Have sight, smell or sound of prior to teaser introduction’
If the ewe is expecting singles, this quantity can be reduced by half. The farmer must ensure adequate trough space is available — approximately 60cm for large ewes (90kg).
The nutrient requirements of the ewe to include energy, protein and calcium, double in the last two months of gestation. In late pregnancy, the development of the mammary glands and the production of colostrum require extra energy on the part of the ewe. In addition, approximately 75-85pc of lamb foetal growth occurs in the final eight weeks of gestation. However, the extra space occupied by the growing foetus decreases the rumen size and reduces her intake capacity by approximately 33pc and so the diet of the ewe is restricted. In the case of multiple births, the situation is worsened.
Roughage alone will not satisfy the needs of the ewe in terms of energy and so concentrates must be introduced, and the quality of these is crucial in meeting the nutrient requirements of the pregnant animal. In addition, key to deciding the amount of concentrates to be fed is the quality of the silage. Average quality silage should provide just enough energy to maintain an 80kg ewe. Higher quality silage should allow for less concentrate supplementation due to a higher energy intake. In addition, precision chop silage is the way forward in terms of maximising the ewe’s ability to digest the fibre content and testing the silage quality will prove beneficial to the sheep farmer long term. Once the farmer has assessed his/her own situation, the level of concentrates can be decided. Both the energy content and the protein content of the ration is important — 110g/CP/ewe/day and 12 MJ ME* at 6 weeks should suffice, increased to 200g/CP/ewe/day and 18 MJ ME just before lambing.
It is worth noting that feeding concentrates causes a decrease in the rumen pH, which negatively impacts the various micro-organisms present. It is these micro-organisms that are responsible for the digestion of cellulose, the main component of silage. The less present, the longer it takes to digest the forage especially if it is of poor quality.
So when feeding concentrates, it is recommended to do so over the course of the day, rather than one single feed (no more than 500g in a single feed, more than 500g split into two feeds, with 1kg spread over three feeds).
A vitamin/mineral supplement is also recommended with recent research indicating that Vitamin E in the diet of the pregnant ewe can result in the new born lamb being able to stand quicker and suckle. Lack of selenium in the diet of the pregnant ewe has been linked to low energy reserves in the lamb at birth.
All-concentrate feeding of ewes works well in relation to animal nutrition and performance but cost and expense of such a diet may be the deciding factor for the sheep farmer.
* CP: crude protein MJ: mega joules ME = metabolisable energy