Supplying adequate amounts of protein in the diet of ewes in late pregnancy is vital, and must be considered for a number of reasons.
Nutrition during late gestation influences a ewe’s body reserve mobilisation, colostrum production, lamb birth weight, lamb vigour and lamb survival.
Late pregnancy is generally defined as the last six to eight weeks before lambing. During this time, a substantial amount of foetal growth takes place and getting diets right is a difficult task, due to the rapid growth of the foetus.
The developing foetus reduces the feed intake potential of the ewe and essentially leads to the need for concentrates to be introduced.
With many mid-season flocks edging closer to lambing this coming month, for the final two to three weeks of pregnancy, rumen undegradeable protein or by-pass protein is particularly important in the diet of ewes.
It supports mammary gland development and the process of colostrum production. Soybean meal is an excellent source of rumen undegradable protein and has been shown in the past, according to Teagasc, to improve subsequent lamb performance.
It is important that rations offered to ewes during this late stage of pregnancy contain a high percentage of soybean meal or that additional soybean meal is offered with the ration.
It is recommended to feed 100g of soya/scanned lamb in the final two, to three weeks of pregnancy.
Ideally, farmers should be looking to feed a ration with a crude protein content of 18-20%, especially if silage or hay quality is poor, and to ensure that soybean meal accounts for a high proportion of the protein present within the concentrate.