Considerations for Feeding Ewes Through Winter
/Winter feeding is crucial for setting ewes up for a successful lambing, with flow-on effects on lamb birth-weight, weaning weight, parasite challenge, and conception rate at next mating. Under-feed, skinny ewes produce less colostrum, have lower milk yield and poorer maternal instinct, their lambs are born lighter and at higher risk. In short, body condition is everything.
Ewes need about 2% of their body weight per day as maintenance, for a 70kg ewe this is 1.4kg DM.
Body Condition Score (BCS)
One BCS unit equates to approximately 10% of liveweight. BCS your ewes as early in mid-pregnancy as practical so that mobs can be identified and preferentially fed.
In early winter if ewes are in good condition (BCS 3–3.5) supplement quality is relatively unimportant. Even poor-quality hay and silage (provided it is not mouldy) are adequate. If ewes are below target condition, highly digestible, energy-dense feeds with moderate protein are needed to allow ewes to regain body tissue and fat.
New Zealand research shows that well-conditioned ewes can even tolerate mild condition loss in early pregnancy if feed is submaintenance, however in mid to late pregnancy where ewe BCS fell by 0.5 units, ewe death rate may nearly double over spring— from 3.5% to 6.4%.
Feeding through pregnancy
In early to mid-pregnancy (up to around day 70), ewe nutrient requirements are basically at maintenance. Feed and supplement quality during this period is pretty unimportant.
From day 70 onwards, requirements increase:
Singles: 1.5–1.8 kg DM/ewe/day; target post-grazing covers of 800 kg DM/ha (approximately 2 cm sward height)
Multiples: target post-grazing covers of 900–1,000 kg DM/ha (2.5–3 cm)
Scanning is a feed budgeting tool.
Three weeks prior to lambing, is critical to lift feed levels and quality of feed for multiple ewes. Offer 2–3 kg DM/ewe/day. Be aware that in late pregnancy, ewes are often physically unable to consume enough to meet their metabolic demands, so highly digestible, high-carbohydrate feeds are important at this stage to reduce the risk of pregnancy toxaemia (sleepy sickness). With the prices for lamb and ewes currently, there is a strong case for feeding extra supplements such as sheep nuts or barley – soya mixes. Kale and green feed hybrid grasses are ideal.
A note on protein
A 2024 AgResearch study across eight South Island sheep and beef farms compared productivity in ewes fed fodder beet (9% protein) versus a control brassica diet (kale or swedes). Ewes in the fodder beet group that received no protein supplementation had approximately 40% fewer lambs per ewe mated. When ewes were supplemented with lucerne hay, soy meal, and urea to achieve 18% protein in late pregnancy and maintain BCS, farm productivity was restored.
Fodder beet systems in this study cost 63–86% of comparable brassica systems. Targeted protein supplementation approximately doubled feed cost per hectare — though in the study their use still resulted in an economic surplus. The cost of not supplementing was BCS loss, increased lamb mortality, and a 10% reduction in overall farm productivity.
Winter to-do list
BCS ewes in mid-pregnancy — the earlier the better, so lighter mobs can be identified and preferentially fed
Identify your best lambing paddocks early and graze them out so covers can build for set stocking
Match supplement type and quality to ewe condition and stage of pregnancy
Plan protein supplementation if ewes are on low-protein crops (e.g. fodder beet) in late pregnancy
