stored ewe’s milk from your own flock, which avoids the risk of disease transfer between flocks.

Key storage guidelines:

• Fresh colostrum: stores for up to 6 weeks in a fridge
• Frozen colostrum: stores for up to 6 months in a freezer
• Source from your own flock where possible
• Store in sealable colostrum bags, laid flat for easy thawing
• Thaw frozen colostrum slowly to body temperature – heat above 40°C will destroy vital proteins and immunological components

Colostrum can be collected from ewes with single lambs (who will have surplus) or from dams who have lost their lambs. If the ewe cannot supply enough, you can top up with cow’s colostrum, powdered colostrum, or ewe milk replacer.

During Lambing

Signs a Sheep Is About to Give Birth

Knowing the signs that a ewe is close to lambing helps you intervene at the right time. Look for restlessness, pawing at the ground, separating from the flock, a swollen vulva, and the appearance of the water bag. Most ewes will lamb without assistance, but be prepared to help during lambing season if labour is prolonged or the lamb is malpresented.

How Long Should a Sheep Be in Labour?

How long should a sheep be in labour? Once active straining begins, a ewe should deliver within 1–2 hours. If she has been straining for more than an hour without progress, it may be time to investigate and assist.

Always have your vet’s contact details to hand for emergencies.

How to Record Lambing on Herdwatch

• The Herdwatch app makes record-keeping during lambing fast and straightforward, even in the middle of the night. Here’s how to create a lambing record:
• Tap the orange plus button (+)
• Tap on ‘Lambing Record’ or search for it
• Select the ewe who has lambed
• Fill in the required details: date of birth, lambing number, how many lambs, and any complications
• Tap Next to record details for each lamb – gender, tag number (or lambing number if not yet tagged), and birth weight
• Press Save

Herdwatch also lets you create groups and smart lists straight from the app, so you always know who’s who in your flock. You can record weights to monitor lamb growth rates, review breeding records to make informed culling decisions, and use the culling tool to highlight problematic ewes.

Having all your treatments pre-loaded in the app’s medicine cabinet before lambing starts means you’re more likely to stay on top of record-keeping and achieve excellent reports for any farm inspection or audit. Other workers on the farm can check past treatments within an animal’s profile and keep on top of treatment plans.

After Lambing

Once lambing season ends, take the time to review your results. Calculate your lambing percentage and compare it to your scanning results. Use Herdwatch to review breeding records, identify ewes that consistently underperform, and make informed decisions about culling and your breeding strategy for next season.

A good post-lambing review covers lamb survival rates, colostrum management, any disease issues, and how well your lambing shed layout and pen numbers worked. This is also the time to think about your farming calendar for the months ahead – shearing season, weaning, and planning when to reintroduce rams.

Simplify Your Lambing Season with Herdwatch

From pregnancy scanning through to recording every birth, Herdwatch takes the paperwork out of lambing and puts everything at your fingertips. Join over 20,000 farmers worldwide who are already using Herdwatch to streamline their sheep and farm management.

Download the free Herdwatch app today from the App Store or Google Play or sign up for your 30-day free trial.