Do you want to know more about how we performance record our sheep at Innovative Sheep Breeding and how to use the figures in the selection of rams or tups to maximise the improvement to your flock?

We use Signet Breeding Services to evaluate our sheep so that we can use our best animals in the breeding programme. Using Signet, we get figures for traits that we cannot directly observe.

Signet is part of the AHDB a levy board to which everyone in the farming sector contributes. I pay for my flock’s analysis, but this would not be enough to fund the organisation, nor pay for any further research and development.

Signet works fairly and impartially to get results that benefit the whole industry.

SRUC (Scotland's Rural College) provides expertise and computing power to analyse the data.

Our data is analysed by a technique called BLUP (Best Linear Unbiased Prediction) This is the same technique that some of our competitors use. Innovis uses an in-house evaluation system. Wairere and High Country Romneys use SIL because their livestock links to other related animals on that system. None of these breeders figures are displayed on the internet, which is a downside for the end-user or customer.

If you want to independently verify the performance figures of the tups you are buying you must buy from a breeder who records with Signet.

It is important to note that genetic linkage between flocks is essential. It provides a larger and more accurate analysis but also allows for differences in environment and system to be taken into account and thus provides a comparison between flocks on different farms.

How do you use the figures that Signet provides?

You will see here an example of what Signet display for each recorded animal in our flock.

UK 0 364389 10562 is a historical and very influential ram at Innovative Sheep Breeding.

The bar chart shows his figures for each trait along with the level of accuracy. His accuracy levels are high because he has 354 recorded offspring, many of whom are now working ewes. The X-axis shows his position relative to the breed average for that trait.

(The displayed figures for this ram are calculated after including all offspring, all parents and all indirectly related animals in all linked flocks. This animal’s figures will change slightly with each data run despite his age.)

Here is our view of the available ebvs (estimated breeding values) and hopefully this will help you make the best decision in selecting a ram/tup. Here is a useful explainer from Meat and Livestock Australia if you need any clarification.

Lamb Survival and Maternal Ability

These two traits are easy for you the customer to assess. Higher figures can only be better, everything else being equal. Maternal Ability is in lamb kgs at eight weeks of age, and Lamb Survival is in extra lambs surviving to 8 weeks.

Growth rates

Eight-week weights and Scan weights give us the growth rates to 8 and 20 weeks respectively, and are closely linked. Growth rates are heritable and desirable, but you ought to be aware that they are positively associated with the Birth weight ebv, and actual birth weights will rise with improved growth rates. Additionally, improving growth rates will increase the flock’s mature size with time, if steps are not taken to control size.

Muscle depth

The muscle depth ebv relates to the depth of muscle in the lumbar area or chops and can only be a positive, unlike confirmation which will have ease of lambing implications.  Unfortunately, it is unrewarded by the current abattoir payment system.

Fat depth

Fat depth is a fine line to tread. It would be best if you choose values to maintain or correct the levels in your flock that best suits. Remember that too little fat negatively affects lamb survival and maternal ability, while too much is penalised at slaughter and reduces the weight of the fat lamb selection window.

Mature size

As with the above trait, it is a fine line, and it depends where you are now with your flock. Selection for improved growth rates tends to increase ewe size. However, the fat lambs from larger ewes will finish quicker, reducing days to slaughter. Signet is doing more work both on this ebv and the economics of mature size. If you struggle to keep good grass in front of your sheep, it would be advisable to keep size more under control.

Age at first lambing, Lambing interval and Longevity are relatively new traits and have low heritability and as such have a lower economic value than the major traits. At Innovative Sheep Breeding, we would advise that you concentrate on the primary traits unless it is a tie between two animals.

Worm resistance ebvs

We have spent a lot of time and money recording measurements for worm resistance with the anticipation that these will be significant traits that drive profit. However, Fecal egg counts are not a direct indication of the worms in a lamb’s gut, and Iga measurement in saliva turns out to be an unreliable measurement of Iga in the stomach.

Additionally, some belated research showed inadequate repeatability of these measurements. When combining this with a series of very low initial heritability estimates, we have had to change tack. At the moment concentrating on growth rates is more profitable as slaughtered lambs do not put worms back onto the pasture. In the longer term, there is hope that a new variation of the Iga ebv, the serum Iga ebv, will be a lot more promising.

The measurements for this antibody are through a blood sample rather than saliva. We have already started collecting measurements with the help of Signet.

If anyone is trying to sell you quote “worm resistant” sheep at the moment or is pushing this in their sales literature, then at best, they are misleading. Worm resistant sheep are not a reality yet, unfortunately.

How do you work out which are the best sheep?

All sheep are a work in progress, and one person’s ideal sheep will be slightly different from another’s because of system and goal differences. However, it necessary to have a ranking tool. The index is the ranking calculation, and value judgements are inherent in its formula. It would be best if you used the figure as a guide and concentrated on individual ebvs. The priority has to be for “corrective mating” where necessary when selecting a ram.