Feeding ewes in mid-late pregnancy

Mid pregnancy

The period known as mid pregnancy or the second trimester is the second and third months of pregnancy and it is at this time that the majority of placental growth occurs. The placenta is what controls the transfer of nutrients between the ewe and foetus. Therefore, this period you want to ensure that placental growth is optimal in order to reach maximum placental size which will lead to good lamb birth weights and viable healthy lambs.

The key factor in mid pregnancy is not letting ewes lose too much condition; no more than 0.5 body condition score. This can be achieved by well planned grazing. Once sward heights gets below 3cm ewes can either be housed and offered medium quality silage or if conditions allow then silage can be offered outside. Ewes in good condition should be restricted on silage but if the quality is poor then it can be fed ad lib.

At this time pregnancy scanning ewes can be a useful tool to aid in nutritional management. Scanning ewes mid pregnancy will then allow the flock to be split according to litter size, date of lambing and body condition score for late pregnancy feeding.

Late pregnancy

During late pregnancy the ewes nutritional needs rise rapidly as 70% of foetal growth occurs in the last 6 weeks of pregnancy. During this time the udder also develops and the colostrum quality will be largely affected by nutrition during this time. If the fore-milk is pale and thin this indicated poor nutrition in late pregnancy whilst thick, yellow colostrum suggests ewes have been well fed.

In late pregnancy the energy and protein requirements of the ewe carrying twin’s more than double, while her appetite reduces by 30% due to the lambs taking up more space and pushing against the rumen. Therefore increasing the nutrient density of the ration is essential to keep up with foetal growth. Supplementary feeding should be provided to compliment the forage and needs to be gradually increased as lambing gets closer.

Forage quality is especially important in late lambing, with the best quality being retained for use at this time if possible. Ewes will eat approximately 4-5kg/day of fresh, good quality silage but if silage is poor they will reject it. Therefore, keep an eye on rejected material to help predict intake and highlight any problems early. Levels of supplementary feed will depend largely on ewe condition, number of lambs they are carrying and forage quality. It is a good idea to get forage analysed by a reputable laboratory as this will help plan supplementary feeding.

As a guideline, the below table shows a traditional step feeding plan for concentrates over the last eight weeks prior to lambing for a 70kg lowland ewe at BCS 3. This is just a guideline so will need to be adjusted for individual situations.

Weeks before lambing

8

6

4

2

1

Silage (11 MJ/KG DM) 18% CP Compound (kg/day)

Triplets

0

0.2

0.4

0.6

0.8

Twins

0

0

0.3

0.4

0.6

Singles

0

0

0

0.2

0.2

Hay (9 MJ/KG DM) 18-20% CP Compound (kg/day)

Triplets

0.3

0.5

0.7

0.9

1.2

Twins

0.2

0.4

0.6

0.8

0.9

Singles

0

0

0.2

0.3

0.5

Straw (5 to 7 MJ/KG DM) 20% CP Compound (kg/day)

Twins

0.5

0.7

0.8

0.9

1.1

Singles

0.3

0.4

0.5

0.6

0.7

(Source: EBLEX, 2009)