Pregnancy and Lactation Requirements

It’s crucial pregnancy and lactation nutritional requirements are met to achieve high targets at lamb marking and weaning.

If energy requirements are met a ewe will be able to maintain her current condition score. As ewe’s move through gestation the requirements increase considerably through to lambing. If you are meeting these daily energy requirements and hitting condition score targets, it is likely you will be able to achieve a successful lambing result. If condition score (CS) targets are met ewe mortality over the lambing period is also likely to be reduced.

As ewes are progressing through gestation lamb development requires the correct nutrition. The placenta is developing during the first trimester which can have an impact on nutrients available to the foetus and final lamb size at birth. The primary and secondary wool follicles are also being formed on the foetus – inadequate nutrition can reduce wool density and clean fleece weight for that animal for the rest of its life reducing the value of ewe lambs in a self-replacing enterprise.

Adequate nutrition, which includes meeting energy targets but also having adequate protein during the last trimester of pregnancy, will ensure adequate foetal growth. Reaching birthweight targets will give the best opportunity for lambs to survive and thrive after birth. Larger lambs have more fat cover which gives them a better chance of survival in the 48 hours post birth, especially if they are exposed to inclement weather.

When determining energy requirements for a ewe during gestation it is critical to know the pregnancy status of the ewe and manage her accordingly. A twin bearing ewe requires much more energy than a single bearing ewe and feeding her correctly will mean birthweight of the twin bearing lambs is likely to be optimised to improve survival. This will ensure a high marking percentage can be achieved in the twin mob. Without knowing pregnancy status, it becomes difficult to select correct paddocks and feed ewe mobs correctly.

Once energy requirements have been identified for the ewes through pregnancy and lactation it’s important to assess if the available pasture is likely to meet these requirements. If not, its crucial to identify the best and most cost-effective methods of supplementary feeding stock.

Hay quality has been quite good this year in most area’s which has enabled producers to supply more of the required energy with hay. However once twin bearing ewes get closer to lambing, they have less gut space so more energy dense supplementary feeds, such as cereal grains or full feed pellets can supply more energy and be more effective as part of the ration. High quality, high protein hay like vetch and lucerne can be an effective method of supplementing lactating ewes (in conjunction with pasture or cereal hay or grain). However, a high protein (and unbalanced) ration prior to lambing can lead to excessive foetal growth and large lambs which may cause difficulties over lambing.

Lactating ewes have a very high energy requirement, a 60kg lactating ewe with twins will require up to 30MJ of energy per day during peak lactation, 20 – 30 days after lambing. Ewes may drop some condition over lactation, provided lambs are weaned in a timely manner and the ewe has plenty of time to put condition back on before the next joining.

When determining the correct balance of pasture or supplementary feed it’s important to determine you’ve met the ewe’s energy, protein and fibre requirements to ensure you have a successful lambing and lactation period and give the lambs the best opportunity to thrive through to weaning.