3 July 1998

Management shift can reduce lamb mortality

Changes in management has

seen lamb mortality fall to

6% on one Devon farm.

Simon Wragg reports

CLOSE attention to flock management has boosted lambing performance at the 140ha (340-acre) Slade Farm, West Anstey in Devon.

The farm, run by the Holland family, is one of four taking part in a MAFF-funded project aiming to reduce lamb mortality.

Lamb mortality has been up to 15% through to weaning for the 600-ewe flock comprising Exmoor Horn, Mule, North Country Mule and Scottish Blackface breeds, but this years figure is just 7% following a number of management changes (Livestock Feb 20).

Ewes were condition scored in autumn with those at condition score 2 or less going on to better grazing areas to improve condition. The remaining ewes were grazed on permanent pasture before being brought indoors for lambing.

Separating breeds – which lamb at different times – and those ewes with singles, doubles and triples for floor feeding supplementary concentrates has helped ensure all ewes have adequate feed with minimum amount of stress, says ADAS sheep adviser Charles Stone.

Floor feeding was a lot less work and helped reduce jostling and competition for feed, according to Norman Holland who farms the unit with his wife, Christine, and son, Andrew.

To reduce potential abortion risks, all bought-in replacement ewes will probably be vaccinated. "We are also considering only buying from EA-accredited flocks, although shortly we will breed all our own replacements," he adds.

Lamb mortality has been complicated by the inclement weather this spring – some lambed ewes with chapped udders had to be brought back indoors. Even so, greater attention in the lambing shed has meant fewer dead lambs, says Andrew Holland.

Of 1034 lambs born, the Hollands were set the task of having no more than 80 mortalities to weaning at about three months of age. That target has been beaten with just 68 deaths – a lamb mortality of just under 7% (see table).

Lambs have been white drenched before turning out on to silage aftermaths. Treatment for fly strike has also been administered. Because the ground is still wet, the Hollands are watching out for scald and treating cases by footbathing in a formalin solution.

But lambing performance may still improve as pre-tupping management starts earlier this year, explains Mr Holland. "We will be applying the same management to ewes this year starting with the run up to tupping in three months time. Ewes that have had difficulty lambing have been tagged and will be culled after weaning is complete."

The Hollands recognise they are culling harder now than before, but that should help ensure good lambing performance next spring. Teeth, feet, udder and lambing performance are all taken into account, and since the start of the project, a higher proportion of ewes in poor condition are selected for culling, says Mr Stone.

In addition rams will be checked prior to tupping, with each one turned over. On ADAS advice, Mr Holland also selected some rams for fertility testing. "One ram tested by the vet this year was infertile, but singling it out justified the cost of having four tups tested at £22 each.

"By keeping the management of the flock identical to this year, we should be able to see what effect the weather has had on lamb mortality," he adds.

Two seasons results should provide a clear picture of farm performance, says Mr Stone. This will allow objective assessment of the effect of introducing vitamin E supplementation in the third year of the project.

Vitamin E plays a crucial role in lamb viability, but can only be obtained from ewe colostrum, explains Mr Stone. "Therefore, if ewes have insufficient vitamin E in their colostrum, lambs may be less likely to survive."

The current recommendation on vitamin E intake for ewes is 22iu/kg DM concentrate, but recent research suggests this level may be too low. Trials are attempting to identify the optimum level to ensure good lamb viability.

SLADE FARM LAMBING

&#8226 Total no born 1034

&#8226 Lambs born dead 33

&#8226 Lambs lost – first week 23

&#8226 Lambs lost since first week 12

Ewes which have had a difficult lambing have been tagged and will be culled after weaning, says Norman Holland, while Charles Stone (inset) advises that rams are turned over and inspected closely before tupping.