Seek out that nutrition data
Planning ewe feeding and
meeting nutritional needs
was the theme of a MAFF
and ADAS organised
meeting in East Anglia.
James Garner reports
CHOOSING a compound ewe feed to balance forage is easier said than done because nutritional information on feeds is not readily available.
ADAS sheep consultant Gill Povey told a MAFF/ADAS meeting on ewe feeding at Otley College, Ipswich, Suffolk, that flockmasters must be prepared to seek out this information.
There are guidelines which can be followed to ensure that a good feed is offered, she said. "Energy supplied by the compound should be 12 MJ/kg DM for lowland ewes, with a protein content of 16, 18 or 20%."
But assessing protein content is complicated because protein quality is more important than total quantity in feeds, said Dr Povey. About 4-5% of protein should be of a bypass or undegradable type.
Trial work shows quality protein – soya or fishmeal – increases litter weights at birth and makes for healthier lambs. Quality protein also increases protein and antibodies in ewes milk, leading to faster growing lambs.
Despite being subject to debate in recent years because of EU wishes to ban it, fishmeal is still a good protein source and one that Dr Povey would recommend. "But cost is a problem this year; soya prices are lower than a few years ago, meaning fishmeal is not so competitive."
Besides checking protein quality, ensure energy in ewe rations is coming from the right combination of sugars and starches. Dr Povey advocated that at least 16% of total energy supplied was from sugar and starch, rather than fat.
Checking labels on bags or delivery slips will give a few clues to diet quality, she said. Oil should not be above 4-5% content, fibre 7-12% because it becomes indigestible above this and ash should be 10% at most. If it is higher this indicates a filler has been used in compounds.
All compounders must list ingredients in descending order of content, but percentage inclusion did not have to be given unless asked for, said Dr Povey. But molasses can provide a clue to inclusion levels. "Most mills include molasses in rations to make them run through plant machinery easily and improve palatability."
Molasses will mostly be included at 4-8% of ewe compounds. "Any ingredients listed below molasses will be at a low levels." Fishmeal could appear on feed labels below this, in which case its use would be neglible, she warned.
Other ingredients which did not provide nutritional value for sheep and should not feature on feed labels were coffee, olive pulp, shea nut, oat feed, grape pulp and cocoa residue, warned Dr Povey.
Ensure vitamins and minerals are included in diets at appropriate rates and consider having vitamin E added to compounds to promote lamb viability at birth and improve growth rates. Some compounders had increased vitamin E levels in feeds to 80iu, but it should be higher yet, said Dr Povey.
"On straw-based diets with high compound intakes, 100iu of vitamin E is enough, but on silage based rations 150iu of vitamin E is required."
• Check protein quality.
• Ensure enough sugar and starch.
• Find out about diet ingredients.