Ewe condition key driver of lifetime performance

The way we feed ewes, expressed through body condition score (BCS), has a much longer-term influence on ewe lifetime performance than previously thought. This was one of the main findings presented by Lesley Stubbings, UK sheep consultant (LSSC Ltd) at this week’s Teagasc lowland sheep conferences.

It has long been documented that nutrition influences ewe and lamb performance at all stages of production.

There was a train of thought however that addressing the condition of ewes falling below target would essentially reset their production potential.

However, this is far from being the case, with Lesley highlighting that inadequate condition score will have a negative effect on subsequent litter size and lamb performance with ewes never realising their true lifetime production potential.

The findings presented were backed up by two sets of data. Lesley first highlighted an Australian project called Litetimewool – now using body condition score as the basis of flock management.

Significant improvement in flock productivity has been achieved on farms through addressing ewe condition and minimising ewe weight loss.

Closer to home, the Agriculture and Horticulture Development Board, better known as AHDB, set up a project on three English farms covering 3,000 ewes in 2012/13 to look at the effects of BCS on performance and to establish if key performance indicators could be developed for commercial sheep farms.

Electronic identification (EID) was outlined as a major aid to the study facilitating relatively easy and quick capture of data. While EID presents a cost to the sheep industry, where used to full potential it can deliver a worthwhile return on investment. A comprehensive recording programme was put in place and looked at ewe BCS at weaning (90 days post-lambing), pre-mating, scanning (including ram removal on one farm), pre-lambing (with some also assessed at four to six weeks of lactation) and 56 days post-lambing.

Preliminary findings

The project is still ongoing, but Lesley says preliminary findings are unearthing some very interesting and useful information. BCS changes in the period from weaning to scanning not only affect litter size, it also has a marked influence on 56-day lamb weights as demonstrated in Figure 1.

Since the data is preliminary and across three farms we should not get hung up on breed differences. What is vital is that there is a marked response on lamb performance at varying BCS at lambing with one BCS unit increase delivering 5.4kg extra lamb liveweight weaned.

The relationship between BCS at mating and the scanned litter size is shown in Figure 2.

As can be quickly seen there is a direct positive influence of increasing BCS at mating irrespective of breed type or year analysed. The effects of last summer’s drought also backs up the theory that what happens three, six, 12 months or even for a longer previous period will have a knock-on influence on performance. This is because ewes which lost significant condition due to drought are showing up with lower litter sizes.

Lesley also looked at the effect of weight loss from mating to scanning and summarised that ewes that lose weight/BCS from mating to scanning do not perform as well as ewes who gain BCS and weight, with this holding true for ewes that are in good condition at the start.

Young ewes were singled out as being particularly vulnerable to losing body condition and weight and the resultant effect of this in compromising lifetime performance. Lesley says that analysis of the data has also allowed them to start looking at target lamb weights at 56 and 90 days of age. The flocks which worked with the target weight at 56 days were highlighted as 20kg liveweight. Lambs that weighed below 17kg liveweight never compensated for this low performance in early life and continued to perform poorly.

BCS as a management tool

Lesley said that BCS can be successfully used as management tool that is repeatable and a relatively easy technique to learn and implement. She said that the next area to explore is how weight changes affect performance. This is a trickier area as there is a wide variation between breed types but it could become a useful indicator for individual ewes or as use within a flock.

When questioned on if she was fearful of ewes being in too good of condition and the resulting effect that may have in presenting lambing issues, she said that she is more relaxed on ewes being a little strong in condition with this being a much better position than ewes lacking condition. A condition score of 3.0 to 3.5 was highlighted as being the optimum range at lambing, while single-bearing ewes and young ewes were highlighted as being the ones to watch for excessive condition. Young ewes were highlighted as also excessive internal fat accumulation in young life appears to stay with them for longer.

The other aspect BCS was highlighted as playing a management role is in the identification of poor-performing ewes and underlying health issues. Poor BCS will often throw up issues such as persistent lameness, iceberg diseases or a common feature Lesley has seen in aged ewes is problems with pre-molar teeth limiting a ewes’ ability to perform on a forage-based diet.

Greater use of forage

Lesley also discussed the importance of increasing the volume of forage in the diet of the ewe be it grazed grass, conserved forage or forage crops. She highlighted grazed grass being five times cheaper than concentrates and as such having huge potential to reduce costs. This is detailed in Figure 3 which also shows that high-quality silage is less than half the price of concentrates.

Lesley questioned the traditional thinking of a ewe’s ability to consume sufficient forage reducing significantly in late pregnancy and in turn increasing the need to introduce expensive concentrates. She said that ewes have adapted and evolved over time to utilise and store energy when it is not required so it can be used when it is most needed. She said that a ewe’s rumen also has an ability to work faster in late pregnancy which compensates somewhat for any limitations in intake. She used an example of a large-scale sheep enterprise feeding a TMR diet three times daily to ewes resulting in very low concentrate usage. The caveat to this statement is having high-quality silage and good-feed management with adequate feeding space.

The stand-out quotes

There were three more very good presentations delivered by Dr Nigel Kendall from the University of Nottingham, Dr Tim Keady, Teagasc and Declan McEvoy, IFAC.

Nigel Kendall spoke about mineral supplementation in sheep highlighting how minerals can increase performance provided they have been shown to be required.

Tim Keady delivered learnings for the EU-wide SheepNet project with a particular focus on lambing while Declan McEvoy discussed how succession planning done early will allow a plan to be put in place that limits exposure to tax and brings about the best outcome for all parties involved.

These presentations will be covered in detail in the next few weeks but in the meantime below is a number of the standout quotes.

There is a fourfold increase in gross margin comparing the top sheep farm to the bottom producing farms. Output is driving this – most farms will have similar costs but if you can get your output right there is a significant margin to be made from sheep with the top performing farms generating a positive gross margin of €1,195/ha.

– Professor Gerry Boyle, Teagasc director challenges farmers to utilise Teagasc to improve their business.

Minerals are often the first port of call to deal with a problem when they should be the last thing. Grass supply or ‘vitamin G’ and nutrition should be first and foremost followed by adequate water, then parasites and lastly minerals.

– Nigel Kendall outlining that minerals are often used where not required

Be cynical looking at minerals. Ask the mineral company to show you evidence they work. If your animals need minerals you will get a benefit but consider also if the benefit will cover cost of treatment. Remember also you can overfeed minerals, that is becoming a growing problem.

– Nigel Kendall.

If the EU increased the average litter size by 0.1 of a lamb it would result in an extra 64,000t of sheepmeat produced from the EU’s 85m sheep flock and in turn increase self-sufficiency to 92%. Maize meal is €30/t cheaper than barley and costing €40/t less – it’s like buying a Charolais but only having to pay the price for a Friesian.”

– Tim Keady discussing the reward of increasing ewe productivity.

There is a greater focus in tax now shifting from income to wealth and unfortunately land is seen as a wealth generator. There appears to be a push to lower tax relief limits so you need to start planning in good time to achieve the best outcome for all involved.

– Declan McEvoy, IFAC says that while succession and transferring of the family farm may seem a long way off, early investigation will certainly reap rewards

The importance of making a will and updating it regularly and ideally at least on a yearly basis cannot be overstated. No one wants to be in the situation of an intestate will. For parents if you are transferring the family farm to one child and sites to other children do it before the farm is transferred as a sibling transferring site will be exposed to tax.

- Declan McEvoy.