Advice for flushing ewes with low body condition score

Sheep farmers are advised to assess ewe body condition now and act to rectify any with a score lower than 3, after initial results from AHDB project flocks revealed a higher proportion of ewes are lean following this summer’s grass shortage.

Body condition score (BCS) at tupping should be 3, but results from two AHDB RamCompare flocks, each made up of 300 commercial ewes, show:

• 55% of ewes at one farm have a BCS of 2 or less
• 41% of ewes at the other farm score 2 or less
• 18% of ewes at both farms score 2.5.

See also: How technology is helping farmers curb sheep thefts

Why body condition is important

Correct body condition at tupping is important for fertility, with ovulation rates reduced by 0.45 for every one unit in BCS.

AHDB Beef and Lamb senior scientist Liz Genever says ewes with a BCS of 2 or less will require a “significant amount” of feed to get them back up to a score of 3 for tupping.

Feeding requirements

A 70kg lowland ewe has a daily energy requirement of 8.4MJ for maintenance, which they will achieve by eating a minimum of 1kg of dry matter (DM) a day of poor-quality grass or hay.

However, ewes will need an additional 3.5MJ a day to put on 0.5 BCS. For example, a ewe with a BCS of 2 will require an extra 7MJ daily, which can be achieved by feeding 150-200g of 12ME barley, she adds.

This is when extra forage or concentrates will need to be fed (see “Example energy and dry matter intake of lowland and hill type ewe of different starting body condition scores to gain required condition between weaning and mating”, below).

Careful grazing management may be required to help ensure BCS targets are hit. The AHDB suggests rotational grazing as a method for managing grazing more effectively.

Flushing – is it good practice?

Although flushing by feeding a high plane of nutrition just before mating was traditionally applied to all sheep, it is actually only a short-term fix when ewes fail to reach their target body condition for mating, explains Dr Genever.

“Ensuring ewes are the correct BCS at mating is the priority, with flushing being a secondary tool for those that fail to hit the targets.

“Ewes in the correct condition have good ovulation rates that will not be improved by a further rise in the level of nutrition.”

Dr Genever says ewes receiving supplementary feed should be checked after a month.

“In this time [providing they are on the correct nutrition] they should have gained half a condition score.

 “If your ewes fail to hit BCS targets after supplementary feeding then it is worth investigating if there are any underlying causes, such as poor teeth,” she advises.

Rams

Dr Genever also urges farmers not to forget about ram condition.

Rams need to be BCS 3.5-4 at mating. Although results from RamCompare have found only one or two rams out of 25 with possible fertility problems, condition may still be an issue given the grass shortage.  

“Give your rams an MoT and check what is going on. If they are slightly under condition you might need to up the protein in the feed, as this helps testicle tone. If everything is fine then you don’t need to feed anything else,” she adds.