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Suffolk trials show easier care potential

Suffolk trials show easier care potential
07/05/2008 14:00:00

Early results from a trial comparing the performance of the progeny of 10 Suffolk rams indicate significant potential for cutting costs by using easier care traits.

The work has also demonstrated that breeders do not need to turn to New Zealand to get hold of the genetics they need.

Three groups of lambs sired by New Zealand-bred tups imported as embryos, high index rams and traditional tups selected on eye were bred at Morfa Mawr, Ceredigion, out of 506 mixed-aged Mule ewes.

Technical help was provided by the breeding company Innovis to collect semen to artificially inseminate the ewes, which were heat-synchronised. The aim was to ensure all the different types of Mules in the flock were matched to the different sire groups.

Seventy-five per cent conceived and the ewes scanned at 1.93 lambs/ewe. In early February, 99% of 702 lambs were born alive.

Janet Roden, who supervised the work, told breeders who attended a flock inspection on the trial farm, owned by the Institute of Biological, Environmental and Rural Sciences, Aberystwyth, that ewes received identical post-insemination treatment.

Blind performance monitoring

In fact, eartag records were locked away so there was “truly blind” performance monitoring. Even she did not know which lambs had been sired by the different tups until shortly before the inspection was staged.

When the Abersystwyth University research associate presented lambing and pre-weaning results, she said the greatest variation was found within populations of lambs born to the different types of sire rather than between populations.

Only 2.3% of lambs were lost within the first 48 hours after parturition, with no differences in survival rate between lambs sired by the different sire groups.

The average birth weights were 6.1kg for singles and 5kg for twins. Lambs sired by the four New Zealand rams were marginally lighter at birth and presented fewer lambing problems.

Monitors recorded the level of help ewes needed, on a scale ranging from none to “call the vet”. Overall, only 6% of lambs required assistance to start suckling and most of these were triplets.

Individual and groups of sires

Lamb vigour was assessed and it was found that variation – judged by the ability to stand up and suckle – was greater between individual sires than between groups of sires.

At eight weeks, the heaviest lamb weighed 34kg, singles averaged 26kg and twins 21kg. Those out of UK high-index rams averaged 21.6kg, those sired by traditional Suffolks 20.7kg, while New Zealand-sired lambs averaged 20.0kg.

All the progeny were also assessed for dagginess on a scale of 1 to 4. While 15% of the New Zealand-sired lambs were dirtier than Dr Roden would like, they were slightly less daggy than the 25% in the two other sire groups, though one traditional tup was ranked second overall for cleanliness.

An attempt will be made, using faecal egg counting, to assess the link between dirtiness and variation in worm resistance between the 10 sires.

A full breakdown of variations in lambing ease, early vigour and weight gains will be published when Dr Roden has details of time to slaughter, carcass weights and lamb grades. The aim is to get lambs that classify 3L without using any creep feed.

“The initial results have revealed considerable variation in the easy care attributes of lambs sired by different rams that breeders can exploit,” said Dr Roden.

Immediate labour and cost reduction

Robyn Hulme, Suffolk Society commercial director, agreed and claimed commercial producers could gain immediate labour and cost reduction advantages by sourcing rams recorded for easy-care traits.

“An increasing number of Suffolk breeders are now concentrating on selection policies emphasising minimum labour input. Over 250 members are recording lambing ease and lamb vigour.”

The trial proved beyond doubt the importance and advantages of recording, which had been society policy for a number of years.

Prys Morgan, industry development manager at Hybu Cig Cymru, which sponsored the trial, claimed the results showed how breeders could use performance recorded stock to meet their individual farm requirements.

The final report, including detailed costings, would appear on the HCC website later in the year.

CAP: Lambs by high index UK Suffolk tups had the highest eight week weights, while those by New Zealand bred sires were less daggy, said Janet Roden.

by Robert Davies (About this Author)

Suffolk trials show easier care potential

Ram performance trial compares New Zealand and UK genetics

Livestock | 9 May, 2008

SUFFOLK sheep breeders from across the UK visited a West Wales coastal farm to hear the initial findings from a ram performance trial comparing New Zealand and UK genetics.

The large-scale trial, which is still on-going, was set up to find if there was anything to be gained from using Suffolk rams with New Zealand genetics, and supposedly carrying easier care attributes, in UK commercial crossbred flocks – but so far little variation between the two has been found.

The comparison trial is being carried out at the Institute of Biological, Environmental and Rural Sciences’ Morfa Mawr Farm, Aberaeron, funded by HCC, Innovis and the Suffolk Sheep Society.

Dr Janet Roden

Credit: © FARMERS GUARDIAN please contact 01772 799445.

Dr Janet Roden, Aberystwyth University researcher, who runs the project.

Progeny from the 506 mixed age Welsh Mule ewes (ran as a commercial enterprise finishing lambs off grass without concentrates) are being compared not only on growth and carcase quality but also the level of shepherding required.

In all, 10 rams have been used – four New Zealand Suffolks, three high index UK Suffolks and three ‘traditional’ UK type Suffolks – on three identically matched groups of ewes inseminated on-farm in September.

On average the ewes scanned at 1.93 lambs per ewe inseminated and, at lambing in February, the ease of lambing, lamb vigour, ability to suck unaided, birth weights and losses were recorded for all the 702 lambs born. Ewes and lambs were turned out 24 hours after lambing and no creep has been provided.

The biggest different found so far (see panel) is that lambs sired by the New Zealand Suffolks had slightly lower birth weights and consequently required less assistance at birth than those sired by the high index UK sires.

“The lambing results have revealed some variation in the easy care attributes of lambs sired by different rams,” said Dr Janet Roden, the Aberystwyth University researcher running the project.

Further information will become available over the coming months on the general ease of management and slaughter data.

Full carcase analysis will also be carried out on all the lambs and a final report bringing together all aspects of the trial published later in the year.

“The lambing and pre-weaning results so far show there are some slight differences between the different types of Suffolk,” said Dr Roden.

“Perhaps most importantly there is a great deal of variation within all the populations – confirming the importance to commercial producers of always using the best information available to choose the best ram.”

Initial data from the trial

• Around 99 per cent of all lambs were born alive with only 2.3 per cent lost within the first 48 hours of life.

• New Zealand lambs tended to be lighter at birth and, therefore, had the highest percentage of easy lambing.

• Incorrect lamb presentation at birth gave rise to 80 per cent of the lambing assistance required.

• Some 97 per cent of singles and twin lambs overall sucked without assistance with those that did mainly being triplets.

• The variation between individual sires for vigour – judged on the ability to stand up – and to suckle was far greater than the variation between groups of sires.

• Average birth weights were 6.1kg for singles and 5kg for twins. At eight weeks singles were up to 26kg while twins were 21kg.

• There was little difference in the averages between the groups with the UK high index-sired lambs being marginally higher at 21.6kg. The UK traditional Suffolks were 20.7kg and the New Zealand Suffolks were 20.6kg.

• At eight weeks of age the lambs sired by both UK Suffolk groups were slightly heavier than lambs sired by New Zealand Suffolks.

• Lambs sired by the New Zealand Suffolks were slightly less daggy (15 per cent compared to 20-25 per cent for the UK-sired lambs) with one of the traditional Suffolk rams ranking second overall on cleanliness.