Ewes fed cobalt at tupping will produce thrifty lambs that are better able to survive in outdoor lambing conditions.
John Vipond of the Scottish Agricultural College said farmers shouldn’t focus on the nutrition of ewes in the last six weeks of pregnancy only. “Ewes that are fed cobalt when they are producing eggs have lambs that are better behaved at lambing,” he told farmers at NSA Welsh Sheep 2011. “Cobalt is involved in switching genes on, even very early in life genes can be switched on. We can’t rely on feeding sheep in the last six weeks of pregnancy only.”
Dr Vipond says 80% of lamb mortalities are the result of starvation, hypothermia and mismothering. Many of these deaths could be avoided if lambs were stronger and thriftier at birth. Ewe nutrition is central to this, he said, with well developed lambs resulting from ewes fed the correct nutrition.
“A lamb loses heat four times faster when it’s on the ground than when it is standing up. When lambs are standing up their muscles start working and this generates heat,” says Dr Vipond.
“There are fewer mortalities with heavier lambs, ewe nutrition has a big influence on lamb birth weights.”
High quality protein is integral to this nutrition. David Thornton, technical manager with Rumenco, advises farmers to look in detail at the level of undegradable protein in feed.
He is also an advocate of feeding whole cereal to pregnant ewes. “It has good ME values and can be well digested and importantly it has a high level of phosphorous. Cereals tick a lot of boxes,” he said.
Mr Thornton recommended that farmers get their forages and pastures analysed to determine mineral and trace element levels. “With analysis you can see what there is in there and more importantly what’s missing,” he said.