Nutrition during late gestation influences ewe 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, so getting diets right during this time is a difficult task, due to the rapid growth of the foetus – which reduces the feed intake potential of the ewe and essentially leads to the need for concentrates to be introduced.
Also Read: ‘Surprising number of farmers feeding low energy rations’For the final two-to-three weeks of pregnancy, rumen undegradable 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 per 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.