Nutritional requirements of ewes in late pregnancy

IN late pregnancy nutrients are required for the growing foetus or foetuses, ewe maintenance, udder development and the buildup of colostrum.

As 70% of foetal growth occurs during the final six weeks of pregnancy, ewes’ nutritional requirements increase greatly. If scanning has been carried out, group and feed ewes according to their scanning results. It is important that the ewe is managed well during early and mid -pregnancy, as this management will leave the ewe well set up to enter late pregnancy in good condition with a target Body Condition score of 3.

Ewes underfed in late pregnancy produce lambs with low reserves of brown fat used specifically for protection against Hypothermia. Underfeeding can lead to significant problems such as light or weak lambs at birth, higher ewe and lamb mortality, thin ewes, metabolic diseases and lack of colostrum. Twin Lamb Disease and Prolapsed Vagina could also become an issue of underfeeding.

Energy is the main ingredient that needs to be addressed. A 70kg ewe, either dry or in early pregnancy, requires approximately 0.8 UFL for maintenance alone and this requirement increases to 1.37 UFL of net energy in late pregnancy for a ewe carrying twins. Energy levels increase at the time when rumen capacity is reduced.

The ewe’s energy needs can be supplied by a combination of silage plus concentrates. The crude protein requirement for a 70 kg ewe in the last four weeks of gestation is 214g/day.

Crude protein is necessary for udder development which would impact on colostrum supply and milk supply for newborn lambs. A ration with 16 – 18% crude protein is adequate once fed with good quality hay or silage.

There are two main types of protein that are fed to sheep, Rumen Degradable Protein (RDP) is broken down in the rumen. It is required by rumen bacteria to enable them to breakdown forage in the diet. Digestible Undegradable Protein (DUP) is not broken down in the rumen, it is broken down in the gut and its amino acids are absorbed directly from the gut. DUP is essential in late pregnancy for udder development and milk production, e.g. Soya Bean Meal.

Make sure ewes are accustomed to feeding, especially silage before housing. Do not house ewes close to lambing time as ewes do not eat properly for sometime after housing and if near lambing time this could give rise to twin lamb disease. If possible, pen ewes according to their scanning results (singles, twins, triplets) and lambing date which can be calculated if rams were raddled. This will lead to more efficient meal feeding.

On well stocked sheep farms the sheep shed is a critical part of grassland management in ensuring that paddocks closed up in the autumn can remain closed to build up adequate spring grass covers for ewes and lambs at turnout. Ensure ewes have sufficient feed and floor space and a constant supply of clean water.

It is important to get the balance right when feeding silage and concentrates. The higher the DMD the higher the energy content of silage will be. The lower the DMD of silage, a higher concentrate level will be required.

Silage quality will vary greatly in 2018, so getting your silage tested is essential when diets are to be formulated. When high concentrate levels are being fed, care should be taken to introduce meals gradually to avoid acidosis.

The level of supplementation with concentrates will be determined by the number of lambs being carried by the ewe, ewe condition and the quality of the roughage. A mineral mix should be included in the ration at a rate of 2.5% or 25kg per tonne. If silage is of extremely poor quality with a DMD of below 60% or when silage is in short supply, consideration should be given to replacing silage with an all concentrate diet.