Outwintering livestock on brassica and forage crops

Outwintering can be a great alternative to housing, with many animals maintaining good condition and liveweight gain. However, it requires careful stockmanship and animal management.

Outwintering is the rearing of livestock outside through the winter months. This typically involves grazing the livestock on forages or brassicas such as:

• Fodder beet
• Kale
• Swedes
• Stubble turnips
• Deferred grazing (all-grass wintering)

Outwintering can achieve the same performance and health as housed animals but requires careful management and planning. Feed costs can be 20–30% lower than that of housed animals. AHDB research found that there is typically more variation in performance between farms due to management rather than the forage choice.

Benefits include:

• Livestock can achieve the same performance as if they were housed
• Purchased feed costs can be reduced by increasing the use of home-grown feed
• Forage crops can be high yielding
• Reduced reliance on conserved forage through the winter
• Reduced pressure on buildings over winter

Drawbacks to be aware of:

• Not a ‘low labour’ system
• Requires careful management and planning (e.g. feed budgeting and wet weather strategy)
• Requires close monitoring of animal health and welfare
• Can have poor public perception

• Gently sloping with sandy soil and good drainage
• Shelter for livestock (with good airflow to allow fields to dry out)
• Away from watercourses
• Grass buffer strips around the field to reduce water run-off
• Moveable water supply to allow a back fence
• Good access, with tracks or stone in gateways
• Well-fenced
• Grass run-back, headland area or straw bed as a dry lying area
• Site used as part of a planned crop rotation

Monitor targets by weighing and body condition scoring every 2–4 weeks. Any animals that are underperforming should be managed in a separate group or housed.

Offer a fresh break of crop daily. Strip grazing provides the most efficient utilisation and prevents trampling and waste.

Monitor crop cover on a weekly basis using a quadrant, harvesting a sample, removing the soil and weighing. Allocate feed assuming 85% utilisation. 

Monitor feed budget monthly to ensure nutrition and feed allowance is appropriate for livestock age, growth, winter conditions and stage of production. Heifers may require over 1 kg DM/animal/day additional allocation (or + 10–20% feed).

Monitor animal health and have a risk strategy for poor weather so that animals remain comfortable and have access to adequate food and water.

Other points to consider:

• Grass silage or hay intake should be 35% of total DM when feeding
• Ensure the feed face and run-back (or dry lying area) can accommodate all animals at the same time. Aim for 2 m² per head for cattle
• Choose the forage crop based on field soil type and potential crop yield
• Have a 10–15-day transition period and start by running animals onto the crop on full stomachs a couple of hours a day
• Space out feeders and regularly move to prevent poaching and feed contamination
• Start grazing from the top of a slope as this can reduce P loss by 80% and soil and nitrogen loss by 90%
• Back fence every 4–5 days

Growing cattle outwintered on brassicas can achieve growth rates of 0.6–0.9 kg per day. Good growth rates depend on feeding good quality hay or silage with the brassicas.

SAC research showed compensatory growth could be achieved cheaply at grass following the outwintering period. This resulted in similar weights being achieved compared (at the end of the following summer) to cattle reared indoors.

Feed costs and performance of weaned suckled steers (2005/2006, SAC)

Calculation assumptions: based on 30:70 fibre to brassica ratio. Daily dry matter requirement is assumed to be 3% of BW. Therefore, a 300 kg steer would require approximately 3 kg of straw or silage. Silage at £45/tonne and straw at £50/tonne. Five-month wintering period. Sources: Cattle Out-wintering Systems. SAC Consulting. The Farm Management Handbook 2015/16. *Includes forage crop, fibre source, labour and machinery.

In an AHDB study for outwintering dairy bred beef cattle on fodder beet:

Trials at SAC also demonstrated that under appropriate field conditions, non-lactating, spring-calving suckler cows can be outwintered on kale and stubble turnip systems, with no concerns in relation to liveweight or condition loss. Free-draining sites with good dry lying areas, electric fencing that could be easily moved each day and good stockmanship are all vital for the system to be successful.

Relative costs and response of dry spring-calving suckler cows outwintered on brassicas (based on SAC, 2005)

Calculation assumptions: 180-day outwintering period, 5 kg/head/day straw allowance. Silage/deferred grazing needs 10 kg DM/head/day based on a 650 kg cow requiring 1.5% bodyweight DM intake. Grass assumed at 6p/kg/DM for 60 days deferred grazing. Silage assumed at 13p/kg/DM for 120 days silage. Housing – cattle need an additional bedding/straw allowance of 2 kg/head/day. Feed concentrates at 3 kg/head/day assumed at £240/tonne. Silage area requirement 0.1ha/head at £213/ha. Sources: Cattle Out-wintering Systems, SAC Consulting, The Farm Management Handbook 2015/16.

Consult your vet about the risks of outwintering and modify your health plan according to crop choices. Vaccinate wherever possible, and use bolus for mineral deficiencies. Potential issues are provided in more detail on the Health and welfare considerations for grazing brassica and forage crops page.

You should:

• Ensure animals are in good body condition before outwintering
• Manage any animals in poor condition in a separate group or house
• Feed a long fibre forage source such as baled grass silage to help prevent rumen acidosis or bloat
• Be adaptive to changing weather conditions, crop yield and quality, and alter stocking rates suitably and have a contingency plan in place
• Ensure animals always have access to adequate clean water. Consider portable water troughs
• Not outwinter sheep within two months of shearing
• Discuss mineral supplementation with your vet and nutritionist, depending on your crop and forage choice iodine and copper may be required
• Consider a clostridial vaccination

AHDB research has shown no negative effects of outwintering on the health, fertility, milk yield or somatic cell count of first lactation dairy heifers. Remember, though, that this does require careful planning and management.

Only healthy animals in good body condition should be considered for outwintering. Do not outwinter old or thin animals. Any animals that are thin, lame or will not eat the crop should be managed separately or housed.

Consider moving animals off crop for the last few weeks before marketing or calving/lambing, so animals are clean. It is not recommended to calve or lamb animals during outwintering. Breeding animals in late pregnancy may need additional protein to ensure their feed requirements are met.

Introduce stock to the forage or brassica crop slowly on full stomachs to avoid digestive upsets. Ideally, start by allowing the stock access to the crop for 1–2 hours a day, building up to unrestricted access after 7–10 days.

Cattle can lose weight in the first weeks of grazing before growth rates are established, but a gradual introduction to the crop reduces the risk of weight loss. Good growth rates depend on feeding good quality forage with the crop. Silage or good quality hay would be better than straw.

If you would like to order a hard copy of Using brassicas for Better Returns please contact publications@ahdb.org.uk or call 0247 799 0069.