Feeding ewes over winter
Having ewes in good body condition in the autumn, means that body condition can be more easily maintained over the winter without compromising production the following spring.
In winter the main two considerations are:
- Allocating feed so available feed (including
supplements) meets animal demand until the spring flush.
- Maintaining a ewe body condition score of three until lambing (especially in last four to six weeks) and avoid under or over-feeding to reduce the risk of sleepy sickness, milk fever or bearings prior to lambing.
Feed budgeting will predict feed deficits (or surpluses) in advance which in turn will allow you to respond by means of feed conservation or purchase of more feed, cropping or nitrogen application. In doing this, solutions to match your feed supply with animal demand can be found. The aim of a feed budget is to maintain pasture covers, say within 1000-2500kg DM/ha so that ideal pasture quality, and hence optimal animal performance, is achieved.
Energy requirements in the first 100 days of pregnancy are similar to that of a dry ewe being fed to maintenance. Now is a good time to be identifying lighter body conditioned ewes (especially those carrying multiples) and prioritising their feeding. The lighter ewes will need to be shifted before post-grazing covers drop below 1000kg DM/ha (2cm sward height).
Over winter aim to have the ewe flock going onto pre-grazing pasture covers of 1000-1200kg DM/ha (minimum 2-3cm sward height) and leaving post-grazing covers of around 800kg DM/ha. It is important however that you limit the time that ewes are grazing below 800kg DM/ha (1cm sward height). This will also allow pastures to recover in time for the next grazing.
Ewes can be restricted to a maintenance diet (or lower for short spells) until later in pregnancy. If there is a need to save feed for late pregnancy, ewes can be fed sub-maintenance until four to six weeks prior to lambing. Up to a nine kilogram loss (unless ewes are already light) can be tolerated without detrimental effects on ewe survival, barrenness, twinning rate, lamb birth weight, lamb survival, ewe milk yields and weaning weights. However, ewes (especially those carrying multiples) must not lose body condition 35 days out from lambing.
About 80% of lamb growth occurs in the last 50 days and hence the ewe's energy requirements increase by 150-200% of maintenance requirements at this time. However, in reality, ewes in late pregnancy will seldom be able to eat enough to meet their total requirements. Some degree of under-nutrition at this stage can be tolerated without lowering birth weights, but sudden restrictions must be avoided. Provision of high quality feed is essential during this time.
Normal practice is to set stock ewes one to two weeks before lambing but, where pasture covers and growth rates are low, it is better to wait as long as possible before set stocking the ewes. This will avoid ewes with lambs at foot running out of feed in the first month when the ewe's feed requirements are at their peak.
If you have questions or would like further advice then give your vet a call.