Ewe nutrition requirements through the production year

Getting ewe nutrition right is not only critical to the health of the ewe and her lambs, both present and future, it is also pivotal when it comes to profitability.

Nerys Wright, knowledge exchange manager for AHDB Beef & Lamb says sheep liked a steady, consistent feed and it was important to keep the rumen pH stable.

“Our job is to feed the bugs that live in the rumen and those bugs will feed the sheep for us.”

See also: Advice on flushing ewes with a low body condition score

There are key times throughout the production year when it is important to check body condition score (BCS) and adjust diet accordingly to keep the ewe at optimum condition to produce and wean a strong lamb:

Tupping

Target BCS: 3.5 for lowland, 3 for upland and 2.5 for hill

“It is important to say that this [BCS target] is not a flock average, it is an individual ewe target,” Ms Wright says.

BCS needs to be checked before tupping to aim for these targets. It doesn’t matter whether scoring is done with full EID or by syphoning ewes off into different groups to feed them accordingly, but the important factor is putting a hand on the animal.

It takes six to eight weeks to gain one unit of condition, so it is too late at tupping time to realise they are not at the right score.

Ms Wright says it would appear that while you can regain condition fairly quickly, you cannot undo the damage of falling behind on BCS because the follicles are set a long time before mating. Therefore, nutrition requirements need to be determined at weaning (see below).

“Take care with flushing and definitely do not hold them back to flush them. It should be a back-up plan,” Ms Wright advises. “We know it has little effect if the ewe is already in good condition.”

Mid-pregnancy

Target BCS: 3.5 for lowland, 3 for upland and 2.5 for hill

It is key to maintain diet throughout this time, avoiding any sudden changes.

Maintaining body condition scores and weight up to scanning will have a positive effect. Up to BCS 4, we see a linear curve of benefit. At BCS 4 and above, scanning results will drop off.

Late pregnancy

This is when 75% of foetal growth takes place. Nutrition is key to support the ewe’s immune system, udder development and colostrum production.

Nutrition in late pregnancy will determine what the ewe can produce in lactation.

Pre-lambing checks

Approximately three weeks before lambing is a good time to seek veterinary advice on blood sampling ewes (ideally twin- and triplet-bearing) for:

• BHB – this shows if the body is mobilising fat to meet energy needs
• Urea – shows a same-day protein deficiency
• Albumin – long-term indicator of protein levels

Any deficiencies require the feeding plan to be assessed. It isn’t a case of just adding concentrate: the overall ration should be analysed.

Lambing and lactation

Target lambing BCS: 3 for lowland, 2.5 for upland and 2 for hill

Ewe demand doubles almost immediately when they have lambed, so if they are housed they should have ad-lib food to ensure they don’t run out, alongside plenty of water.

They reach peak milk yield at 3-4 weeks after birth, so attention is needed in this window.

In years where grass growth is slow or if it’s really wet, ewes will fill up on water so it is important to look at where help is needed in the four weeks after lambing.

Ewes can milk off their back if body condition score is there, but if it is not and food is not either, it will affect lamb growth.

See also: 8 ways livestock farmers can manage a grass shortage

Eight weeks post-lambing

Target BCS: No more than 0.5 loss since lambing

Target lamb weight: 20kg

This is a good time to check ewe condition and lamb weights to determine weaning date.

While the recommendation is to wean at 90 days (just over 12 weeks), with flexibility for circumstances such as ewe lambs and thin ewes, Ms Wright said many people were still weaning at 14 to 16 weeks and this could affect the subsequent lambing.

“There needs to come a point when you wean to focus on lamb growth and ewe condition for the next tupping.”

Weaning

Ewes should be grouped by BCS at weaning so that feed can be adjusted accordingly to get them in the right condition for tupping.

Nerys Wright was speaking at a National Sheep Association webinar.