Appropriate nutrition and management during late pregnancy is key to profitable mid-season lamb production. 75-80% of foetal growth occurs in the final six-to-eight weeks before lambing.
The rapid growth of the foetus increases the ewe's need for nutrients; and daily requirements can no longer be met by a forage-based diet alone.
The level of concentrate feeding to ewes will be determined by the quality of your silage. By having a silage analysis report, it will allow you to make management decisions on the levels of concentrate supplementation in late pregnancy.
Four factors will determine the amount of concentrates which should be fed to ewes during late pregnancy. These include: the number of lambs being carried by the ewe; the stage of pregnancy - number of weeks before lambing; the body condition score (BCS) of the ewe; and the quality of the hay, silage or other forages being fed.
When feeding concentrates to ewes in late pregnancy, consider the following:
- Watch ingredient specifications closely - don't skimp on cost;
- Ideally, feed 17-20% crude protein;
- Use high-quality protein sources to enhance milk output on both grass and preserved forages. Soybean meal is an excellent quality protein source;
- Feed a ewe nut with optimum levels of cereals (barley, wheat, maize) in order to maximise energy intakes;
- Ensure that the vitamins and mineral mix are suitable, e.g. calcium and magnesium (Cal-mag) included in order to reduce the risk of milk fever and grass tetany post-lambing;
- Introduce concentrates at a low level and build up slowly.
There are a number of other management factors which impact the nutrition of the ewe in late pregnancy.
Water: It is vitally important that a fresh clean supply of water is available to pregnant ewes at all times. A pregnant ewe will consume up to 6L of water per day where the feed being eaten is high in dry matter and especially on an all concentrate diet.
Water troughs should be checked regularly and cleaned out if contaminated with faeces, hay or silage.
Trough space: Where concentrates are being fed, it is vital to ensure that adequate trough space is provided. For a standard bay, 4.8m wide, there is not enough space to feed greater than 10 ewes - each of 70kg in late pregnancy. Trough space requirements of different size ewes are outlined (below).
- Ewes must be correctly fed in late pregnancy in order to provide for the growing foetus and to ensure the ewe herself is prepared for the lactation period;
- Where silage or hay is being fed, supplementation with concentrates will be required. This will be determined by the number of lambs being carried, the BCS of the ewe and the quality of the silage or hay being fed;
- Where silage is of poor quality (<60% DMD) or if silage is in short supply, consideration should be given to an all concentrate diet. Care should be taken, however, to build up concentrates gradually to avoid digestive upsets;
- Adequate trough space and a fresh supply of clean water are vitally important.